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1
Arnet, Kevin Broc. "Cover crops in no-tillage crop rotations in eastern and western Kansas." Thesis, Manhattan, Kan. : Kansas State University, 2010. http://hdl.handle.net/2097/4086.
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Hurley, Shannon. "Oats as a Companion Crop for Alfalfa: Establishment Methods." TopSCHOLAR®, 1994. http://digitalcommons.wku.edu/theses/971.
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Companion crops are commomly seeded with alfalfa in the spring as an establishment method. The objectives of this research were to evaluate the performance of seedling Alfalfa (Medicago sativa L.) in terms of yield when grown with spring oats (Avena sativa) as a companion crop and to evaluate the amount of weed control in the alfalfa companion crop seeding, under various management practices. Six establishment treatments were imposed: (1) solo-seeded alfalfa raised according to standard procedures recommended for Kentucky, (2) solo-seeded alfalfa with a herbicide treatment, (3) alfalfa seeded with an oat companion crop and treated with a herbicide, (4) alfalfa seeded with an oat companion crop with harvest at 10cm to 21cm of height, (5) alfalfa seeded with an oat companion crop, oats removed for haylage, and (6) alfalfa seeded with an oat companion crop, allowing the oats to produce seed before harvest. In the first seeding year (1992) the alfalfa and oat companion crop that was treated with a grass herbicide had siginificantly higher yields than the check or alfalfa and oat companion crop that was allowed to produce seed. In the second seeding year (1993) there were no significant differences among the establishment methods. The second year of the 1992 seeding experiment had unexpected results. The alfalfa and oat companion crop treated with a grass herbicide had greater yields compared to all other treatments except the alfalfa and haylage oat companion crop treatment. These results indicate that proper management of the companion crop system for highest yields and best performance of alfalfa has not been determined or established.
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Okito, Pungu. "Origins Of The Y Genome In Elymus." DigitalCommons@USU, 2008. https://digitalcommons.usu.edu/etd/95.
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The Triticeae tribe DUMORTER in the grass family (Poaceae) includes the most important cereal crops such as wheat, barley, and rye. They are also economically important forage grasses. Elymus is the largest and most complex genus with approximately 150 species occurring worldwide. Asia is an important centre for the origin and diversity of perennial species in the Triticeae tribe, and more than half of the Elymus are known to occur in the Asia. Cytologically, Elymus species have a genomic formula of StH, StP, StY, StStY, StHY, StPY, and StWY. About 40% of Elymus species are still unknown for the genomic constitution and some have questionable genomic combination. However, the origin of the Y genome is unknown. In order to identify the origin of the Y genome, 212 accessions of Elymus, Pseudoroegneria, and Hordeum species were tested using a Y genome specific Sequence Tagged Site (STS) marker. We obtained evidence supporting the hypothesis that the Y genome in some Elymus species shared a progenitor genome with the St genome. Our study suggested that Pseudoroegneria spicata (PI 232134), P. ferganensis (T 219), and P. libanotica (PI401326) are the donors of the Y genome in the Elymus species. The DNA sequences of the Y-genome marker in these three Pseudoroegneria species are more similar to those obtained from Elymus species having the Y genome than those from Hordeum marinum and H. murinum, making the Xa and Xu genomes less likely the donors of Y genome.
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Lueck, Andrew Bruce. "Environmental Conditions, Variety, and Application Timing Influence on S-Metolachlor Sugarbeet Crop Safety." Thesis, North Dakota State University, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10269346.
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<p> Glyphosate-resistant weeds in North Dakota and Minnesota sugarbeet growing regions have necessitated research on S-metolachlor. S-metolachlor can be applied early-postemergence in sugarbeet but has not been labeled preemergence as reductions in sugarbeet safety have been observed. Field and growth chamber experiments were conducted to determine crop safety from S-metolachlor applied preemergence. S-metolachlor readily bonds to soil clay and organic matter. High clay and organic matter soils buffer S-metolachlor from soil solution and increase crop safety. Sugarbeet emergence was affected by soil series, temperature, and soil water, but was not affected by S-metolachlor or S-metolachlor rate. S-metolachlor affected sugarbeet growth, but a rate of 0.54 kg ai ha<sup> -1</sup> was safe across soils and growing conditions. No differences in varietal tolerance were observed. S-metolachlor applied immediately after planting or at the cotyledon and two-leaf stage injured sugarbeet less than application 3, 5, or 7 d after planting.</p>
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Gonzalez, Cesar. "Response of Three Cultivars of Bell Pepper (Capsicum Annuum L.) to Mulching & Irrigation." TopSCHOLAR®, 1988. https://digitalcommons.wku.edu/theses/2411.
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The effect of black polyethylene mulching and drip irrigation on the yield and quality of three cultivars of bell pepper was studied during the 1987 growing season. This study was conducted on a Pembroke silt loam soil on the Western Kentucky University Farm in Bowling Green, Kentucky. The experimental design was a split-plot arranged in randomized complete blocks in four replications with treatment as the main plot and cultivars as the sub-plot.
'California Wonder,' 'Lady Bell F1 Hybrid: and' Keystone Resistant Giant' cultivars of bell pepper were established in the field during the last week of May. The cultivars were grown using black polyethylene, with application of irrigation (no mulch) and without irrigation or mulch (check) Irrigation was initiated in early August and continued throughout the remainder of the growing season; the amount per application was 158.8 m3/ha.
At harvest, mature green fruit were removed from the plant, weighed, and classified as grade I or II. There were significant differences at the 5% level in the yield of the cultivars. There were significant differences at the 5% levels among the yields of the treatments. the higher yield was obtained with irrigation, followed by the use of mulch. The better yield under each of the three treatments was obtained with the cultivar Lady Bell.
The production of grade II peppers Was higher than the production of grade I peppers, the average yield was 48.82 MT/ha, and 21.99 MT/ha, respectively. The yield of bell pepper grade II was higher in all three treatments.
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Hafner, Timothy. "The Effects of Within-Row Spacings & Cultivars on the Yield of Bush Snap Beans (Phaseolus vulgaris L.)." TopSCHOLAR®, 1990. https://digitalcommons.wku.edu/theses/2428.
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The effects of within-row spacings and cultivars on the yield of bush snap beans (Phaseolus vulgaris L.) were studied in two experiments. In each experiment, two cultivars and four within-row spacings (8, 15, 23 and 30 cm) were arranged in a split-plot with four replications. Spacing treatments were the whole plots and cultivars were the split plots. In 1988, the two cultivars were 'Blue Lake 274' and 'White Half Runner'. In 1989, the cultivars were 'Blue Lake 274' and 'Kentucky Wonder 125'. All rows were spaced 91 cm apart. Pods were harvested and oven dried. The data were subjected to analysis of vlriance procedure for a split-plot design, assuming a fixed model.
In 1988, White Half Runner was significantly higher yielding than Blue Lake 274. In 1989, yield of Kentucky Wonder 125 was significantly greater than that of Blue Lake 274.
Bean yields were significantly influenced by spacing treatments in 1988 and 1989. Yields per plant were significantly higher for the 30-cm than for the 15- and 8-cm spacings. Yields for the 23-cm spacing treatment were significantly higher than those for the 8-cm treatment. Yields per meter of row showed no significant differences at any spacings. The linear effect for spacings was significant for both yield per meter of row and yield per plant in 1988 and 1989.
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Thompson, Leslie. "Efficacy of Sucker Control Method and Effect of Topping Height on Axillary Bud Growth in Dark Fire-Cured Tobacco." TopSCHOLAR®, 2001. http://digitalcommons.wku.edu/theses/640.
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The removal of terminal buds (topping) and sucker control are two practices that have an impact on yield and quality of dark tobacco (Nicotiana tabacum L.). Topping breaks apical dominance and encourages the growth of axillary buds (suckers). Following topping, growth regulator chemicals known as suckercides are commonly used to prevent axillary bud growth. Research has demonstrated that topping time, height, and sucker control method influence the quality and yield of the final product. Delaying topping past a critical developmental stage has been shown to reduce leaf yield. Topping height varies among geographical regions with most dark tobacco producers topping to a height of 12 to 16 leaves. Previous studies indicate that plants topped to 16 leaves had higher leaf yields than those topped to 12 leaves if late-season soil moisture was adequate. The opposite effect was observed when late-season soil moisture was below average because the small upper leaves on plants topped to 16 leaves did not receive the moisture needed for proper development. The moisture they did receive could have been diverted to improve the yield and quality of the larger, more valuable leaves if the smaller ones had been removed. Several options exist for chemical control of tobacco axillary buds ranging from contact to systemic materials. Performance of these materials is influenced by several factors including environmental conditions prior to and following application. Research plots were established at Western Kentucky University's Agricultural Research and Education Complex in Bowling Green, Kentucky to evaluate the efficacy of various sucker control methods and evaluate the effect of topping height on axillary bud growth. Data collection was completed in the summer of 2000. Three sucker control methods and three topping heights were investigated. The first sucker control method was a single application of a local systemic suckercide at topping. The second method was a sequential application using a contact suckercide at topping followed by a local systemic applied seven days later. The third method, which served as the control, was topping the plants but not applying any suckercides. The experiment utilized a split-plot design with 9 treatments and 4 replications. The plots consisted of two 7 m rows per plot, with 102 cm row spacing and 89 cm in-row spacing. Data collected include number of suckers per plant and kilograms of sucker biomass per plant. Statistical analysis indicated no sucker control method by topping height interaction; thus sucker control and height data are discussed separately. Suckers per plant and sucker biomass per plant did not differ among those plots receiving a suckercide application. Topping height did not influence sucker number or biomass.
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Mathews, David. "A Comparative Study of Composted Organic Wastes and IBDU Fertilizer in Nitrogen Utilization by Bentgrass Cultivars." TopSCHOLAR®, 2001. http://digitalcommons.wku.edu/theses/675.
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This research project that was conducted to provide evidence that composted organic waste materials do provide comparable nitrogen absorption efficiency in relation to an organic slow release fertilizer. Western's compost facility supplied the two different organic wastes, which had been composted for 1 year. The materials used were composted urban leaf litter, sawdust/manure mixture at a 50/50 ratio by volume and an organic fertilizer IBDU. These materials were applied to one cultivars of (Agrostis capillaries) and three cultivars of (A. palustris) at the rate of .S^/IOOO**2 in the months of April, June, and September. The plots were sampled one month after application to evaluate the nitrogen concentration of the leaf and thatch material. The nitrogen concentration was measured by using a Leco 2000 CHN provided in the Dept. of Chemistry. In comparison of N recovery in leaves, "Exeter" had lower N concentration than the other cultivars in October and no difference in May and July of the first year. The leaf concentration for the second year showed that Penncross and L-93 were lower in May and were the same for the other two sample dates. There was no difference found in the N concentration of thatch among the fertilizer sources for both years. IBDU showed better N recovery in all but the last sample date where all treatments were the same.
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Sabal, Harry. "Molecular Characterization of Citrus Tristeza Virus Isolates in Commercial Citrus Grown in Belize." TopSCHOLAR®, 2001. http://digitalcommons.wku.edu/theses/699.
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Isolates of Citrus Tristeza Virus (CTV) in Belize may be causing inverse stem pitting, stunting, and slow decline on sweet and sour orange rootstock combination on field trees. One isolate on Cleopatra mandarin rootstock expressed no field symptoms but may be a possible source of a detrimental isolate to more susceptible citrus rootstock combinations. Field plants and field source inoculated indicator plants were used in this study. The first objective was to determine whether field trees of sweet Valencia orange trees that expressed symptoms of CTV would test positive to a polyclonal (mild and severe symptoms) and a monoclonal (severe decline) antibody. Of the 81 trees tested, 56% tested positive to a polyclonal antibody G-604. None of the trees tested positive to the monoclonal antibody MCA-13. The second objective was to determine the biological and serological reactivity on host indicator plants of some of the most symptomatic trees having highest optical density value readings from the ELISA test. Mexican lime showed mild to moderate vein clearing on three of the isolates tested, while sweet orange showed mild to moderate translucent veins on two of the isolates tested. Four isolates from the indicator host plants tested positive to polyclonal antibody G-604 but none tested positive to MCA-13. The third objective was to determine if there were any differences among the nucleotide sequences of three CTV isolates. The CTV coat protein gene (CPG) of isolates which reacted to a polyclonal antibody G-604 but not to monoclonal antibody (MCA-13) was selectively amplified by polymerase chain reaction from infected tissue extracts and sequenced using negative sense CN 407 primer. All three isolates revealed between ninety-eight and ninety percent significant identities to known CTV isolates previously characterized from citrus growing regions around the world.
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Oveson, Dawn. "Efficacy of Soybean Herbicides on Annual Morninglory." TopSCHOLAR®, 2001. http://digitalcommons.wku.edu/theses/691.
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Field experiments were established in 2000 and 2001 at the Agricultural Research and Education Complex in Bowling Green, Kentucky to evaluate herbicide efficacy on annual morningglory (Ipomoea spp.) species and other weeds. A randomized complete block design was utilized in each study with each treatment being replicated three times. Plots consisted of four 76 cm rows, 9.1 m in length. The two center rows of each plot were treated, with the outside rows of each plot serving as a weedy check. Crop response, weed control, and grain yield data were collected. Four different experiments were conducted. Two experiments utilized treatments of glyphosate and sulfosate alone and with tankmixes on glyphosate-tolerant soybeans. Two experiments examined various herbicide tankmixes applied to non-glyphosatetolerant soybeans. Soybean injury influenced by postemergence treatments of glyphosate and sulfosate alone and with chlorimuron-ethyl ranged from 0 to 5% four days after treatment (DAT) with the addition of chlorimuron-ethyl resulting in greater injury. Morningglory control 14 DAT ranged from 48 to 63% with sulfosate at 700 g ai/ha providing less control than glyphosate at 1120 g ai/ha. No treatment differences occurred 29 and 42 DAT. No statistical differences among treatments occurred among other weed species evaluated. Soybean injury influenced by postemergence treatments of glyphosate and sulfosate alone and with fomesafen and chloransulam-methyl 4 DAT ranged from 0 to 17% with the addition of fomesafen resulting in greater injury than the addition of chloransulam-methyl. Momingglory control 14 DAT ranged from 60 to 88% with glyphosate + imazethapyr at 840 + 71 g ai/ha providing the least control and sulfosate + fomesafen at 700 + 201 g ai/ha providing greater control. Soybean injury influenced by pre and postemergence treatments 7 DAT ranged from 0 to 30% in conventional soybeans. Applications of carfentrazone resulted in the greatest injury. Momingglory control 20 days after planting (DAP) ranged from 0 to 99% with chloransulam + sulfentrazone providing the highest control. Momingglory control 28 DAT ranged from 30 to 99% with s-metolachlor + metribuzin + acifluorfen + fenoxaprop-ethyl + fluazifop-P providing the least control. Common cocklebur control ranged from 13% to 97% 20 DAP with pendimethalin + imazethapyr providing the least control. Treatments containing aciflourfen + bentazon controlled common cocklebur > 80% 28 DAT. Soybean injury influenced by preemergence and postemergence treatments 7 DAT in conventional soybeans ranged from 0 to 33% with sulfentrazone + clomazone + chlorimuron-ethyl + carfentrazone resulting in the greatest injury. Momingglory control 7 DAT ranged from 0 to 99% with sulfentrazone + clomazone plus chlorimuron-ethyl + carfentrazone having the greatest control. Momingglory control 28 DAT ranged from 82 to 94% with no differences among treatment.
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Kelley, Tracy. "Efficacy, Phytotoxicity, and Cover Crop Response of Herbicide Combinations in Dark Fire Cured Tobacco." TopSCHOLAR®, 2000. http://digitalcommons.wku.edu/theses/724.
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Field studies were established during the summer of 1999 at the Agricultural Research and Education Complex of Western Kentucky University to evaluate efficacy, phytotoxicity, and cover crop response of herbicide combinations in dark fire cured tobacco. A randomized complete block design was used with nine treatments replicated three times. Hydroponic tobacco transplants (c.v. 'TND950') were established on May 20,1999 in a conventionally tilled system on a Pembroke silt loam (Mollic Palleudalf) with a pH of 5.8 and an organic matter content of 1.2%. The transplants were established at a population of approximately 10,278 plants/ha. Herbicide treatments were applied on May 19, 1999 with a CO2 backpack sprayer. Sulfentrazone as Spartan 75DF was applied in all nine treatments at a rate of 0.47 kg pr/ha. Six of the nine treatments included various rates of clomazone as Command 3ME. Two of the nine treatments included napropamide as Devrinol 50DF. Visual evaluations of crop phytotoxicity due to herbicide application were recorded at 21 and 44 days after treatment (DAT). Weed control was evaluated at 21, 29, 44, and 58 DAT for the following species: Ipomoea hederacea L. (Ivyleaf morningglory), Amaranthus hybridus L. (smooth pigweed), and Eleusine indica L. (goosegrass). Crop injury and weed control evaluations were recorded on a 0-100% scale with 0 representing no injury and/or no control and 100 representing plant death. After crop removal, two types of tillage were performed to examine wheat injury effects due to tillage. One subplot was moldboard plowed and disked while the other subplot was disked. Following tillage operations, winter wheat (Triticum aestivum) was planted on October 30,1999 at a rate of 134.68 kg pr/ha. Visual wheat chlorosis evaluations of each subplot were recorded and based on a scale of 0-100%. Stand counts were taken in the subplots to examine stand loss due to treatment. Wheat aboveground biomass was harvested from each subplot to evaluate the relationship between wheat growth and herbicide rate. Sulfentrazone alone provided >66% control of Eleusine indica, >96% control of Ipomoea hederacea, and >88% of Amaranthus hybridus at all evaluation dates. When combined with 0.584 L pr/ha clomazone, sulfentrazone provided >82% control of all weed species 58 DAT. Sulfentrazone combined with > 1.17 L pr/ha clomazone provided > 86% Eleusine indica control, >60% Ipomoea hederacea control, and >84% Amaranthus hybridus control. Sulfentrazone combined with 1.12 kg pr/ha napropamide provided >71% control for all weed species at all evaluation dates. However, sulfentrazone plus 2.24 kg pr/ha napropamide provided only >55% control of species at all evaluation dates. Wheat chlorosis was affected by increased rates of clomazone combined with sulfentrazone at both 25 and 41 DAP (days after planting). Fresh weight also exhibited a trend of decreased mass as clomazone application rate increased. Addition of >1.75 L pr/ha clomazone decreased stand count at both evaluation dates, as compared to the sulfentrazone treatment. There were no differences in stand count between napropamide rates in either stand count evaluation. Wheat chlorosis 25 and 41 DAP was greater in plots that were not moldboard plowed. Areas moldboard plowed and disked exhibited less chlorosis, but tillage had no significant effect on wheat biomass or stand count.
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Tawhid, Aslam. "Effects of Soybean Cultivars and Planting Dates on Biomass Production." TopSCHOLAR®, 1994. http://digitalcommons.wku.edu/theses/952.
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Soybean [Glycine max (L.) Merr.] is a valuable source of edible food and organic nitrogen. Soybean cultivar development and cultural practices have been directed toward seed production rather than forage or green manure production. Recent environmental concerns have resulted in renewed interest in the use of organic matter in agriculture. The objective of the present investigation was to determine the effects of cultivar maturity differences and planting dates on biomass production of soybean. The research was conducted on the Western Kentucky University Farm in 1993. The experimental design was a split-split-plot with four replications. The three planting dates (June 2, June 16, and July 6) were main-plots, the three harvest dates were split-plots, and the five cultivars were split-split-plots. The cultivars and their maturity groupings and areas of adaptation are as follows: 'McCall' (00, Minnesota), 'A2506' (II, Iowa), 'FFR561' (V, Kentucky), 'Perrin' (VIII, South Carolina), and 'Laredo1 (undesignated maturity, forage cultivar). Each experimental unit was 45 m2. Seeds were inoculated and broadcast at the rate of 175 kg ha-1 and covered by disking. Average biomass production (oven dry basis) decreased progressively (2918, 2450, and 2088 kg ha-1) for the later planting dates. For the June 2 and June 16 planting dates, biomass yields increased for successive harvest dates; however, for the July 6 planting date, biomass yields did not differ for harvests 2 and 3. When cultivars were compared at the early bloom stage, later maturing cultivars produced more biomass. Laredo was consistently among the highest producers. There were significant interactions involving planting dates, harvest dates, and cultivars. Soybean stands and yields were reduced by inadequate seed covering, by insufficient soil moisture, especially the second planting, and by competition from johnsongrass and pigweed. However, these results indicate that soybean is a good source of green manure during the summer.
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Coles, Joanna. "Efficacy of Herbicide Combination on Burley and Dark-Air Cured Tobacco." TopSCHOLAR®, 2003. http://digitalcommons.wku.edu/theses/586.
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The efficacy of herbicide combination on burley and dark air-cured tobacco Nictotiana tabacum were tested in field research plots in the summer of 2000 at Western Kentucky University's Agricultural Research and Education Complex. The randomized complete block design contained six treatments replicated three times in each of the two experiments (burley and dark air-cured tobacco). Transplants (cv. 'TN 97' and cv. 'KY 160') were established on June 2, 2000 in a conventionally tilled Pembroke silt loam soil with a pH of 6.5 and organic matter content of 12 g/kg. Herbicide treatments were applied on June 1, 2000 with a CO2 backpack sprayer. Six treatments were applied to both burley and dark air-cured plots. Sulfentrazone was applied alone and in combination with either clomazone, pendimethalin, or napropamide. A sulfentrazone + clomazone combination followed by sethoxydim, as well as a clomazone + pendimethalin tank mix were also evaluated. Weeds targeted for control were: Ipomoea hederacea L. (ivyleaf morningglory), Amaranthus hybridus L. (smooth pigweed), and Eleusine indica L. (goosegrass). Sulfentrazone alone provided >69% control of smooth pigweed and >89 % control of ivyleaf morningglory in burley and dark-air cured tobacco. At 21 days after treatment (DAT) the combinations of sulfentrazone/pendimethalin, sulfentrazone/clomazone/sethoxydim, and clomazone/pendimethalin gave better control of smooth pigweed in burley tobacco than did sulfentrazone/clomazone, but there were no differences between treatments at later evaluation dates. In dark-air cured tobacco, at 21 DAT sulfentrazone and the sulfentrazone/napropamide combination provided better control of smooth pigweed than did sulfentrazone/sethoxydim, but there were no differences between treatments at later evaluation dates. With respect to ivyleaf morningglory control, addition of herbicide combinations did not provide an advantage to sulfentrazone alone. Goosegrass control in dark-air cured tobacco was > 85% at all DAT, and control was > 45% in the burley plot. Control of goosegrass in both types of tobacco was > 94% with the triple combination of sulfentrazone/clomazone and sethoxydim at all evaluation dates, yet all combinations provided >86% goosegrass control at all evaluation dates. Addition of herbicides to sulfentrazone, (with the exception of napropamide) provided an advantage to goosegrass control in burley tobacco.
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Canty, Amanda. "Comparison of Nutrient Concentration in Four Fertility Treatments After Poultry Litter Application to Orchardgrass and Sorghum-Sundangrass Hayfield Soils." TopSCHOLAR®, 2002. http://digitalcommons.wku.edu/theses/623.
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Field experiments were established in 2001 at the Agricultural Research and Education Complex in Bowling Green, Kentucky to evaluate soil fertility values before and after poultry litter application to orchardgrass and sorghum-sudangrass hayfields. A randomized complete block design was utilized with each treatment being replicated four times. Orchardgrass plots consisted of sixteen 7.6 m rows, 91 m in length and separated by alleys 4.6 m in width. Sorghum-sudangrass plots consisted of sixteen 7.6 m rows, 60.96 m in length and separated by alleys 4.6 m in width. Four separate fertility treatments were utilized: inorganic fertilizer (I), poultry litter applied to meet nitrogen requirements (N), poultry litter applied to meet phosphorous requirements (P), and poultry litter applied to meet phosphorous requirements with a supplemental inorganic fertilizer (NP). In the poultry litter applications, plant available P was estimated to be 80% while N availability was estimated at 50% the first year. Fifteen soil samples were taken in a random, representative manner from each plot of orchardgrass and sorghum-sudangrass prior to litter application and after each harvest. Soil samples were analyzed for pH, N, P, K, Mg, Ca, Fe, Cu, and Zn levels, which were evaluated based upon fertilizer treatment differences Water pH has statistically remained the same thus far, indicating that it is currently not determining nutrient availability among treatments in orchardgrass and sorghum-sudangrass soils. Nitrate concentrations exhibited increases in treatments N and P for orchardgrass soils, while sorghum-sudangrass soils indicated all three treatments N, I, and P were different from each other. There were no differences among treatments for ammonium in orchardgrass soils; however, sorghum-sudangrass soils exhibited a higher concentration in treatments P and I. In both orchardgrass and sorghum-sudangrass soils, treatment N exhibited an increase in phosphate, copper, and zinc concentrations over all other treatments; magnesium and potassium concentrations were highest in treatment N in sorghum-sudangrass hayfield soils. Potassium concentrations were higher in treatments P and N in sorghum-sudangrass soils and the NP and I in orchardgrass soils. Sorghum-sudangrass soils indicated a higher K concentration in treatment N from all other treatments. While orchardgrass soils exhibited no differences in Mg, sorghumsudangrass soils indicated a higher amount in treatment N from all other treatments. Copper and zinc both exhibit a higher concentration in treatment N in comparison to all other treatments in both orchard and sorghum-sudangrass soils.
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Pigg, Carol. ""Bound Together . . . By Blood and Soul": Donald Davidson's Strategic Retreat into the Myth of Life in the Old South." TopSCHOLAR®, 2000. http://digitalcommons.wku.edu/theses/692.
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Donald Davidson has often been called stubborn because of his refusal to let go of the Southern past and in his insistence that his writings be based on and in the regional concerns that he saw as fundamental to all Southern literature. In many ways, Davidson's loyalty to the Agrarian and Fugitive causes, which are best defined in these groups interest in keeping the South's history alive and maintaining an agrarian lifestyle, is his greatest contribution to the Southern and American literary canon. Despite this fact, though, Davidson is now, as he was during his lifetime, ignored because of the Regionalistic concerns that critics see in his writing. In the course of my thesis, I have striven to prove that Davidson is one of the most prophetic, prophetic in the biblical sense, since I believe that he can be compared to Hebraic prophets who spoke of doom and destruction that the people would face if they did not please God, of the Fugitive writers. His prophecies, I argue, are against industrialization of the South and warn the degenerate Southerner against forgetting the past, especially the Civil War. In the process of defining Davidson as a Southern writer and in defending his place in the Southern literary canon, I compare his "Lee in the Mountains" to Robert Penn Warren's Brother to Dragons, emphasizing the importance of secular original sin in the lives of two historical legends, Robert E. Lee and Thomas Jefferson, a fact that brings universal appeal to Davidson's greatest achievement. Turning away from topics of national, historical importance, I emphasize Davidson's attempt to define and defend Regionalism as an art form and necessary tool in the teaching of history. Here, I speak of Davidson's nonflction writings, including Still Rebels. Still Yankees, and Other Essays, of his only novel, The Big Ballad Jamboree, and "Lee in the Mountains" and argue that the importance of these works lies in the fact that he is waging a war against critics who see Regionalism as a catchphrase for Southern red necks, who refuse to let go of the past. After discussing Regionalism, I acknowledge the modern characteristics in Davidson's poetry, mainly angst, isolation, and silence, by tying them into Davidson's continual discussion of the past, which begins in "The Tall Men," where he speaks of his Tennessee Frontiersmen ancestors, "Lee in the Mountains," a poem in which Davidson turns to the most infamous, yet disenfranchised Civil War veteran, and The Long Street, which are a group of poems where Davidson speaks of the angst and loneliness that the modern Southerner feels in the modern world, where industrialization and shame have silenced the Southern man, who should be proud of his national heritage. As I looked to Davidson's writings to find why he is excluded from both the modern Southern literary canon and from the American canon, I found that we are slowly losing a national treasure. He may not be the writer that the other Fugitives were. He may not have been enjoyed the literary or financial successful that the other Fugitives and Agrarians enjoyed, but his writings are fundamental to understanding the Fugitive and Agrarian movements, since they were based on a yearning for an understanding of the past and because they fought for an Agrarian lifestyle. He may not have moved on, as Robert Penn Warren, John Crowe Ransom, and Allen Tate did, but I argue that his refusal to forget the past and give up the fight for the "cause" makes his writing great and is the reason that he should be returned to the Southern and American literary canons.
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Stiles, Maria. "Evaluation of the Persistence of Grazing Alfalfa Varieties." TopSCHOLAR®, 2002. http://digitalcommons.wku.edu/theses/638.
Full textAbstract:
The use of alfalfa (Medicago scitiva L.) for grazing is becoming more common. Alfalfa is the most widely planted legume, and is one of the most nutritional forage crops available. It is proposed that alfalfa was cultivated 4000 to 5000 years ago and produces the most protein per acre of any forage crop. Live weight gains for beef cattle grazing alfalfa average 230 to 360 kg ha-1. There is no cheaper way to harvest and utilize alfalfa than for the animal to harvest it directly. Most of the commercially available alfalfa varieties, however, were developed for hay production and thus do not always persist under grazing management. Recent advances in alfalfa breeding have provided "dual purpose" cultivars that are now available to producers. A grazing trial was conducted at the Western Kentucky University Agricultural Research and Education Complex in Bowling Green, Kentucky. Persistence and yield of six commercially available grazing-tolerant alfalfa varieties were evaluated to determine their response to rotational stocking by dairy cows. The varieties, Southern States Graze King, WL 324, Garst 645 II, WL 325 HQ, ABT 405, and Spredor III were established March 29, 2000 and harvested three times for hay throughout the year. Grazing was begun in April 2001 and ended in September 2001. Each plot was grazed when alfalfa reached a minimum height of 36 cm. Twelve dairy cows (nine Jerseys and three Holsteins) grazed each plot down to approximately 13 cm. Yield did not differ among varieties (P<0.05); however, there was a significant difference among varieties for stand count. The variety by harvest interaction was significant; when averaged across varieties, stand counts declined 48% during the whole season. Southern States Graze King with 8.8 plants 0.1m-2, was greater only than Spredor III with 6 plants 0.1 m-2.
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Beckort, Richard. "Evaluation of Three Coverings for the Overwintering of Container Grown Herbaceous Perennials in Kentucky." TopSCHOLAR®, 1987. https://digitalcommons.wku.edu/theses/2153.
Full textAbstract:
The purpose of this study was to evaluate three coverings for overwintering twelve varieties of container grown herbaceous perennials under Kentucky conditions. The twelve perennial varieties were started from seed in the spring and had been moved to one gallon containers by fall. In the first week of December, three blocks of containers were covered with one of the following: one layer of 4 mil, milky copolymer; one layer of quarter inch microfoam and one layer of milky copolymer; a sandwich of two layers of milky copolymer with 6 inches of wheat straw between them; the remaining block was left uncovered as a check.
The perennials were uncovered in the spring, observed, and evaluated. The single layer of copolymer and the microfoam and copolymer treatments had the most new growth. The growth under the copolymer and straw sandwich method was elongated and white. Only three containers in the uncovered treatment showed signs of regrowth.
The microfoam and copolymer and the single layer of milky copolymer proved to be the best coverings for the over - wintering container grown herbaceous perennials in Kentucky.
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Fox, Susan. "A Comparison of Chemical Composition & Fermentation Patterns of Alternative Silages to Whole Plant Corn Silage." TopSCHOLAR®, 1989. https://digitalcommons.wku.edu/theses/2346.
Full textAbstract:
A comparison of the relationship of fermentation to chemical composition was made for forages which were wilted and ensiled at 35 to 45 percent dry matter. Trial I consisted of three forages ensiled in October, 1981: interseeded soybeans and grain sorghum. whole plant corn with added anhydrous ammonia, and whole plant corn with shelled corn added at a rate of 150 kg/t of fresh forage. Trial II consisted of two forages ensiled in 1982: interseeded soybeans and pearlmillet, and wheat. Temperatures of fermentation were collected, and chemical composition during the first 25 days of fermentation analyzed.
Production data were also collected in Trial I. The cash expenses and yields do not indicate a significant advantage to either crop in this study in terms of yields and return over variables. In terms of plant nutrient content there was an advantage for soybean/grain sorgum silage in protein yield of 854 kilograms per hectare as compared to whole plant corn silage.
Temperature data collected on the forages in Trial I covered 57 days from October 8 through December 4. The maximum recorded temperatures for soybean/grain sorghum, corn silage with added anhydrous ammonia and the corn silage control were 37, 37, and 24 degrees Celcius. achieved by day 11, 4, and 11 of ensilement respectively. The rapid temperature increase for material treated with anhydrous ammonia confirmed previous reports. Small fluctuations occurred in silage temperatures but these were not correlated to ambient temperature. Temperatures declined very slowly in all forages, with the lowest reading for silages by day 57 recorded at 19 C for soybean/grain sorghum silage. Ambient temperature was not reached in the ensiled mass during the 57 day period in which data were recorded.
The soybean/pearlmillet ensiled in Trial II quickly reached a high peak temperature of 44 C at 4 days of ensilement, gradually decreasing over a 57 day period to 35 degrees on October 19. The silage did not reach a desireable pH. Initial forage pH was high, 7.4, dropped rapidly to 5.1 on day 5, but did not decline further in succeeding samples. Samples were low in lactic acid and high in acetic acid content.
Initial buffering capacities for both of the soybean mixture forages were considerably higher than the other forage materials. Buffering capacities at day 0 for whole plant corn, whole plant corn treated with anhydrous ammonia, soybean/grain sorghum, soybean/pearlmillet and wheat forages IA ere 19.4, 20.0, 35.3, 35.3. 38.6 and 22.2 milliequivalents/100 g of dry matter respectively. Increases in buffering capacities during fermentation were smaller for soybean/grain sorgum and soybean/pearlmillet . Buffering capacity increases for the forages were 133.5, 290.5, 69.1, 64.2 and 87.4%.
High ammonia nitrogen levels were found in samples of whole plant corn silage with added anhydrous ammonia obtained on days 10 and 20 of ensilement. These contained .282 and .351% ammonia-nitrogen and tested 18.0 and 20.1% crude protein. The increase in buffering capacity which occurrs with addition of anhydrous ammonia was confirmed by the higher acetic acid and pH levels, with corresponding decreases in lactic acid from samples taken days 10 and 25. Crude protein levels were 17.9 and 17.4 percent while the other samples contained only 10-12% crude protein. It appeared that application of anhydrous ammonia was not uniform throughout the silage. Where high concentrations of ammonia occurred fermentation was prolonged as indicated by excessive amounts of lactic and acetic acids and a high pH in these samples. Values for L(+) lactic acid ranged from .2 to .523 in fresh forage to 5.66% of dry matter on day 25. Concentrations of ammonia-nitrogen in the other silages ranged from .061 to .131%.
The low buffering capacity of whole plant corn silage was reflected by normal concentrations of lactate and acetate but a more acidic pH when compared to the other forages. Lactic and acetic acid production for soybean/grain sorghum silage was similar to that of the corn silage control. Corn silage pH was lower, however, throughout fermentation and reached a stable pH by day 5 of fermentation. The wheat silage went through a gradual fermentation with low lactic acid production, and an intermediary ending pH of 4.0.
Fermentation was essentially complete by day 10 in all silages as indicated by pH, buffering capacity, and lactic acid production: however, there was a tendency for buffering capacity and acetic acid content to increase in all of the ensiled materials throughout the 25 day collection period.
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Craft, Kortney E. "Economic Impacts of Drought on Kentucky Corn, Hay, and Soybeans." TopSCHOLAR®, 2011. http://digitalcommons.wku.edu/theses/1066.
Full textAbstract:
Understanding climatic impacts is important if we are to comprehend the relationship between climate and society. Weather phenomena can have environmental, economical, and social impacts. Drought is the natural hazard that affects people the most. It is also the most complex and least understood. There is no one universally accepted definition for drought which makes its examination difficult. Droughts’ duration is also difficult to determine because it has no clearly defined onset and end. Also, drought varies both geographically and temporally making uniform drought monitoring difficult. Since drought is difficult to monitor and access, drought impacts are often poorly documented. The purpose of this research was to quantify (in dollars) the impacts of drought on Kentucky’s agriculture. Drought has been recorded historically in Kentucky since the late 1800s. According to the Kentucky Climate Center, the most significant drought years occurred in 1930-31, 1940-42, and 1952-55. Analyses of these years are included as well as the most recent significant drought years in 1987-88, 1999- 2000 and 2007. Four of Kentucky’s important commodities, including corn, soybeans, hay, and beef cattle, were examined during the significant drought years. The total state revenue for these commodities was analyzed during severe drought years vs. non-severe drought years. The result of this research identified how much of a deficit severe drought causes on Kentucky revenue for each of these commodities. This research is important to the general public as well as planners and policy makers. Proper documentation of drought impacts will help identify drought vulnerabilities and result in better risk management and mitigation. Key Words: Drought, Agriculture, Impact Assessment
20
Coomer, Taylor Dayne. "Effect of Potassium Deficiency on Uptake and Partitioning in the Cotton (Gossypium hirsutum L.) Plant and Detection by a Crop Reflectance Sensor." Thesis, University of Arkansas, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10110014.
Full textAbstract:
<p> For cotton (<i>Gossypium hirsutum</i> L.) to grow and develop normally, plants need to uptake the necessary amount of nutrients and use those nutrients in a beneficial fashion. It is recognized that cotton needs a certain tissue concentration of ions to achieve and maintain growth rates (Siddiqi et al., 1987). One of the most essential and abundant nutrients in cotton is potassium (K), second only by mass to nitrogen (N) (Marschner, 1995; Oosterhuis et al., 2013). Potassium exists in the soil in four separate pools and moves through soil to roots mainly through diffusion (Rengel & Damon, 2008; Samal et al., 2010; Ogaard et al., 2001). Potassium plays a vital role in plant growth and metabolism. </p><p> The objectives of this study were to determine the Michaelis-Menten parameters for the high-affinity transport system (HATS) and low-affinity transport system (LATS) uptake mechanisms of cotton, observe how K is partitioned throughout the cotton plant over a growing season with differing K fertilization rates, and to determine if cultivars differed in values from currently available indices formulated for N-status detection from active sensors. It also set out to determine if these N-sensitive indices were sensitive to leaf K concentration and available K2O in the soil, and to evaluate the role these indices play in predicting yield. It was hypothesized that a high K hydroponic environment would lead to more K uptake by cotton roots, which would lead to an increase in VMAX and KM. It was also hypothesized that with increased K fertilization, there would be greater K uptake and larger shift to reproductive components due to the plant having more than enough K in all other parts enabling it to send more to the reproductive components, and that greater K rates would lead to higher yields across all cultivars. It was believed that normalized difference vegetation index (NDVI) would more accurately predict leaf K, available K2O, and yield than normalized difference red edge (NDRE), that NDVI and NDRE would more accurately determine the K parameters chosen than canopy chlorophyll content index (CCCI), due to the strong influence of the red-edge band in the index and that yield would be most accurately predicted by the CCCI, due to yield being influenced by both chlorophyll content and biomass, and the CCCI involving the red-edge band to reflect chlorophyll content and the near infrared band to detect biomass.</p>
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Penick, William Frazier. "Influence of Transplanter Modification and Previous Crop on the Production of No-Till Dark Tobacco." TopSCHOLAR®, 2013. http://digitalcommons.wku.edu/theses/1257.
Full textAbstract:
Dark tobacco (Nicotiana tabacum L.) has historically been produced usingconventional tillage practices. Soil is cultivated multiple times throughout a growing season leading to an increased incidence of soil erosion. No-till systems have been growing in popularity with the advent of new technology that has enabled the practice to be performed effectively and efficiently. With the recent expansion of no-till practices throughout the agricultural community, many crops have had success in producing comparable yields while reducing input costs and saving soil resources. For this experiment, a traditional tobacco transplanter was modified for use in a no-till environment. All modifications were fabricated without using specialty tools and made possible to be removed if desired or necessary. Frame extensions were designed and built to accommodate row cleaners and coulters. Tillage shanks were also added to aid in optimal furrow formation. Double-disc opening shoes replaced the original round point shoes and the curved edges of the rear drive wheels were removed, creating a flat surface to increase soil contact. Experimental no-till plots in fescue sod and soybean chaff residues were conducted alongside conventional tillage plots at the Western Kentucky University Agricultural Research and Education Complex in summer 2011. Five treatments, one conventionally tilled (Conv) and four no-till, were replicated three times within a randomized complete block design and used to determine the efficacy of transplanter modifications (consistency of depth, furrow closure, observed plant damage), survival of the transplants, and the amount of residue displacement. The four no-till treatments utilized different combinations including: coulter, row cleaner and shank (CRS), row cleaner and shank (RS), coulter and shank (CS), and shank only (S). These treatments demonstrated the functionality of each combination in comparison to conventional treatments. No treatment performed equally well in both residue locations. Plots in fescue residue utilizing a combination of coulter, row cleaner, shank (CRS), exhibited the lowest amount of root exposure, highest survival rate, and comparable cured weight when compared to conventionally tilled treatments. In soybean residue plots, the treatment operating with row cleaners and shanks (RS) had equivalent amounts of furrow closure to conventionally tilled plots. Pairing specific modification combinations with previous crop residue can provide furrow closure, transplant survival, and cured yield equivalent to conventionally tilled dark tobacco.
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Daniel, Kyle. "Asexual Propagation of Four Cultivars of Vaccinium Corymbosum and Weed Management in an Established Orchard of Vaccinium Corymbosum 'Bluejay' (Highbush Blueberry) in South Central Kentucky." TopSCHOLAR®, 2006. http://digitalcommons.wku.edu/theses/456.
Full textAbstract:
In response to the changing economy of Kentucky tobacco, producers are seeking an economically viable alternative that can be produced on a similarly small acreage. Blueberries are an emerging crop that satisfy the needs of these producers and are popular with consumers for their flavor and health benefits. In addition to selling the berries, local producers are experiencing much success selling blueberry plants to homeowners and other producers. However, the protocol for propagating specific cultivars under local environmental conditions is unknown. Rooting percentages for producers has been extremely variable. A two year study conducted at Western Kentucky University investigated asexual propagation of four commercially significant cultivars of Vaccinium corymbosum, highbush blueberry, 'Jersey', 'Elliot', 'Bluecrop', and 'Bluejay'. The study was a randomized complete block design with four replications. Cuttings were taken from a producer's field in Metcalfe County and planted in a bed of pure peat under a mist system at the Western Kentucky University Agricultural Research and Education Center. Propagation techniques were designed to closely mimic the systems used by producers. The effect of cutting phenology, rooting hormone, and cutting location along the stem was investigated as they affected rooting percentage, and dry matter mass of leaves, shoots, and roots. Hormones had no effect on rooting or growth of first year cuttings. The greatest rooting percentages and dry mass gain was found in descending order, 'Jersey', 'Elliot', 'Bluecrop', and 'Bluejay'. There was a correlation between location of the cutting and time of the year the cutting was acquired. Basal cuttings performed well early in the season, while apical cuttings performed well later in the season. The effects of four weed management schemes were investigated on berry yield components and new growth in an established orchard of 'Bluecrop' blueberries in Metcalfe County, Kentucky. The experimental design was a randomized complete block with four replications. Plots consisted of six established plants but data was collected on the innermost four. Treatments were weed-free strips 0.609 or 1.828 meters wide within the row, mowing, and an untreated control. Weed-free strips were maintained as necessary with directed sprays of labeled rates of glyphosate, a phloem-mobile, nonselective herbicide. Highly significant differences in new growth were noted during both years from the herbicide-treated plots compared with the non-treated plots. In 2005, highly significant differences were noted within total berry weight and berry weight per plant from the herbicide-treated plots compared with the non-treated plots. In 2006, highly significant differences were noted within total berry numbers, number of clusters per plant, and mean berries per cluster from the herbicide-treated plots compared with the non-treated plots.
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Simmons, Jason. "Influence of Poultry Litter on Dark Tobacco Growth and Soil Nutrient Availability." TopSCHOLAR®, 2004. http://digitalcommons.wku.edu/theses/516.
Full textAbstract:
Due to the relatively high value of dark tobacco compared with fertilizer costs, nitrogen is recommended at levels as high as 338 kg ha"1. Such rates of inorganic fertilizers increase the osmotic pressure of the soil solution and soil acidity, often causing reduced stands, Mn toxicity, Mo and Ca deficiencies, and reduced yield and quality of the cured leaf (Sims et al., 1984). Poultry litter utilized as a nutrient source is an inexpensive alternative to this dilemma due to its relatively neutral or alkaline composition. However, due the amount of chloride present in poultry litter, the University of Kentucky advises that application be limited to a maximum of 9 Mg ha"1 (Wells, 1996). Environmental concerns such as nitrate contamination of groundwater, P runoff into surface water, and accumulation of heavy metals in the soil are often related to excessive application of poultry litter. Studies were conducted at Western Kentucky University's Agricultural Research and Education Complex in Bowling Green, Kentucky and a farm in Owensboro, Kentucky to evaluate the influence of poultry litter on dark tobacco growth and soil nutrient concentrations. Results from these studies indicate that when applied at recommended rates, poultry litter in most cases can alleviate soil acidification often associated with the use of inorganic fertilizer sources. In general, poultry litter amendments increased soil pH, while inorganic fertilizers had the opposite effect. Data from the Rate Study suggests that rate of inorganic fertilizer and soil pH are negatively correlated. Due to the high nutrient content of poultry litter, its utilization could possibly lead to an accumulation of P2O5 and certain heavy metals, such as Cu and Zn. Data from the Bowling Green Timing Study indicated that poultry litter amendments increased postharvest soil P availability compared to inorganic fertilizer amendments. At the Owensboro location there were no differences in soil P availability among treatments. Results from the Rate Study suggest that soil P availability and poultry litter rate were positively correlated. Data from all studies indicate that in some cases, soil Cu availability was greater in poultry litter treated plots than in plots treated with inorganic fertilizers. With one exception, plots receiving poultry litter were higher in soil Zn availability than inorganic fertilizer plots at the Bowling Green Timing Study. Data from the Rate Study suggests that increasing the poultry litter rate increased soil Zn availability in poultry litter plots receiving a sidedress application. Data from the Owensboro Timing Study indicated that regardless of application timing, cured lamina tissue chloride concentration in poultry litter amended plots were greater than the tobacco industry standard of 1%. Chloride concentrations in the lamina and stem were higher in plots receiving poultry litter than plots treated with inorganic fertilizers. Despite these concentrations there were no noticeable differences in curing and USDA quality rating. Data from the Timing Studies indicated that total yields were equivalent in poultry litter and inorganic fertilizer treated plots, however yields of certain grades did vary. Plots receiving a source of fertilizer had higher total yields than the untreated control. Results from the Rate Study showed that total yields were quite variable, which may be attributed to poor water drainage from the study area. In the Rate Study, a general trend emerged in which increasing the rate of poultry litter in combination with a sidedress application increased trash, lug, and total yield, but decreased tip yield.
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Claycomb, David. "An Economic Study of the Relative Profitability of Alfalfa Production and Marketing Practices." TopSCHOLAR®, 1995. http://digitalcommons.wku.edu/theses/903.
Full textAbstract:
The seasonality of the price of alfalfa hay in Kentucky was studied as well as the potential cost or profitability of storage of this hay. Economic comparison of alfalfa hay production to other farm enterprises was carried out. In addition, an estimate of the value of two qualities of alfalfa hay was calculated based on 1991 prices. The analysis of 41 years of marketing data demonstrated significant differences (P<.01) in price with seasonal lows in June/July and a steady increase in price to a high in March. In general (based on $100 per ton hay and 12% interest) the alfalfa hay producer could lose from $5 to $10 storing hay and selling at a later date. There were some specific conditions where he might have realized a return to storage of $0.16 to $1.48 per ton. A further evaluation of average (KY Feeder) and good (KY Pride) quality hays indicated that current prices of $70-$75 and $100 per ton respectively were the prices where a dairyman would be able to include this hay in the cow's total diet. Even with problems of quality and quantity of alfalfa hay, the economic returns to the production of alfalfa hay were favorable when compared to other crops in Kentucky with the additional benefit of alfalfa being a crop that can result in reduced soil erosion from sloping land. Returns above variable costs can be from $120 to $400 per acre depending upon yield and sale price. However, an understanding of seasonality of price as well as storage costs need to be considered by alfalfa hay producers to assure realizing the above returns.
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Fenton, Lynda L. "Evapotranspiration of Kentucky Bluegrass." DigitalCommons@USU, 2010. https://digitalcommons.usu.edu/etd/745.
Full textAbstract:
Rapid population growth in arid regions of the western US is placing increased demand on water resources. Variability in precipitation and common occurrence of drought have promoted scrutiny of water use in urban lawns and gardens. However, few reliable measurements of water use of these landscapes exist. Quantifying the amount of water used vs. required by landscapes such as turfgrass would allow significant water conservation. Evapotranspiration (ET) is affected by biophysical factors such as: available energy, turbulent mixing, saturation deficit, soil water, and stomatal conductance. In order to simulate the water use by turfgrass, the relative importance of these processes must be determined for this environment. This study measures ET rates for Kentucky bluegrass using eddy covariance techniques, to quantify water use under various conditions. The results are combined with a coupled form of the Penman-Monteith Equation to determine which biophysical factors affect the ET rate under various atmospheric conditions, especially the advection of heat and saturation deficit from the regional atmosphere. In addition, changes in ET and other properties of the vegetation were monitored during a period of reduced irrigation or dry-down. These results will help determine the amount of water such landscapes actually need.
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Von, Boeck Walter. "Agronomical behavior of two kinds of swiss chard (Beta vulgaris var. cicla L.) fertilized with earthworm humus in an underground greenhouse in Viacha, La Paz." BYU ScholarsArchive, 2000. https://scholarsarchive.byu.edu/etd/5452.
Full textAbstract:
The objective of the following work was to evaluate the agronomical behavior of two kinds of Swiss chard fertilized with earthworm humus, and at the same time to know the yield and the costs of production. This work was done in the community of Letanias, located 32 km. from the Department of La Paz and at an altitude of 3860 meters above sea level. Two kinds of Swiss chard were used in this work, Fordhook Giant and Petoseed C003. The three doses of earthworm humus, used as fertilizers, were a2, a3, and a4. The quantity of fertilizer used was 1314, 3560, and 5806 kg per acre, respectively. The Swiss chard was cultivated in a moderate environment, which was in an underground greenhouse with a depth of 1.80 meters. This was so due to the better thermal conditions. Fordhook Giant was the kind that had the best agronomical behavior, reaching an average size of 47.6 cm. for the length of the leaves. From the three levels of Factor A in study, level a3 had the best yield giving an average of 18.1 kg/m^2 of green matter, to which a dosage of 3438 kg. of earthworm humus was applied per acre. The length of the leaves reached an average size of 51.3 cm. The protein content in the Swiss chard leaves increased due to the application of earthworm humus to the ground, thus improving their nutritional quality. The physical and especially the chemical properties were affected positively by the incorporation of earthworm humus. The B/C economic analysis shows that when the earthworm humus is used, the net benefits increase, therefore the farmer family will have a higher income which will help them improve their quality of life.
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Whitacre, Marina K. "Cattle as Grazing Management and Seed Dispersal Tools for Increasing Native Species Diversity on Great Basin Rangelands." DigitalCommons@USU, 2004. https://digitalcommons.usu.edu/etd/6604.
Full textAbstract:
A series of experiments evaluated: 1) the influence of seed intake and gut
retention time on seed passage , recovery , and germinability; 2) fecal seeding and
broadcast /trampling as techniques to incorporate seeds into a well-established
Agropyron desertorum (Fisch.) Schult. stand in Skull Valley , Utah; 3) intensive
grazing as a means to reduce Agropyron biomass and increase establishment and
survival of seeded species; and 4) the recovery and germinability of seed extracted
from dung collected from the field. Two shrubs (Artemisia tridentata Nutt. ssp.
wyomingensis Beetle & Young and Atriplex confertifolia Torr. & Frem.), a grass
(Elymus elymoides (Raf.) Swezey) , and a forb (Sphaeralcea grossulariaefolia (H. &
A.) Rydb.) were selected as representative native species. Holstein heifers were fed
15,000 , 30 ,000 , and 60,000 seeds of Artemisia , Sphaeralcea, and Elymus. Elymus
recovery was negatively correlated to seed intake. Sphaeralcea had the highest
percentage of recovered, undamaged seed, followed by Elymus and Artemisia.
Sphaeralcea and Artemisia seed passage was highest on Day 1 then dropped sharply.
Elymus passage and recovery were more consistent through time. Post-passage
germjnability was highest for Elymus and Sphaeralcea on Day 1. Artemisia
germjnation was neghgible.
In the fall seeding, Sphaeralcea emerged in 6% of the subplots (half were
volunteers). Overall seedling mortality was 93%. Elymus emerged in 63% of the
dung pats, with 86% mortality. No Artemisia emerged. Drought and Anabrus
simplex herbivory contributed to low seedling emergence and survival. In April
2003, similar treatments were applied, except Atriplex seed was substituted for
Artemisia, and a third treatment was added (broadcast seeding/raking). No
emergence was observed. Sphaeralcea had the highest seed recovery from dung
collected in the field trials, followed by Elymus, Atriplex, and Artemisia.
Sphaeralcea germinability was similar for seeds collected from both trials (11 %) and
Elymus germination was highest in the fall seeding (13%).
These studies indicate that: 1) physical seed properties (size, shape, density,
seed coat) influence seed passage , recovery, and germination; 2) intensive grazing
can reduce Agropyron biomass by 50% for 2 years; 3) broadcast/trampling may be
effective for Sphaeralcea; and 4) an average-sized dung pat (714 g) may have ample
germinable Sphaeralcea and Elymus seeds for plant establishment.
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Boglaienko, Daria. "Buckwheat as a Cover Crop in Florida: Mycorrhizal Status, Soil Analysis, and Economic Assessment." FIU Digital Commons, 2013. http://digitalcommons.fiu.edu/etd/921.
Full textAbstract:
This thesis analyses buckwheat as a cover crop in Florida. The study was designed to demonstrate: soil enrichment with nutrients, mycorrhizal arbuscular fungi interactions, growth in different soil types, temperature limitations in Florida, and economic benefits for farmers. Buckwheat was planted at the FIU organic garden (Miami, FL) in early November and harvested in middle December. After incorporation of buckwheat residues, soil analyses indicated the ability of buckwheat to enrich soil with major nutrients, in particular, phosphorus. Symbiosis with arbuscular mycorrhizal fungi increased inorganic phosphorus uptake and plant growth. Regression analysis on aboveground buckwheat biomass weight and soil characteristics showed that high soil pH was the major limiting factor that affected buckwheat growth. Spatial analysis illustrated that buckwheat could be planted in South Florida throughout the year but might not be planted in North and Central Florida in winter. An economic assessment proved buckwheat to be a profitable cover crop.
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Titolo, Donato. "USING AN ACTIVE OPTICAL SENSOR TO IMPROVE NITROGEN MANAGEMENT IN CORN PRODUCTION." UKnowledge, 2012. http://uknowledge.uky.edu/pss_etds/11.
Full textAbstract:
Corn nitrogen (N) applications are still done on a field basis in Kentucky, according to previous crop, soil tillage management and soil drainage. Soil tests, as well as plant analysis for N, are not very useful in making N fertilizer rate recommendations for corn. Recommended rates assume that only 1/3 to 2/3 of applied N is recovered, variability largely due to the strong affect of weather on the release of soil N and fertilizer N fate. Many attempts have been made to apply N in a more precise and efficient way. Two experiments were conducted at Spindeltop, the University of Kentucky’s experimental farm near Lexington, over two years (2010, 2011), using a commercially available active optical sensor (GreanSeekerTM) to compute the normalized difference vegetative index (NDVI), and with this tool/index assess the possibility of early (V4-V6) N deficiency detection, grain yield prediction by NDVI with and without side-dressed N, and determination of the confounding effect of soil background on NDVI measurements. Results indicated that the imposed treatments affected grain yield, leaf N, grain N and grain N removal. Early N deficiency detection was possible with NDVI. The NDVI value tended to saturate in grain yield prediction models. The NDVI was affected by tillage management (residue/soil color background differences), which should be taken into account when using NDVI to predict grain yield. Side-dress N affected NDVI readings taken one week after side-dressing, reducing soil N variability and plant N nutrition. There is room for improvement in the use of this tool in corn N management.
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Hambrick, Timothy. "Effect of Phosphorus Placement Methods on the Yield & Quality of Tomatoes." TopSCHOLAR®, 1989. https://digitalcommons.wku.edu/theses/2422.
Full textAbstract:
Research was undertaken in the summer and fall of 1988 to determine the effect of phosphorus placed below, below and to the side, banded and incorporated, and broadcast on the yield and quality of tomatoes.
The results of the field study were not statistically significant due to high levels of available soil phosphorus. However, there were trends toward higher total yields, higher yield of number one grade tomatoes, and higher tissue phosphorus levels when phosphorus was placed in a concentrated zone or band as contrasted with the more popular broadcast method.
The effect of phosphorus placement in the greenhouse was studied using two different soils, a high available phosphorus soil and a low available phosphorus soil. Again, phosphorus placed in a concentrated zone produced plants with higher tissue phosphorus levels, regardless of the soil the plants were grown on.
31
Sandifer, G. Tom Jr. "The Effect of Tillage Methods & Row-Widths on Selected Growth Characteristics & Yield of Soybeans." TopSCHOLAR®, 1985. https://digitalcommons.wku.edu/theses/2811.
Full textAbstract:
The effect of three tillage methods confounded with three row widths on root length and depth, seed density, seeds per pod, pods per plant and yield of Glycine max was studied during the 1984 growing season. The study was conducted on class 1, Pembroke soil located in south Warren County, Kentucky. A barley crop was removed from the area just prior to the experimental plantings. A John Deere conservation tillage, plateless planter was used in all experimental treatments except the drilled plots. Plant populations were adjusted to conform to standard recommendations for drill (7 inch row widths), 15-inch row widths, and 30-inch row widths. Tillage methods were no-till (soybeans were seeded directly into barley stubble), conventional (the land was chisel plowed to a depth of 8 to 10 inches and then disced twice to a depth of four inches prior to planting), and ro-till (the ro-till machine prepared a 10 inch wide seed bed directly into barley stubble by utilizing a deep chisel preset to reach a depth of ten inches, four large disks preset to run at a depth of approximately six inches followed by a rolling steel basket designed to level the seed bed and macerate large particles of soil). All experimental plots were planted within a six hour time span.
The eight row width by tillage method treatments were fifteen inch no-till (15N), thirty inch no-till (30N), fifteen inch conventional (15C), thirty inch conventional (30N), fifteen inch ro-till (15R), thirty inch ro-till (30R), drill conventional (DC), and drill ro-till (DR).
Treatments were arranged in a randomized complete block design replicated six times. Each block contained all treatments arranged in a random fashion to reduce error due to side-row variation.
Root length and depth determinations were made at the crook, unifoliate, first trifoliate, third trifoliate, and fifth trifoliate stages of development. Seed density, seeds per pod, pods per plant, and yield were studied at physiological maturity. Rainfall was recorded daily throughout the growing season.
Results showed significant differences in root length, root depth, seed density, and yield; but no significant differences were found in seeds per pod or pods per plant. The ro-till tillage method improved root development (depth and length) over the conventional and no-till tillage method; however, yield data was not greatly affected by this improvement. Yield was seemingly affected most by row-width differences with drilled rows and 15-inch rows ranking above 30-inch rows in production.
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Thompson, Christopher. "The Effect of Phosphorous Placement & Rate on Phosphorus Uptake, & Growth & Yield of Tomatoes." TopSCHOLAR®, 1990. https://digitalcommons.wku.edu/theses/2931.
Full textAbstract:
Research was undertaken in the summer of 1989 to determine the effect of phosphorus placement on the yield and quality of field grown tomatoes Lycopersicon esculentum. A subsequent study was undertaken in the winter of 1989 to determine the effect of phosphorus rate and placement on the early growth and phosphorus uptake of young tomatoes in the greenhouse.
The purpose of this study was to attempt to find the most efficient placement and rate of supplemental phosphorus when growing tomatoes. It has been shown that placing phosphorus in a concentrated zone in contact with plant roots results in more growth and fruit yield. The current trial involved the application of phosphorus at different rates and use of different methods of application. The methods of application included broadcasting phosphorus, placing phosphorus in a concentrated band, and combinations of the two.
It is of great interest to the tomato producer to know the most efficient rate and placement of fertilizer phosphorus. Availability of phosphorus is necessary for the proper development of the tomato and a good supply is needed for adequate yield and quality. If improved application methods are developed, perhaps higher yields and improved fruit quality can be realized. This could possibly result in higher production for the producer and more satisfaction for consumers.
The results of the field study were not statistically significant. One reason for the lack of any yield response was the greatly reduced yields caused by hail damage and fungal disease.
Surprisingly, the greenhouse study showed that significant growth increase resulted from phosphorus broadcast treatments. One explanation may be the small volume of soil used in this study. The plant roots were distributed throughout the entire soil volume in contrast to the situation with widely spaced field grown tomatoes. Thus, the broadcast treatments achieved more root-fertilizer contact in the greenhouse pot cultures.
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Widodo. "The Effects of Spacings & Cultivars on Biological Yields, Yields, Component of Yield & Harvest Index of Green Bush Snap Bean (Phaseolus vulgaris L.)." TopSCHOLAR®, 1989. https://digitalcommons.wku.edu/theses/2967.
Full textAbstract:
The effects of cultivars and plant spacings on biological yield, seed yield, seeds per pod, average seed weight, and harvest index of beans (Phaseolus vulgaris L.) were studied in 1987 and 1988. Two cultivars, 'Blue Lake 27' and 'Kentucky Wonder 125' and four plant spacings -- 7, 14, 21, and 28 cm, constituted eight treatments that were arranged in a split-plot with four replications. Each experimental unit or hill consisted of five plants -- four in the corners and one in the center of a square. Spacings treatment were established by varying the distance between the center plant and the four corner plants. Corner plants provided competition; only the center plant was harvested for experimental data. The data were subjected to analysis of variance procedure for a split-plot design, assuming a fixed model.
The cultivars had similar biological yield curves during the 1987 growing season and did not differ significantly for biological yield at the final harvest either year. Kentucky Wonder 125 produced significantly higher average seed weight and harvest index, but fewer seeds per pod, than did Blue Lake 274. In 1987, seed yield per plant was higher for Blue Lake 274 than for Kentucky Wonder 125; however, the cultivars did not differ significantly for seed yield per plant in 1988.
Spacing treatment effects were not significant when expressed through seed yield per plant, seeds per pod, average seed weight, or harvest index. Spacings affected biological yield significantly in 1988, but not in 1987. The linear response of biological yield to spacing was positive and significant both years. The linear effect of spacings on pod yield was significant in 1988, but not in 1987.
Drought conditions in 1987 and 1988 adversely affected bean growth and seed production. The experimental error, as evidenced by large coefficients of variation for treatment means, was unusually high. Consequently, some true cultivar and spacing effects may not have been detected.
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Shelton, Rebecca Erin. "CONSERVATION AGRICULTURE IN KENTUCKY: INVESTIGATING NITROGEN LOSS AND DYNAMICS IN CORN SYSTEMS FOLLOWING WHEAT AND HAIRY VETCH COVER CROPS." UKnowledge, 2015. http://uknowledge.uky.edu/pss_etds/59.
Full textAbstract:
Unintentional nitrogen (N) loss from agroecosystems produces greenhouse gases, induces eutrophication, and is costly for farmers; therefore, adoption of conservation agricultural management practices, such as no-till and cover cropping, has increased. This study assessed N loss via leaching, NH3 volatilization, N2O emissions, and N retention in plant and soil pools of corn conservation agroecosystems across a year. Three systems were evaluated: 1) an unfertilized organic system with cover crops Vicia villosa, Triticum aestivum, or a mix of the two; 2) an organic system with a Vicia cover crop employing three fertilization schemes (0 N, organic N, or a cover crop N-credit approach); 3) a conventional system with a Triticum cover crop and three fertilization techniques (0 N, urea N, or organic N). During cover crop growth, species affected N leaching but gaseous emissions were low across all treatments. During corn growth, cover crop and fertilizer approach affected N loss. Fertilized treatments had greater N loss than unfertilized treatments, and fertilizer type affected gaseous fluxes temporally and in magnitude. Overall, increased N availability did not always indicate greater N loss or yield, suggesting that N conserving management techniques can be employed in conservation agriculture systems without sacrificing yield.
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Law, Audrey. "EVALUATING THE EFFECTS OF ORGANIC AND CONVENTIONAL INPUTS ON SOIL CHEMICAL AND BIOLOGICAL PROPERTIES IN A FOUR-YEAR VEGETABLE ROTATION AND THE INVESTIGATION OF SOIL MICROBIAL PROPERTIES ON PLANT GENE EXPRESSION." UKnowledge, 2009. http://uknowledge.uky.edu/gradschool_diss/704.
Full textAbstract:
The objective of this research was to determine the effects of conventional inputs on soil chemical and biological properties compared to organic systems in a four year vegetable rotation. Tillage and cover crops were the same in all treatments to avoid confounding factors often present in similar research. Additional experiments investigated plant gene expression in organic and conventional management systems and in soils with decreased microbial diversity. Experimental plots were prepared in the spring of 2004; four replications of three management treatments, organic, low-input and conventional, were arranged in a randomized complete block design. The rotation consisted of edamame soybean, sweet corn, fallow (pastured poultry in organic plots), and potatoes. Soil samples were taken in the spring and fall of each year, along with data for pest damage, weed control, yield and quality. Soil samples were analyzed for enzyme activity (maximum activity under substrate saturation) and basic soil chemical properties. Treatments were compared over time using 2-Way ANOVA. Multiplex terminal-restriction fragment length polymorphism (M-TRFLP) profiles of the soil microbial community were compared using Multiple Response Permutation Procedures (MRPP). Multi-way ANOVA detected significant treatment effects over time in total carbon, nitrogen, Mehlich III K, Exchangeable K and exchangeable Na (p=0.05). Many significant changes in soil properties over time could not be attributed to treatment effects. All treatments produced similar yields, indicating that successful organic production of these vegetables is possible in Kentucky. Input costs for organic were 37% higher than conventional, due to the cost of organic fertilizer. The organic system required nearly 50% more labor hours than conventional or low-input. The low-input system was the most cost effective, with 58% less input expenses than the conventional system. Microarray analysis of approximately 37,500 Glycine max transcripts did not show significant differences in the gene expression between plants grown organically and conventionally, in plots with significant soil chemical and microbial differences. An experiment in progress is investigating changes in plant gene expression using real time RT-PCR in tomatoes grown in autoclaved soil and native field soil.
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Jimenez, Ricardo A. "Evaluation of Fomesafen for Broadleaf Weed Control, In Soybeans (Glycine Max)." TopSCHOLAR®, 1988. http://digitalcommons.wku.edu/theses/1711.
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The lack of effective broadleaf weed control represents one of the major factors having detrimental effects on growth and yield of soybeans. Broadleaf weeds are a serious threat to soybean growers in the southeastern United States. A broad range of herbicides is being used in an effort to control broadleaf weeds in soybeans, and research is still being conducted to find new herbicides that can best work for this purpose. This study involved the use of one these herbicides. It was fomesafen, 5-[2-chloro-4-trifluromethyl) phenoxy]-N-(methyl-sulfonyl)-2-nitrobenzamide, which controls a broad spectrum of broadleaf weeds in soybeans.
The experiment was conducted in the summers of 1987 and 1988. Broadleaf weed control treatments with fomesafen at rates at 0.07, 0.14, 0.28, and 0.35 kg ai/ha in single early postemergence and late postemergence applications were evaluated using the herbicide with a nonionic surfactant at 0.25% and 0.50% of the solution. All treatments were compared with a check which did not receive herbicide application. Among the most common broadleaf weeds found in the area under study during the summer of 1987 were morningglories (Ipomoea spp), redroot pigweed (Amaranthus retroflexus L.), jimsonweed (Datura stramonium L.), common lambsquarters (Chenopodium album L.), carpetweed (Moliugo verticillata L.), and prickly sida (Sida spinose L.), For the summer of 1988 the most prevalent broadleaf weeds were morningglories, horsenettle (Solanum carolinense L.), horseweed [Conyza canadensis (L.), Cronq.], and prickly sida.
The results of the experiment showed no significant differences between early postemergence and late postemergence treatments. There were no significant differences in broadleaf weed control in treatments which received 0.14, 0.28 and 0.35 kg ai/ha of fomesafen for either 1987 or 1988. Poor broadleaf weed control resulted with the application of fomesafen at its lowest rate (0.07 kg ai/ha). No significant differences were found in broadleaf weed control between concentration of 0.25% and 0.50% of the nonionic surfactant added to fomesafen.
Statistically significant yield variation did occur among treatments in 1987. No significant differences in yields were found between any of the herbicide treatments in 1988. Soybean yields were significantly higher in 1988 than in 1987.
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Mairs, Ryan Alan. "Effects of Bacillus Mycoides Supplement in a Reduced Frequency Fungicide Program on Chambourcin Grapevines (Vitis Vinifera L.)." TopSCHOLAR®, 2018. https://digitalcommons.wku.edu/theses/3047.
Full textAbstract:
Fungal diseases pose significant challenges for grapevine producers in Kentucky due to the region’s abundant moisture and relative humidity. Methods to reduce fungicide application frequency would prove both economically and temporally valuable to producers. A field experiment was established in Bowling Green, KY in 2017 to investigate Bacillus mycoides isolate J (LifeGard) as a supplement to a fungicide program for systemic acquired resistance (SAR). Three fungicide treatment regimens were implemented consisting of a program modelled from the Midwest Fruit Pest Management Guide (2017) and an identical program supplemented with 140 g ha-1 LifeGard per application (both applied on 14 day intervals), a reduced frequency application every 28 days supplemented with 140 g ha-1 LifeGard, and an untreated control. Treatments were applied to 9-year-old French-Hybrid grapevines (cv. Chambourcin); each treatment was replicated 3 times in a randomized complete block design. All treatments were applied with a backpack sprayer delivering 150 L ha-1 at 2 Bar pressure. Canopy management, fertility, herbicide, and insect management were standardized across treatments and no supplemental irrigation was applied. Data collected included fruit yield, pH, ºBrix, and titratable acidity (TA). Data were analyzed with SAS PROC GLIMMIX; differences in means were determined at < 0.05. Plots supplemented with B. mycoides had lower fruit pH than untreated plots but higher fruit pH than the traditional fungicide program. Treatment regime did not influence Brix, TA, or total yield; however, all treated plots yielded more high quality fruit than the untreated control.
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Dye, Rick. "Isolation & Characterization of a Type I Topoisomerase from the Hypocotyls of Etiolated Soybeans." TopSCHOLAR®, 1989. https://digitalcommons.wku.edu/theses/2278.
Full textAbstract:
Topoisomerases are enzymes of critical biological significance. Despite this fact, little data specific to the topoisomerases of higher plants has been published. This research was undertaken to isolate and characterize a higher plant topoisomerase from soybean hypocotyls to further the understanding of the structure and function of these enzymes.
Nuclei were isolated from frozen hypocotyls of 4 day old etiolated soybeans by homogenization and centrifugation, then lysed by gentle stirring in the presence of 1.5 mM ammonium sulfate. The resultant extract was desalted and purified by column chromatography on DEAF sepharose, 5-200 sephacryl and CM cellulose. The components of the purified fraction were separated by electrophoresis on non-denaturing polyacrylamide and recovered by electro-elution.
The molecular weight of the native enzyme was determined to be 225 kilodaltons (Kd) by gel filtration and 300 Kd by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Three smaller molecular sub-species, possibly resulting from dissociation of the native enzyme in the presence of beta mercaptoethanol (BME), were isolated. These smaller molecules had approximate molecular weights of 155 Kd, 29 Kd and 25 Kd. The two smaller polypeptides appeared to re-associate to form a 68 Kd aggregate in the absence of BME. This aggregate was subsequently resistant to denaturation by sodium dodecyl sulfate (SDS).
The purified native enzyme was found to be adenosine triphosphate (ATP) and Mg++ (divalent magnesium ion) independent. Although not required, the presence of magnesium (Mg) stimulated enzyme activity. Manganese (Mn++) stimulated activity to a lesser degree. Enzymatic activity was inhibited by ATP, potassium chloride (KC1) and N-ethylmaleimide (NEM) but not inhibited by novobiocin.
The results indicate that a type I topoisomerase was purified from the nuclei of soybeans (Glycine max). The soybean topoisomerase I has a native molecular weight similar to that of cauliflower (200 Kd) and like cauliflower topoisomerase was inhibited by NEM but not by novobiocin and was stimulated by Mg++. It is similar to vaccinia virus topoisomerase I in being slightly inhibited by ATP. The data suggests that the native enzyme may be composed of enzymatically active domains as small as 27 Kd and thus is similar to vaccinia virus and Ustilaqo maydis topoisomerase I.
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Baniszewski, Julie. "IRRIGATED ZEA MAYS RESPONSE TO NITROGEN AND HIGH PLANT POPULATION DENSITY IN NARROW ROWS." UKnowledge, 2016. http://uknowledge.uky.edu/pss_etds/73.
Full textAbstract:
Modern genetics have improved maize hybrids to better tolerate stress, use nutrients more efficiently and potentially yield higher. Management practices, such as narrow row technology and high plant population density (PPD) may further improve yields in modern maize under irrigated, non-limiting conditions. High PPD (74, 99, 124, 148 K seeds ha-1) were tested in narrow rows with up to four nitrogen (N) rates in three locations over two years in Kentucky with a modern maize hybrid in irrigated, non-limiting conditions. Results indicate that optimal seeding rates were 99,000 to 124,000 seeds ha-1, providing maximum yield and highest partial return, likely due to increasing seed number ha-1 and greater canopy closure, although seed size declined and pollination was more asynchronous as PPD increased. Excess N did not overcome silking delay or the decline in kernel mass associated with higher PPD, indicating 252 kg N ha-1 was adequate for high yields at any population, although data indicates better utilization of supplied N at higher populations. Implications can be used to implement better management techniques in high-yielding maize to supplement use of improved genetics.
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Ferrufino, Miranda José. "Evaluation of quinoa (Chenopodium quinoa Willd) at different spacings between furrows and plants in the Mamani community." BYU ScholarsArchive, 2003. https://scholarsarchive.byu.edu/etd/5360.
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This study addressed spacing between furrows and plants in the cultivation of the quinoa variety Patacamaya. This study took place from 1999 to 2000 in the Mamani community, Ingavi, La Paz, Bolivia. The Patacamaya variety is a cross between Samaranti (sweet) and Kaslala (bitter), with a vegetative cycle of 145 days (semi-early). It has large grains, is sweet, and has a high grain yield. The spaces between furrows were 40, 60, and 80 cm in an experimental design of randomly divided plots with four repetitions. The spaces between furrows were implemented in large plots and the plant spaces as sub-treatments in small plots. The results showed that the height of the plants were similar in all treatments except for T1 that was 35% lower compared with the other treatments. The highest grain yields occurred in treatment T6 with a value of 2,708.5 kg/ha, followed by T1 and T11. The lowest grain yields occurred in treatments T15, T10, and T5 with values of 1,124.3, 1561.4, and 1653.3 kg/ha, respectively.
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Pablo, Raúl Andrade Andrade. "Effect of chemical fertilization and organic amaranth (Amaranthus caudatus L.) var. Alegria INIAP Chaltura." BYU ScholarsArchive, 2006. https://scholarsarchive.byu.edu/etd/5414.
Full textAbstract:
The present investigation was made in the Experimental Farm "La Pradera", located in the province of Imbabura, the parish of San José de Chaltura, to 1350 meters above sea level and an average temperature of 16, 4⁰ C. To analyze the effect of the chemical and organic fertilization in amaranth of variety INIAP "Alegría" was the primary target of the investigation. The field work was made in a lapse of 6 months. The design of complete blocks (DBCA) with 15 treatments was used at random and three repetitions by treatment. The experimental unit was 18 m². It was evaluated by means of analysis of variance and the Turkey test at 5%. The factors in this study are constituted by the elements N, P, S and organic fertilizer. The analyzed variables were: number of plants; days to the flowering; days to the harvest; height of plants; biomass; extraction of nutrients; and grain yield. The number of plants presented significant difference to 1% for treatments and to 5% for blocks, the treatments that reached the greater number of plants are T11 (80-60-40-0) and T14 (0-0-0-10) with an average of 30 and 29 plants of amaranth in 0.50 linear m respectively. The treatment T4 (120-60-20-0) presented the greater height at 45 days of seedtime, with an average of 24.10 cm. The height of plants at flowering I present significant statistical results highly is the T4 (120-60-20-0) and T5 (160-60-20-0) respectively present values of height of 119.30 and 103.40 centimeters. The height of plants at the harvest determines significant difference for treatments the highest being the T5 (160-60-20-0), the one that reached the greatest height with an average of 148, 11 centimeters. The days to the flowering of the amaranth were between 70 and 85 days from seedtime and the days to the harvest were between 143 and 152 days. The treatment that reached the greater mean efficiency was the T5 (160-60-20-0) with 2583, 69 Kg/ha unlike the control who reached an average of yield of 686, 66 Kg/ha. In the organic treatments the greater yield registry in T15 (0-0-0-15) where 15 tons of organic fertilizer by hectare was used resulting in 1672.59 Kg/ha.
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Santoro, Maria Julia. "CORN GRAIN YIELD COMPONENTS AND NUTRIENT ACCUMULATION IN RESPONSE TO NITROGEN, PLANT DENSITY AND HYBRID." UKnowledge, 2018. https://uknowledge.uky.edu/pss_etds/100.
Full textAbstract:
Modern maize hybrids exhibit higher yields, increased biomass production, stress tolerance and greater nitrogen (N) use efficiency. Increased biomass accumulation can influence nutrient uptake and lead to increased nutrient removal. Hybrids were tested at seeding rates (SR) of 74000 (low) and 148000 (supraoptimal) plants ha-1 and at N rates of 0 (deficient) and 390 (non-limiting) kg N ha-1. Plants were sampled at V7, V14, R3, R5 and R6 and separated into vegetative and reproductive fractions for determination of dry matter and N accumulation. Grain yield was harvested at R6.
The high SR and high N treatment combination resulted in greatest biomass accumulation, crop growth rates, and N accumulation per hectare in both vegetative and grain tissues.
The high SR and high N combination maximized grain yield at 20.6 Mg ha-1, essentially through an increase in kernels ha-1. High SR decreased kernel weight, even with high N. At the higher plant densities resulting from the high SR, however, average utilization of available N was enhanced. The results have implications for improved management practices under high input systems and providing insight to growers who incorporate variable seed and N rates.
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Shahadha, Saadi Sattar. "Measured Soil Hydraulic Properties as RZWQM2 Input to Simulate Soil Water Dynamics and Crop Evapotranspiration." UKnowledge, 2018. https://uknowledge.uky.edu/pss_etds/110.
Full textAbstract:
Agricultural system models integrate many different processes that cannot all be measured in field experiments and help quantify soil water dynamics, crop evapotranspiration, and crop growth with high temporal resolution. Understanding soil water dynamics and crop evapotranspiration is essential to improve agricultural management of field crops. For example, the interaction between nitrogen application rate and water dynamics is not sufficiently understood. In most cases, model simulations deviate from field measurements, especially when model input parameters are indirectly and unspecifically derived. The extent to which measured soil hydraulic property inputs decrease the discrepancy between measured and simulated soil water status is not well understood. Consequently, this study: (i) investigated thr use of measured soil hydraulic properties as Root Zone Water Quality Model (RZWQM2) inputs compared to indirectly derived inputs; (ii) explored the capability of calibrating measured soil hydraulic property input parameters for one crop and using them for other crops without further calibration; (iii) studied the effect of the nitrogen application rate on the behavior of soil water dynamics and crop evapotranspiration using RZWQM2 under different rainfall amounts. To evaluate the model in different field management conditions, a field experiment with soybean, corn, wheat, and fallow soil was conducted from 2015 – 2017 to collect field data to calibrate and validate the RZWQM2 model. The model presented a satisfactory response to using measured soil hydraulic property inputs and a satisfactory capability to quantify the effect of nitrogen rates on daily crop evapotranspiration, soil water dynamics, and crop growth. With sufficient measurements of soil hydraulic parameters, it was possible to build a RZWQM2 model that produced reasonable results even without calibration.
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Sciarresi, Cintia Soledad. "OPTIMIZING COVER CROP ROTATIONS FOR WATER, NITROGEN AND WEED MANAGEMENT." UKnowledge, 2019. https://uknowledge.uky.edu/pss_etds/122.
Full textAbstract:
Winter cover crops grown in rotation with grain crops can be an efficient integrated pest management tool (IPM). However, cover crop biomass production and thus successful provisioning of ecosystem services depend on a timely planting and cover crop establishment after harvest of a cash crop in the fall. One potential management adaptation is the use of short-season soybeans to advance cover crop planting date in the fall. Cover crops planted earlier in the fall may provide a greater percentage of ground cover early in the season because of higher biomass accumulation that may improve weed suppression. However, adapting to short-season soybeans could have a yield penalty compared to full-season soybeans. In addition, it is unclear if further increasing cover crop growing season and biomass production under environmental conditions in Kentucky could limit nitrogen and water availability for the next cash crop. This thesis combines the use of field trials and a crop simulation model to address the research questions posed.
In Chapter 1, field trials evaluating yield and harvest date of soybean maturity group (MG) cultivars from 0 to 4 in 13 site-years across KY, NE, and OH, were used to calibrate and evaluate the DSSAT crop modeling software (v 4.7). The subsequent modeling analysis showed that planting shorter soybean maturity groups (MG) would advance date of harvest maturity (R8) by 6.6 to 11 days per unit decrease in MG for May planting or by 1 to 7.3 days for July planting. The earliest MG cultivar that maximized yield ranged from MG 0 to 3 depending on the location, allowing a winter-killed cover crop to accumulate between 257 to 270 growing degree days (GDD) before the first freeze occurrence when soybean was planted in May, and between 280 to 296 GDD when soybean was planted in July. Winter-hardy cover crops could accumulate 701 to 802 GDD following soybean planted in May and 329 to 416 GDD after soybean planted in July.
In Chapter 2, a two-year field trial was conducted at Lexington, KY to evaluate the effect of a soybean – cover crop rotation with soybean cultivars MG 1, 2, 3 or 4 on cover crop biomass and canopy cover, and on weed biomass in the fall and the following spring. Results showed that having cover crops was an efficient management strategy to reduce weed biomass in the fall and spring compared to no cover treatment. Planting cover crops earlier in the fall after a short-season soybean increased cover crop biomass production and percentage of ground cover in the fall, but not the following spring. Planting cover crop earlier after a short-season soybean did not improve weed suppression in the fall or spring compared to a fallow control with full-season soybean. Having a fall herbicide application improved weed control when there was a high pressure of winter annual weeds. By the spring, delaying cover crop termination increased cover crop biomass but also did weed biomass.
In Chapter 3, a soybean – cover crop – corn rotation was simulated to evaluate the effect of different soybean MG and cover crop termination, as well as year to year variability on water and nitrogen availability for the next corn crop in Lexington, KY. Simulations showed that when cover crops were terminated early, they did not reduced soil available water at corn planting. However, introducing a non-legume cover crop reduced total inorganic nitrogen content in the soil profile by 21 to 34 kg ha-1 implying 15 to 30 kg ha-1 less in corn nitrogen uptake. Cover crop management that was able to maintain similar available water values than fallow treatment while minimizing nitrogen uptake differences was cover crops planted after soybean MG 4 with an early termination. However, the best management strategies that will maximize ecosystem services from cover crops as well as cash crop productivity may need to be tailored to each environment, soil type, irrigation management, and must consider year-to-year variability.
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Florence, Darlene Christina. "Agronomic Land Management Effects on Soil Fertility and Grain Crop Productivity in Western Kenya and Ohio." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1338341162.
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Chater, John Matthew. "THE EFFECTS OF FOLIAR NUTRIENT APPLICATIONS ON SPLIT, YIELD, AND INTERNAL FRUIT QUALITY OF 'WONDERFUL' POMEGRANATE (PUNICA GRANATUM L.)." DigitalCommons@CalPoly, 2015. https://digitalcommons.calpoly.edu/theses/1510.
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Fruit split is the most important physiological disorder in pomegranate production, causing devastating crop losses worldwide. Foliar nutrient applications have been used experimentally to mitigate pomegranate fruit split but none have been conducted using the industry standard cultivar, Wonderful, and little is known about the effects of foliar nutrient applications on pomegranate. Additionally, investigations into putative health benefits of pomegranate fruit have increased interest in its production but limited evidence exists regarding effects of agricultural practices such as foliar fertilizer applications on internal fruit quality. ‘Wonderful’ pomegranate trees at 2 commercial orchards were treated with foliar applications of ZnSO4 (3000 mg∙L-1, 4000 mg∙L-1, or 5000 mg∙L-1), MgSO4 (1%, 2%, or 3%), KNO3 (1%, 2%, or 3%), or deionized (DI) water (control). Fruit were analyzed for fruit split incidence, yield, fruit number per tree, fruit diameter, fruit mass, mass of all arils in fruit, mass of 100 arils, total soluble solids (TSS), titratable acidity (TA), antioxidant activity (AA), total phenolics (TP), and mineral nutrient concentrations of leaves and fruit. Foliar applications of MgSO4 and ZnSO4 resulted in significantly lower fruit split incidence. Treatments had no significant effect on fruit number per tree, fruit diameter, and mass, mass of all arils in fruit, or mass of 100 arils. Leaf N, K, S, Mn, and Zn were significantly affected by the treatments. TSS and TA were not affected significantly by treatments. AA ranged from 77.8-84.3 percent inhibition of 2,2’-diphenyl-1-picrylhydrazyl and TP ranged from 2489-3046 mg·L-1 gallic acid equivalents, with some KNO3 treatments significantly affecting these parameters. Fruit mineral nutrient concentrations were characterized and Zn-treated trees had greater fruit Zn concentrations. The results suggest that foliar ZnSO4 or MgSO4 could be used to decrease fruit split incidence and increase nutritional content of ‘Wonderful’ pomegranate and any of the three tested foliar nutrients could be applied as a foliar fertilizer without negatively impacting fruit yield, size, internal quality, bioactivity, or mineral nutrient concentration.
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Kenney, Ian T. "Regional assessment of short-term impacts of corn stover removal for bioenergy on soil quality and crop production." Thesis, Kansas State University, 2011. http://hdl.handle.net/2097/13186.
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Master of Science<br>Department of Agronomy<br>Humberto Blanco<br>DeAnn Presley<br>The U.S. agricultural sector is in a prime position to provide crop residues such as corn (Zea mays L.) stover as feedstock for large-scale bioenergy production. While producing renewable energy from biomass resources is a worthy initiative, excessive removal of corn stover from agricultural fields has the potential to increase soil erosion, degrade soil properties, and reduce corn yields. A need exists to objectively assess stover removal impacts on agriculture and the environment on regional scales. This project assessed the effects of removing various rates of corn stover on runoff and erosion and changes in soil physical properties and corn yields on a regional scale across three soils at Colby, Hugoton, and Ottawa in Kansas, USA. The soils were Ulysses silt loam (Fine-silty, mixed, superactive, mesic Aridic Haplustolls) at Colby, Hugoton loam (Fine-silty, mixed, superactive, mesic Aridic Argiustolls) at Hugoton, and Woodson silt loam (Fine, smectitic, thermic Abruptic Argiaquolls) at Ottawa, all with slopes [less than or equal to] 1%. Five stover treatments were studied that consisted of removing 0, 25, 50, 75, and 100% of stover after harvest from no-till and strip-till continuous corn plots. Simulated rainfall was applied in spring 2010 at rates representing 5 yr return intervals at each site and included a dry and wet run. Runoff increased with an increase in stover removal at Colby and Hugoton, but not at Ottawa. At Colby, stover removal rates as low as 25% caused runoff to occur 16 min sooner and increased sediment loss. At this site, runoff and sediment-carbon (C) loss increased as removal rates exceeded 25%. At Hugoton, complete stover removal increased loss by total N by 0.34, total P loss by 0.07, PO[subscript]4-P by 0.003 and NO[subscript]3-N by 0.007 kg ha-[superscript]1. At Ottawa, PO[subscript]4-P loss decreased by 0.001 kg ha-[superscript]1 with 25% removal and by 0.003 kg ha-[superscript]1 with 50% removal. Mean weight diameter (MWD) of wet aggregates decreased with an increase in stover removal on all soils. At Ottawa, stover removal at 75% reduced soil C in the top 5 cm by 1.57 Mg ha-[superscript]1. Soil volumetric water content decreased with stover removal at Colby and Ottawa, but was variable at Hugoton. Soil temperature tended to increase with stover removal during summer months and decrease during winter months. Soil temperature also fluctuated much more widely with stover removal, resulting in more freeze-thaw events compared to no stover removal. No effect of stover removal on soil water retention was observed on any of the soils. In 2009, removal rates [greater than or equal to]50% resulted in greater grain yield at Colby, while removal rates [greater than or equal to]75% resulted in greater grain yields at Ottawa in 2009 and 2010. Results from the first two years of stover management suggest that stover removal at rates above 25% for bioenergy production increased water erosion, degraded soil structural properties, and altered soil water and temperature regimes. Higher rates of removal ([greater than or equal to]75%) can also reduce soil C concentration in the short-term in rainfed regions. However, grain yields may be enhanced by stover removal from irrigated soils and from rainfed soils with adequate moisture. Overall, the increase in water erosion and alteration in soil properties in the short-term suggest that stover removal can detrimentally affect water quality and soil productivity in Kansas. Further long-term monitoring is warranted to conclusively discern stover removal implications.
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Miranda, Fernandez Saul Victor. "Processing and Conservation of the Little Corn in Aiquile province in the Cochabamba Department: use of antioxidants, organic and industrial evaluation." BYU ScholarsArchive, 1997. https://scholarsarchive.byu.edu/etd/5402.
Full textAbstract:
The present work was conducted in order to determine an adequate variety in the processing of small corn, in which a monitoring of all the cycle in cultivation was conducted. The behavior of the small corn was analyzed in the laboratory before the presence of three antioxidants, ascorbic acid, acetic acid and sodium sulfate in two concentrations in addition to subjecting them to thermal treatments that allows us to obtain a pleasant product for the consumer that is both resistant to treatment and nutritious for the health. The results indicate that the best variety of corn is muruchi yellow, the most effective antioxidant is sodium sulfate with a concentration of 1% and the thermal treatment of 10 minutes which obtained the best results, being most pleasing to those persons that evaluated the corn for its organic qualities followed by the ascorbic and acetic acid provided which provided a project of industrial feasibility that provides the information as a convenience to investment.
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Pyzola, Stephanie. "NITRATE REDUCTION COUPLED TO IRON(II) AND MANGANESE(II) OXIDATION IN AN AGRICULTURAL SOIL." UKnowledge, 2013. http://uknowledge.uky.edu/pss_etds/20.
Full textAbstract:
New evidence shows iron(II) oxidation is strongly coupled to nitrate reduction under anaerobic conditions in freshwater sediments and agricultural soils. However, the contribution of iron(II) oxidation to nitrate reduction is unknown. Furthermore, oxidation of manganese(II) by nitrate has been largely overlooked. This study investigated nitrate-dependent iron(II) and manganese(II) oxidation in an agricultural soil (Sadler silt loam) using stirred-batch kinetic techniques with native soil organic carbon (SOC) as the electron donor and included addition of amendments (hydrogen gas and wheat residue). In the presence of native SOC, nitrate-dependent Fe(II) and Mn(II) oxidation occurred at early stages of the reaction while organic carbon participated at longer times. Contributions of iron(II) and manganese(II) oxidation to nitrate reduction were 19% and 25%, respectively. This is significant in light of excess SOC relative to total Fe and Mn in the Sadler soil. Addition of hydrogen gas lowered the contribution of iron(II) oxidation to nitrate reduction to 10%, while addition of plant residue raised this value to approximately 55%. Manganese(II) oxidation contributed 50% to nitrate reduction under hydrogen amended conditions. These coupled processes involving Fe(II) and Mn(II) oxidation are an underappreciated aspect of the nitrogen cycle and merit consideration in future studies.
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Sherman, Austin. "INTEGRATING COVER CROPS AND HERBICIDES FOR HORSEWEED [Conyza canadensis (L.) Cronq.] MANAGEMENT PRIOR TO SOYBEAN [Glycine max (L.) Merr.]." UKnowledge, 2019. https://uknowledge.uky.edu/pss_etds/121.
Full textAbstract:
Horseweed (Conyza canadensis (L.) Cronq.) is prevalent in Kentucky and can be difficult to control. Research has shown multiple weed control methods to be more sustainable than relying on chemical control alone, so the use of multiple methods for horseweed management was examined in this study. The main objective was to determine best practice(s) to reduce horseweed prior to soybean [Glycine max (L.) Merr.]. Treatments included: fall-planted cover crop [CC; cereal rye (Secale cereale L.) or none], fall-applied herbicide (saflufenacil or none), and spring-applied herbicides (dicamba, 2,4-D ester, or none). We hypothesized horseweed densities would be reduced the most where all factors were combined. Saflufenacil suppressed horseweed densities from application through March, when densities increased due to a lack of competition from other winter weeds. Spring herbicides decreased horseweed densities until soybeans reached V1 in 2017, but in 2018 lost efficacy after CC termination. CC alone resulted in the longest horseweed suppression. The combination of spring herbicides and CC usually reduced horseweed densities to near zero between the CC termination and soybean planting. However, some low densities seen soon after soybean planting could be problematic. Further research must be conducted to determine the best integrated horseweed management system until soybean canopy closure.