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Journal articles on the topic 'Seedling tubes'
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1
Sharew, Hailu, and Anne Hairston-Strang. "A Comparison of Seedling Growth and Light Transmission among Tree Shelters." Northern Journal of Applied Forestry 22, no. 2 (2005): 102–10. http://dx.doi.org/10.1093/njaf/22.2.102.
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Abstract Survival, height, and diameter growth of seedlings were evaluated for three years after planting using five types of tree shelters and seven species: green ash (Fraxinus pennylvanica), northern red oak (Quercus rubra L.), pin oak (Q. palustris), American sycamore (Platanus occidentalis), black walnut (Juglans nigra L.), flowering dogwood (Cornus florida), and eastern white pine (Pinus strobus). Differences in shelter environments were measured, including: light transmission measured as percent photosynthetic photon flux, ratio of red:far red (r:f-r) light from the red and far-red wavelengths, and air temperature inside the tubes. The differences seen in seedling survival were not significant (p < 0.05) for the presence or type of tree tube, with an average survival of 96% for all but two species. For most species, seedlings grown in high light-transmitting tubes with proportional r:f-r ratio light showed superior height growth (e.g., Miracle Tube, Tree-Pro, and Protex). Diameter growth generally decreased in shelters. Sycamore showed no significant benefit from the use of tubes. The lowest diameter increments were seen using Tubex brown and Mesh Guard shelters, which had low light transmission with high r:f-r ratio and mechanical damage, respectively. Light transmission in translucent tree tubes was within the ranges found in open canopy forest, but the proportion of growth-promoting far-red wavelength was generally lower. In tubes with higher light transmission, r:f-r ratio is closer to natural ranges for that light level. For tubes with lower light transmissivity, this information suggests that seedling height growth might be improved if red wavelengths were blocked more strongly.North. J. appl. For. North. J. Appl. For. 22(2):102–110.
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Woods, Michaela J., Meredith Cobb, Katie Hickle, and Ryan W. McEwan. "Assessing the Efficacy of Seedling Planting as a Forest Restoration Technique in Temperate Hardwood Forests Impacted by Invasive Species." Forests 10, no. 8 (2019): 699. http://dx.doi.org/10.3390/f10080699.
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The emerald ash borer (Agrilus planipennis Fairmaire; EAB) is an invasive insect that causes mortality of trees in the genus Fraxinus, creating canopy gaps that may facilitate invasion by exotic plants. Planting native tree seedlings under EAB-infested Fraxinus may accelerate succession and preclude invasive plant expansion; however, the effectiveness of this approach has not been experimentally tested. We assessed understory seedling planting of Quercus rubra, Carya laciniosa, and Juglans cinerea in EAB-infested forests, where the invasive shrub Lonicera maackii (Amur honeysuckle) was removed. We tested whether the use of plastic tree shelters (“tree tubes”) or planting season (fall versus spring) contributed to the success of the reforestation plan by measuring growth rates (cm/yr) and survivorship two and seven years after planting. After seven years, seedling survivorship was <25% for all species and planting techniques. Quercus rubra exhibited poor survivorship with one seedling surviving to the conclusion of the experiment. Juglans cinerea and C. laciniosa had higher survivability and growth rates than did Q. rubra after two and seven years. Effects of tree tubes were weak and temporary. After 2 years, Q. rubra seedling survivorship was higher in tree tubes; however, by the end of the experiment 29 of the 30 Q. rubra seedlings in tree tubes had died. Juglans cinerea seedlings grew faster when planted in the fall compared to the spring, but overall survivorship of these seedlings was unaffected by planting season. Neither the use of tree shelters nor the planting season contributed to the growth or survival of C. laciniosa seedlings. In summary, our results indicate that seedling planting of Carya and Juglans may be a useful way to increase biodiversity in regenerating forests; however, the resource-expensive processes of over-wintering seedlings and using tree shelters may not increase the success of reforestation efforts.
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Coelho, Victor Peçanha de Miranda, Kelly Martins Rosa, Paulo Eduardo Branco Paiva, Édimo Fernando Alves Moreira, and Mychelle Carvalho. "Fertigation and growth regulator on coffee seedling production in tubes." Pesquisa Agropecuária Tropical 48, no. 4 (2018): 350–57. http://dx.doi.org/10.1590/1983-40632018v4852148.
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ABSTRACT The use of quality seedlings is important in establishing a productive coffee crop. However, the most widely used method to produce coffee seedlings is time consuming (6-12 months) and lacks new production technologies. This study aimed to assess the use of fertigation and a growth regulator in the production of coffee seedlings, in order to develop a system faster than the conventional method. For that, Topázio coffee cultivar seeds were pre-germinated and planted in tubes filled with substrate (composted pine bark), in a protected nursery. A randomized block design was used, in a 4 x 2 (fertigation levels x the use or not of growth regulator) factorial scheme, with four replications. Daily fertigation positively influenced all the growth variables evaluated. The foliar spraying of the growth regulator had little effect on seedling growth. When compared to the conventional system described in the literature, the coffee seedling production system described here reduced, by around 60 days, the production time and enables a large-scale production.
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Mello, Bruna Finotii Fonseca Reis de, Mateus Vieira Trevisan, and Fábio Steiner. "QUALITY OF CUCUMBER SEEDLINGS GROWN IN DIFFERENT CONTAINERS." JOURNAL OF NEOTROPICAL AGRICULTURE 3, no. 1 (2016): 33–38. http://dx.doi.org/10.32404/rean.v3i1.820.
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The use of high quality seedlings is a key factor for the success of vegetable production, and the container size and design characteristics of the containers are important determinants of seedling quality. A experiment was conducted to investigate the effects of different container types on quality of cucumber seedlings (Cucumis sativus L., cv. Aodai Melhorado). Seedlings were grown in a seedling nursery with shadow protection at 50% in different containers: (i) 128-cell trays; (ii) 64-cell trays; (iii) tubes of 120 cm3; and (iv) plastic cups of 180 cm3. The plant height, diameter, root length, shoot dry matter, root dry matter, sturdiness quotient (SQ), shoot:root dry matter ratio (SRR) and Dickson quality index (DQI) were measured at 21st days after sowing. The production of cucumber seedlings in 64-cell trays, polypropylene tubes of 120 cm3 and plastic cups of 180 cm3 resulted in the highest values for the majority of investigated traits. The tray of 128-cells results in lower quality cucumber seedlings compared to other containers. Tubes with volume of 120 cm3 and plastic cups with volume of 180 cm3 are more appropriate containers for the production of high quality cucumber seedlings. The DQI is a good indicator of the standard of quality of cucumber seedlings.
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Waddington, John, and Marvin C. Snoop. "Using small tubes to measure root elongation of newly germinated alfalfa seedlings in relation to moisture." Canadian Journal of Plant Science 74, no. 2 (1994): 215–19. http://dx.doi.org/10.4141/cjps94-045.
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A method of growing newly germinated seedlings in small tubes was developed to enable the study of early root elongation. Three newly germinated alfalfa (Medicago sativa L.) seeds were placed in tubes of various diameters and volumes filled with sand at several moisture tensions, and the tubes were sealed to prevent moisture loss. For the first 4 d, roots elongated at approximately 8 mm d−1 in polyvinyl chloride plastic tubes holding 60 mL of sand with a moisture tension of 100 kPa or less. After the initial 4 d, root elongation continued at a slower rate, and branch roots developed before termination of the experiments at 12 d after germination. At a moisture tension of 300 kPa, root elongation was markedly less than at 100 kPa, and was zero at moisture tensions of 500 kPa or greater. In round-bottom glass tubes, root elongation rate was significantly slower in a sand volume of 23 mL than in 65 mL, and there was evidence of slower seedling development as the diameter of the tubes was reduced from 20 to 15 mm. Wax plus masking tape or nylon tape were equally effective in sealing the sides of tubes formed from the two halves of a plastic pipe previously cut lengthwise. A plastic cap plus wax was significantly better than plastic film for sealing the bottom ends of plastic tubes. Neither aeration nor replacement of water with a dilute nutrient solution had an effect on root elongation of young seedlings. Key words: Alfalfa, seedling, root elongation, moisture stress, Medicago sativa
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Lopes, Emerson Delano, Cláudio Lúcio Fernandes Amaral, and Adalberto Brito Novaes. "DESEMPENHO NO CAMPO DE MUDAS DE Eucalyptus urophylla, Eucalyptus camaldulensis E Corymbia citriodora PRODUZIDAS EM DIFERENTES RECIPIENTES." FLORESTA 44, no. 4 (2014): 589. http://dx.doi.org/10.5380/rf.v44i4.26480.
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Avaliou-se a produção de mudas de Eucalyptus urophylla, E. camaldulensis e Corymbia citriodora em blocos prensados e em dois modelos de tubetes por meio da avaliação da sobrevivência e do crescimento inicial das mudas. A sobrevivência foi avaliada aos sessenta dias e o crescimento inicial em altura e diâmetro ao nível do solo ao décimo mês pós-plantio. Foi utilizado o delineamento em blocos casualizados com cinco repetições. Mudas de E. urophylla e E. camaldulensis produzidas nos blocos e nos dois modelos de tubetes e mudas de C. citriodora produzidas nos dois modelos de tubetes obtiveram altas taxas de sobrevivência. Já as mudas de C. citriodora produzidas nos blocos apresentaram a menor média de sobrevivência no estudo. As médias de crescimento inicial das mudas de E. urophylla produzidas nos blocos e tubetes de 50 cm3 foram superiores às encontradas para mudas produzidas em tubetes de 35 cm3. Para E. camaldulensis e C. citriodora, as médias de crescimento inicial foram semelhantes nos três recipientes. Recomenda-se a produção de mudas de E. urophylla em tubetes de 50 cm3 ou em blocos prensados. As mudas de E. camaldulensis podem ser produzidas nos três recipientes, e C. citriodora nos tubetes de 50 e 35 cm3.Palavras-chave: Qualidade de mudas; desempenho pós-plantio. AbstractPerformance in the field of Eucalyptus urophylla, Eucalyptus camaldulensis and Corymbia citriodora produced in different containers. We evaluated the production of Eucalyptus urophylla, E. camaldulensis and Corymbia citriodora in pressed blocks and two tubes models by the evaluation of survival and early growth of seedlings. We assessed survival at sixty days and initial growth in height and diameter at ground level to the tenth month after planting. We used a randomized block design with five replications. Seedlings of E. urophylla and E. camaldulensis produced in blocks, and in two tube models, and seedlings of C. citriodora produced in two tube models had high survival rates. On the other hand, seedlings of C. citriodora produced in blocks presented the lowest survival mean. The initial seedling growth mean of E. urophylla produced in blocks and tubes of 50 cm3 were higher than for seedlings grown in tubes of 35 cm3. In relation to E. camaldulensis and C. citriodora the average initial growth were similar in the three containers. Production of seedlings of E. urophylla is recommended in tubes of 50 cm3 or in compressed blocks, E. camaldulensis seedlings can be produced in three containers, and C. citriodora in tubes of 50 and 35 cm3.Keywords: Seedling quality; post-planting performance.
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Runde, Douglas E., Dale L. Nolte, Wendy M. Arjo, and William C. Pitt. "Efficacy of Individual Barriers to Prevent Damage to Douglas-Fir Seedlings by Captive Mountain Beavers." Western Journal of Applied Forestry 23, no. 2 (2008): 99–105. http://dx.doi.org/10.1093/wjaf/23.2.99.
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Abstract We tested the ability of individual tree seedling protectors to deter mountain beavers from damaging Douglas-fir seedlings. Using captive mountain beavers in field pens, we tested 20 products representative of a wide range of barriers suitable for protecting individual tree seedlings from rodent damage. Eleven products protected 95% or more of seedlings from damage. Tree shelters and fabric shelters provided the most protection; 98 and 95% of seedlings were undamaged, respectively. Rigid mesh protector tubes protected 81% of seedlings, and protection netting protected 55% of seedlings. Purchase prices varied widely; protection netting was least expensive, followed by rigid mesh tubes, fabric shelters, and tree shelters. Seedling growth was greatest within fabric shelters and plastic tree shelters. Materials used to construct 15 of the 20 tree protectors were tested using captive mountain beavers in small sheltered pens. Here, samples of barrier materials were used to block access to a favored food. The four materials that excluded all test animals in all trials were from unvented tree shelters with solid seamless walls. Seven materials failed to exclude any animals in the sheltered-pen trials.
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Teixeira, Ednilson Carvalho, Sylvana Naomi Matsumoto, André Felipe Fialho Ribeiro, et al. "Morphophysiology and quality of yellow passion fruit seedlings submitted to inhibition of gibberellin biosynthesis." Acta Scientiarum. Agronomy 43 (July 5, 2021): e51541. http://dx.doi.org/10.4025/actasciagron.v43i1.51541.
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The aim of this study was to verify if a growth reduction of yellow passion fruit seedlings’ growth morphophysiology and quality could be changed by paclobutrazol applied through seedling immersion. The experiment was conducted in a greenhouse, with seedlings grown in polyethylene tubes (290 cm3), with substrate. At 40 days after sowing, the seedlings were immersed in an aqueous solution of paclobutrazol at concentrations of 0, 50, 100, 150, and 200 mg L-1. The experiment was conducted in a randomized block design, with five treatments (paclobutrazol concentrations) and four replicates. At 15 and 30 days after treatment, growth characteristics were evaluated. At the end of the assay, destructive evaluations related to mass determination, total leaf area, and seedling quality index were performed. Paclobutrazol treatment induced restrictions in seedling growth, except for fresh and dry mass of root and total fresh mass. Based on these characteristics, the increase in values induced by paclobutrazol was verified. The seedling quality, defined by the major value of the Dickson quality index and a smaller robustness index, was higher when submitted to paclobutrazol treatment.
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Jellani, G., MJ Atif, H. Ullah, M. Ali, and M. Musa. "Influence of seedling age on cucumber (Cucumis sativus L.) production." SAARC Journal of Agriculture 13, no. 2 (2016): 214–21. http://dx.doi.org/10.3329/sja.v13i2.26581.
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Cucumber crop was evaluated for the influence of seedling age on its production during two consecutive years of 2011 and 2012 on experimental area of National Agricultural Research Center (NARC), Islamabad, Pakistan. Nursery of cucumber was raised in polythene tubes under protected structures (walk-in tunnels). Seedling transplantation of three different ages viz., 30, 45 and 60 days were compared with direct seeding in the open field. Seedling transplantation produced fruits earlier (22 days), increased availability period (41 days) as compared to direct seeded crop. Transplantation of 45 and 60 days old seedlings produced higher fruits yield of cucumber with higher gross return and gross margin. The results revealed that transplantation of 45 to 60 days old seedlings was suitable for achieving fruits earlier and profitable cucumber production technology.SAARC J. Agri., 13(2): 214-221 (2015)
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Jain, Devender K., and R. J. Rennie. "Use of spermosphere model for the screening of wheat cultivars and N2-fixing bacteria for N2 fixation." Canadian Journal of Microbiology 32, no. 4 (1986): 285–88. http://dx.doi.org/10.1139/m86-058.
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The spermosphere model showed very high seedling-to-seedling variation in the ability to induce acetylene-reducing activity in bacteria associated with wheat roots. Several seedlings failed to induce nitrogenase in N2-flxing strains of Bacillus and Azospirillum brasilense. Increasing the concentration of yeast extract or the inoculum density, adding NaOH solution in the side arm of Pankhurst tubes to absorb CO2, and vernalizing the seeds did not increase the percentage of nitrogenase-positive tubes and did not decrease variation in acetylene-reducing activity. Increasing the incubation temperature from 25 to 27 °C induced nitrogenase in Bacillus, but not in Azospirillum strains; at 30 °C nitrogenase was also induced in Azospirillum strains. It appears that the spermosphere model is not a practical technique for screening nitrogenase induction by wheat, unless the use of genetic lines of unimpeachable uniformity can provide control of variability.
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Wallstedt, Anna, Andrew Coughlan, Alison D. Munson, Marie-Charlotte Nilsson, and Hank A. Margolis. "Mechanisms of interaction between Kalmia angustifolia cover and Picea mariana seedlings." Canadian Journal of Forest Research 32, no. 11 (2002): 2022–31. http://dx.doi.org/10.1139/x02-124.
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Sites dominated by Kalmia angustifolia L. are often associated with slow decomposition of organic matter, decreased nitrogen (N) mineralization rates, and low black spruce (Picea mariana (Mill.) BSP) productivity. The objective of this study was to separate the effects of belowground competition by Kalmia from the effects of water-soluble soil phenols on black spruce seedlings growing under different levels of Kalmia cover. A factorial greenhouse bioassay was established in which black spruce seedlings were grown for 6 months in intact blocks of soil with three different levels of Kalmia cover. The soil was treated with charcoal to reduce the amounts of water-soluble phenols, and (or) tubes were inserted to exclude Kalmia roots. At low Kalmia cover, reducing the level of belowground competition increased seedling biomass by 134%. However, reducing belowground competition did not increase seedling biomass at the two higher levels of Kalmia cover. It is possible that seedling biomass remained low because of an increased immobilization of N in the organic layer. Furthermore, the proportion of ectomycorrhiza morphotypes differed among seedlings growing under different levels of Kalmia cover. The effect of water-soluble phenols on seedling growth remains uncertain, since we observed a confounding effect of the charcoal treatment on soil microbial biomass and seedling response.
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Silva, César Antônio da, Durval Dourado Neto, Cícero José da Silva, and Carlos Alessandro de Freitas. "DEVELOPMENT OF HYMENAEA COURBARIL SEEDLINGS IN FUNCTION OF CONTAINERS AND IRRIGATION BLADES." Revista Árvore 40, no. 3 (2016): 487–98. http://dx.doi.org/10.1590/0100-67622016000300012.
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ABSTRACT The objective of this work was to evaluate the effect of container sizes and irrigation levels on "jatoba" (Hymenaea courbaril L.) seedlings development. The experiment was conducted in a greenhouse from September 2010 to March 2011. The design was in randomized blocks, with three replications in split plots, in a 2 x 5 scheme. Two container sizes (rigid pots of 3.1 L and stiff plastic tubes of 4.0 L) were used in the plots, while five drip irrigation levels (20%, 40%, 60% 80% and 100% of potential evapotranspiration - ETp) were used in the subplots. The irrigations were accomplished daily. Each subplot was constituted by eight seedlings. In the period from 80 to 200 days after sowing (DAS), the seedling height (AM), stem diameter (DC), leaves number (NF), leaf area (AF), dry matter mass of roots (MSR) and seedling (MSM) and relation between root dry matter mass and aerial part (MSR/MSPA) were evaluated. The stiff plastic tube provided larger ETp, in comparison with the rigid pot and, consequently, more developed seedlings. Irrigation levels from 90% to 100% of ETp provided more vigorous seedlings. The increase of water deficit reduces all the parameters of jatoba seedlings, except the MSR/MSPA ratio.
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Bal, Amandeep, and Christopher P. Chanway. "Evidence of nitrogen fixation in lodgepole pine inoculated with diazotrophic Paenibacillus polymyxa." Botany 90, no. 9 (2012): 891–96. http://dx.doi.org/10.1139/b2012-044.
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Diazotrophic bacteria previously isolated from internal tissues of naturally regenerating lodgepole pine ( Pinus contorta var. latifolia (Dougl.) Engelm.) seedlings were tested for their ability to colonize and fix nitrogen (N) in pine germinants in two experiments. Surface sterilized pine seed was sown in glass tubes containing an autoclaved sand – montmorillonite clay mixture that contained a N-limited nutrient solution labeled with 15N as 0.35 mmol·L–1 Ca(15NO3)2 (5% 15N label). Pine seed was inoculated with one of three of the following bacterial strains: Paenibacillus polymyxa P2b-2R, P. polymyxa P18b-2R, or Dyadobacter fermentans P19a-2R, and seedlings grew for either 27 or 35 weeks. At the end of each plant growth period, P. polymyxa strain P2b-2R was detected in the pine rhizosphere but not inside plant tissues. Pine foliar N concentrations were not affected by bacterial inoculation but significant foliar 15N dilution was observed in seedlings treated with strain P2b-2R (30% and 66%, P < 0.05, in the first and second experiments, respectively). This strain also reduced seedling biomass in both experiments but effects were significant only in the second experiment (36%, P < 0.05). Notwithstanding the negative effect of bacterial inoculation on seedling growth, pine seedlings inoculated with strain P2b-2R derived 30% and 66%, respectively, of their foliar N from bacterial N fixation in two seedling growth experiments. These results demonstrate the possibility that some endophytic diazotrophs facilitate pine seedling growth in N-poor soils.
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Bonfim, Rosana Sousa, Poliana Moreira Lopes, Samuel Gonçalves de Araújo, Marília das Dores Genovez Furtado, Rafaela Ribeiro de Souza, and Márkilla Zunete Beckman-Cavalcante. "Seed characterization of Allamanda puberula A. DC. and seedling production." Ornamental Horticulture 27, no. 3 (2021): 304–13. http://dx.doi.org/10.1590/2447-536x.v27i3.2329.
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Abstract Allamanda puberula is a native species of the Caatinga biome with ornamental and landscaping potential. However, its potential is little explored due to the lack of information about the biology of its seeds and propagation. In this context, a study was carried out in order to characterize the seeds and their potential to produce seedlings in different containers. The experiments were divided into two phases. The first consisted in the characterization of fruits and seeds by evaluating the number of seeds per fruit, their dimensions (length and width), the weight of a thousand seeds, the number of seeds kg-¹, the degree of moisture, germination and emergence. The second phase consisted in the production of seedlings in a nursery, evaluating the growth over the days after sowing (DAS) (15, 30, 45 and 60 DAS) and the effect of the type of container (trays and tubes) for the formation of the seedlings. The species A. puberula has small seeds and a significant number of seeds per fruit. Apparently, there is no physical impediment or type of dormancy that impairs the germination process of the seeds. Seedlings grown in tubes were better in terms of growth and allocation of biomass. However, the indication of the best cultivation container for A. puberula propagated via seeds will depend on the implantation project and the specific characteristics of the field. The characterization of A. puberula seeds showed satisfactory physiological potential for germination and complete seedling formation in the nursery, enabling success in obtaining seedlings through seminiferous propagation.
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Furness, Nancy H., Mahesh K. Upadhyaya, and Douglas P. Ormrod. "Sensitivity of Selected Vegetable and Weed Seedlings to Ultraviolet-B Radiation." HortScience 33, no. 3 (1998): 480e—480. http://dx.doi.org/10.21273/hortsci.33.3.480e.
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Relative sensitivity of selected vegetable and weed seedlings to ultraviolet-B (UV-B) radiation (280–320 nm) was investigated. Seedlings were grown for 4 weeks in a greenhouse, in chambers equipped with UV-B-emitting fluorescent tubes and Mylar (control) and cellulose acetate (UV-B) filters. UV-B radiation reduced seedling height, leaf area, and leaf fresh weight in tomato (Lycopersicon esculentum `Cour Di Bue'), broccoli (Brassica oleracea var. Italica `Purple Sprouting'), cabbage (Brassica oleracea var. Capitata `Red Drumhead'), and cucumber (Cucumis sativus `Straight Eight'), leaf area and leaf fresh weight in beet (Beta vulgaris `Cylindra' and `Early Wonder'), seedling height and leaf area in spinach (Spinacia oleracea `Long Standing Bloomsdale'), lettuce (Lactuca sativa ``Red Salad Bowl Everest') and `Savoy' cabbage, and seedling height in `Chinese Tip Top' cabbage and lettuce (`Saladin'). `Winterton' cabbage was not affected. UV-B radiation decreased leaf area and leaf fresh weight in common chickweed (Stellaria media) and corn spurry (Spergula arvensis) and seedling height in green foxtail (Setaria viridis) and redroot pigweed (Amaranthus retroflexus). Tillering was stimulated in response to UV-B in green foxtail. There was no effect of UV-B on lady's-thumb (Polygonum persicaria) growth. Leaf number was not affected by exposure to UV-B in any species. The differential morphological sensitivity of vegetable and weed seedlings may result in altered competitive relationships under enhanced UV-B levels expected with the depletion of the earth's ozone layer.
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Thomson, J., U. Matthes-Sears, and R. L. Peterson. "Effects of seed provenance and mycorrhizal fungi on early seedling growth in Piceamariana." Canadian Journal of Forest Research 20, no. 11 (1990): 1739–45. http://dx.doi.org/10.1139/x90-231.
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The importance of provenance and fungal species effects on mycorrhiza formation in Piceamariana was determined. Seed was collected from two sites near Chapleau, Ontario. One provenance was collected from an upland site with sandy soil, the second from a lowland site with peaty soil. Seedlings were grown under aseptic conditions in test tubes. Two experiments were performed: in the first, seedlings were inoculated with Hebelomacylindrosporum, Laccarialaccata, or Paxillusinvolutus, whereas in the second, seedlings were inoculated with Laccariabicolor, Laccarialaccata, Laccariaproximo or noninoculated agar plugs. Counts of ectomycorrhiza and lateral root formation were analyzed for significance with two-way factorial ANOVAS. When inoculated with L. laccata, seedlings from the lowland seed source had significantly more mycorrhizal second order lateral roots than seedlings from the upland seed source. Lowland seedlings also had greater shoot dry weight and foliage length values. However, overall differences between provenances were small. In contrast, differences between fungal treatments were pronounced. Both L. laccata and L. bicolor initiated good ectomycorrhiza formation and increased seedling growth.
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Pipas, Michael J., and Gary W. Witmer. "Evaluation of Physical Barriers to Protect Ponderosa Pine Seedlings from Pocket Gophers." Western Journal of Applied Forestry 14, no. 3 (1999): 164–68. http://dx.doi.org/10.1093/wjaf/14.3.164.
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Abstract A 2 yr study on the Rogue River and Mt. Hood National Forests in Oregon evaluated physical barriers for protection of Pinus ponderosa seedlings against damage by Thomomys talpoides. Seedlings protected with one of three weights of: (1) plastic mesh tubing (Vexar®) or (2) sandpapertubing (Durite®) were evaluated against control seedlings. On the Rogue River sites, Vexar® seedlings had the highest survival (62.6%), followed by the controls (59.1%), then Durite® seedlings (17.9%). Gophers were the primary cause of death for the Vexar® seedlings, versus desiccation for the Durite® seedlings. On the Mt. Hood sites, heavyweight Vexar® seedlings had the highest survival (35.4%), medium-weight Durite® seedlings the lowest (2.7%). Seedling mortality caused by gophers was highest for controls (70.2%), followed by light-weight (62.2%) and heavy-weight (53.9%) Vexar® treatments. Overall survival was low (Rogue River = 42%, Mt. Hood = 19.8%). Growth was greatest for the control seedlings but only significantly greater than growth of Durite® seedlings on the Rogue River sites. Growth of seedlings was not compromised by the Vexar® tubing. Although neither type of tubing was highly protective, Vexar® tubes performed better than Durite® tubes. West. J. Appl. For. 14(3):164-168.
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Enns, Linda C., Margaret E. McCully, and Martin J. Canny. "Branch roots of young maize seedlings, their production, growth, and phloem supply from the primary root." Functional Plant Biology 33, no. 4 (2006): 391. http://dx.doi.org/10.1071/fp06029.
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Branch root development on the primary root of maize (Zea mays L.) seedlings was followed for 9 d after planting. This period includes the shift from seedling heterotrophy to autotrophy. Linear density of branches in the basal region ranged from ~38 cm–1 at the base to ~10 cm–1 beyond 10 cm. Branch roots in the first ~8 cm were produced before assimilate was available. Branch length decreased from ~26 mm at 1 cm along the primary root to ~8 mm at 10 cm from the base. Without the cotyledon, branch root density in the basal region was ~10 cm–1 and roots were short (~5 mm). Beyond 8–10 cm both measurements matched those of intact seedlings. Dark-grown seedlings had basal branch root densities higher than those without cotyledons but none beyond 10 cm. There were more and smaller diameter sieve tubes in the basal region of the primary root. These decreased distally in number but had larger diameters where branches formed after assimilate was available. Proliferation of basal branch roots in very young seedlings can have major advantages for successful seedling establishment in the field and could be screened for without difficulty.
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MENDONÇA, ANDREA VITA REIS, JIOVANA PEREIRA AMORIM SANTOS, DENISE DOS SANTOS VILA VERDE, MANUELA OLIVEIRA DE SOUZA, and JOSIVAL SANTOS SOUZA. "PRODUCTION OF SEEDLINGS OF Psidium cauliflorum Landrum & Sobral." Revista Caatinga 33, no. 2 (2020): 433–45. http://dx.doi.org/10.1590/1983-21252020v33n216rc.
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ABSTRACT In the absence of knowledge about the procedures for production of seedlings of particular tree species, determining the nursery production period and quality standards are normally priority aspects for studies. As there is no information on the propagation of P. cauliflorum in the literature, the objective of this study was to determine the length of stay in the nursery, the size of the container and the quality standards for the production of seedlings of this species, based on the performance in the nursery and in the field. The work was carried out in two stages. In the first, seedling growth was analyzed in the nursery and in the second stage their performance was analyzed in the field. We tested three container sizes: 55 cm3 (12.5 cm-length x 2.9 cm-internal diameter), 180 cm3 (13.5 cm x 5.2 cm) and 280 cm3 (19.0 cm x 5.2 cm) and different periods of seedling production in tubes (15, 30, 45, 60, 75, 90, 105 and 120 days). It is recommended that P. cauliflorum seedlings be grown in containers of 180 cm3 (13.5 cm x 5.2 cm) and remain in these containers for at least 120 days. The experiment to assess post-planting performance was crucial to obtain conclusive results for the production of P. cauliflorum seedlings.
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Camara, Rodrigo, Cristiane Figueira da Silva, Marcos Gervasio Pereira, Gabriela Cavalcanti Alves, Dereck Halley Anthony Alves Ferreira, and Lucas Amaral de Melo. "PRODUCTION OF Eucalyptus urophylla x Eucalyptus grandis SEEDLINGS WITH DIFFERENT FERTILIZERS." FLORESTA 50, no. 2 (2020): 1231. http://dx.doi.org/10.5380/rf.v50i2.62303.
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Mineral fertilization is an important practice that contributes to the production of seedlings with satisfactory quality. This study aimed to evaluate the effect of the application of potassium chloride (KCl) and monoammonium phosphate (MAP) on growth and nutrition of Eucalyptus urophylla x Eucalyptus grandis seedlings. The experiment was conducted in full sun, with direct sowing in tubes containing composite substrate (Pinus bark, coconut fiber, bovine manure and vermiculite). The experimental design was a randomized block design in a 5 x 2 factorial scheme, with five doses of KCl (0.0, 0.025, 0.050, 0.100, and 0.200 g seedling-1) and two doses of MAP (0 and 0.10g seedling-1), with four replicates. At 120 days, the effect of the interaction between the KCl and MAP doses was verified for the variables: diameter at root collar, dry mass of the aerial part (DMAP) and total (TDM), Dickson Quality Index, N content, P K in the aerial part, K content in the roots, absorption efficiency (AE) of N and P. For the variables: height (H); leaf area; root dry mass (RDM); H/DRC and DMPA/RDM ratios; and N and P content in the roots, only effect of the application of MAP is observed, whereas for AE_K the effect was only of KCl. Thus, there is variation in the effect of KCl doses as a function of morphological and nutritional variables evaluated. In general, the best seedling growth and nutrition occurs with the applied dose of 0.100 g KCl + 0.10 g MAP seedling -1.
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Cook, SJ, and D. Ratcliff. "Effect of fertilizer, root and shoot competition on the growth of Siratro (Macroptilium atropurpureum) and green panic (Panicum maximum var. trichoglume) seedlings in a native speargrass (Heteropogon contortus) sward." Australian Journal of Agricultural Research 36, no. 2 (1985): 233. http://dx.doi.org/10.1071/ar9850233.
Full textAbstract:
The effect of root and shoot competition and the application of fertilizer on the growth of Siratro (Macroptilium atropurpureum) and green panic (Panicum maxinzum var. trichoglume) seedlings under supplementary irrigation in an existing native grassland dominated by Heteropogon contortus was studied. The seedlings were grown in both the presence and absence of root competition and varying levels of shoot competition. Root competition was prevented by the use of steel tubes while shoot competition was varied by: clipping the native pasture to a height of either 3-5 cm or 10-15 cm every 7-10 days, leaving the native sward unclipped, and unclipped sward with wire-netting guards fitted around each seedling to prevent overtopping and facilitate light penetration. Seedling growth was assessed by determining dry weights after 29 days and also by measuring plant heights, leaf and tiller numbers and the leaf widths at 7-day intervals during this period. Application of superphosphate and nitrogen fertilizer increased the growth of both species, the initial effects being evident within 1-2 days of seedling emergence. However, at both fertilizer levels the growth of both species was primarily affected by root competition for nutrients. Where fertilizer was applied and no root competition was present heavy shading in the lower 5-10 cm of the sward canopy restricted seedling growth by reducing tiller and leaf production. The removal of shoot competition increased seedling yields fivefold whereas the removal of root competition and the removal of both root and shoot competition increased yields by 25- and 45-fold, respectively. Siratro and green panic yields were the same in the absence of root competition but Siratro yields were 11 times those of green panic where root competition was present.
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Browning, Mark H. R., and Roy D. Whitney. "Responses of jack pine and black spruce seedlings to inoculation with selected species of ectomycorrhizal fungi." Canadian Journal of Forest Research 21, no. 5 (1991): 701–6. http://dx.doi.org/10.1139/x91-096.
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Seedlings of jack pine (Pinusbanksiana Lamb.) and black spruce (Piceamariana (Mill.) B.S.P.) were inoculated with liquid cultures of fragmented hyphae of 10 species of ectomycorrhizal fungi and grown in either aseptic culture tubes for 20 weeks or nonaseptic pots for 16 weeks. Seedlings in pots received more total nutrients and produced larger root systems than those in tubes. Four of the fungi produced higher levels of colonization associated with these larger root systems. Short-root density of black spruce was increased compared with that of uninoculated seedlings by inoculation with Laccariabicolor (Maire) Orton, Hebelomacylindrosporum Romagnési, or Thelephoraterrestris Ehrh. ex Fr. Colonization of jack pine by Rhizopogonrubescens (Tul.) Tulasne, L. bicolor, H. cylindrosporum, or Pisolithustinctorius (Pers.) Coker & Couch resulted in greater short-root densities than in uninoculated controls. Inoculation of potted black spruce with Laccariaproxima Boudier resulted in larger shoot weights and those inoculated with H. cylindrosporum had smaller root weights than did uninoculated seedlings. Both fungi resulted in increased shoot/root dry-weight ratios in black spruce. In contrast with black spruce, seedling weights were not affected by inoculation of jack pine with the same fungal species. However, inoculation of jack pine with R. rubescens resulted in a significantly higher shoot/root dry-weight ratio.
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Villa, Fabíola, Daniel Fernandes da Silva, Thiago Augusto Peron, and Éder Junior Mezzalira. "Initial development of Physalis seedlings in substrates and containers." Comunicata Scientiae 9, no. 1 (2018): 50–57. http://dx.doi.org/10.14295/cs.v9i1.1313.
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The objective of this study was to evaluate the growth of Physalis peruviana and Physalis pubescens in containers and substrates, as well as the growth of transplanted P. pubescens seedlings into different containers and substrates. It was used for transplanting experiment (E1) plastic bags, disposable plastic glasses and plastic tubes containing four substrates: oxisol; commercial substrate; commercial substrate + fine washed sand; and commercial substrate + oxisol + fine washed sand. For the experiment of containers x substrates (E2) it was used polystyrene and polypropylene trays, both with 200 cells containing two substrates: vermiculite + commercial substrate and vermiculite + oxisol. For the experiment of containers x substrates (E3), it was used polystyrene trays with 128 and 200 cells and plastic tubes containing four substrates: commercial substrate, oxisol, fine washed sand, oxisol + fine washed sand and oxisol + fine washed sand + commercial substrate. The experimental design used in E1, E2 and E3 was randomized blocks in factorial 3x4, 2x2, and 3x5, respectively, containing 4 replicates and 10 plants per plot. The use of commercial substrate Húmus Fértil® for P. pubescens seedlings transplanted from seedbed to containers such as plastic glasses or plastic bags provides better seedling growth. For Physalis peruviana, better results are verified in the use of polypropylene tubes containing washed fine sand + commercial substrate Húmus Fértil® + oxisol or washed fine sand + oxisol. Better results for formation of P. pubescens seedlings were verified by using expanded polystyrene trays containing oxisol + vermiculite mixture.
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Robison, Mary M., Matthew P. L. Smid, and David J. Wolyn. "High-quality and homogeneous Arabidopsis thaliana plants from a simple and inexpensive method of hydroponic cultivation." Canadian Journal of Botany 84, no. 6 (2006): 1009–12. http://dx.doi.org/10.1139/b06-054.
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A methodology is presented for the hydroponic cultivation of Arabidopsis thaliana (L.) Heynh. that is simple and inexpensive to construct from easily obtainable and reusable materials. High-quality and uniform plant material, free of algae and disease, are consistently produced through all life-stages. Minor modifications to previous protocols that reduce cost and labour include the use of small food-storage containers with snap-on lids, aluminum foil wrap to cover the containers to occlude light, commercial hydroponic fertilizer as nutrient solution, and clipped 1.5 mL microfuge tubes as plug holders. Seed is germinated on nutrient agar plates, instead of directly on rockwool plugs; after the seedlings have grown to the six-leaf stage, they are removed from the plates and the roots are enclosed within rockwool plugs that have been cut longitudinally. Subsequent seedling growth is very uniform and the elimination of oversowing and subsequent thinning results in a dramatic reduction in seed and seedling wastage.
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Yadav, Subedar. "Fungal strains for mycological production of citric acid." International Journal of Pharmaceutical Chemistry and Analysis 8, no. 2 (2021): 59–61. http://dx.doi.org/10.18231/j.ijpca.2021.012.
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Citric acid has become an important raw material for general industrial use with many varied and expanding applications such as iron, steel, treatment and conditioning of industrial water supplies, preparation of alkyl resins, paints and in the printing of calico and textile industries. Mycological Production of citric acid includes preparation and sterilization of different media, culture medium, and seedling of culture tube, incubation of culture tubes, determination of citric acid formed and molasses left unfermented during the course of present investigation. The Present work deals mainly selection of potent strains of fungus.
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Marler, Thomas E. "Substrate pH and Papaya Seedling Growth." HortScience 33, no. 3 (1998): 499b—499. http://dx.doi.org/10.21273/hortsci.33.3.499b.
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Two studies were conducted to determine the influence of pH on `Waimanalo' papaya seedling growth and morphology. The seedlings were grown in clear, plastic tubes with diameter of 7 cm and length of 21 cm, and substrate was silica sand. The substrate was drenched daily with complete nutrient solution. The solution was adjusted to pH of 3, 4, 5, 6, 7, 8, or 9. We used direct-seeded plants in the first study, and plants were harvested following 9.5 weeks of growth. We used transplants in the second study, and plants were harvested following 4 weeks of growth. Dry mass of plants was relatively unaffected by substrate pH within the range of 4 to 9. In both studies; however, dry mass of plants receiving solution with a pH of 3 was reduced. The response pattern was similar for canopy:root ratio, total root length, root growth rate, lateral root thickness, and root tip density. Unit leaf area per unit root length was greatly increased for plants receiving pH of 3, indicating increased susceptibility to drought conditions.
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Peachey, R. Edward, and Carol Mallory-Smith. "Influence of Winter Seed Position and Recovery Date on Hairy Nightshade (Solanum sarrachoides) Recruitment and Seed Germination, Dormancy, and Mortality." Weed Science 55, no. 1 (2007): 49–59. http://dx.doi.org/10.1614/ws-06-051.1.
Full textAbstract:
Understanding the factors regulating recruitment in diverse tillage systems will improve the efficacy of weed-management strategies. Experiments measured the effect of hairy nightshade winter seed position (burial depth) on seedling recruitment and seed germination, dormancy, and mortality. Hairy nightshade seeds were placed in soil tubes at 1 cm below the soil line and buried in the fall so that seeds were positioned in the soil at 1, 6, 13, and 25 cm below the soil surface. Tubes with undisturbed soil and seeds were removed from the field in March, April, and May of 2004 and 2005 and placed in wells in a heated, aluminum block with a linear temperature gradient from 22.7 to 36.0 C at 2.7 C intervals, and recruitment was measured. Seeds were also recovered from the soil tubes to determine effects of seed position on germination rate, mortality, and seed dormancy. Hairy nightshade seedling recruitment was greater for seeds positioned at 6, 13, and 25 cm during the winter than at 1 cm. Seed dormancy and mortality were greatest for seeds positioned at 1 cm, but that did not adequately account for the significant decrease in recruitment at 1 cm compared to seeds buried at 6, 13, or 25 cm. Protecting the seeds buried at 1 cm from rainfall during the winter increased seedling recruitment from 0 to 20% of buried seeds but had a negligible effect on seed mortality and dormancy. Soil density was negatively correlated with recruitment.
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Silva, Oclizio Medeiros das Chagas, Marileydy Martínez Hernández, Rodolfo Soares de Almeida, Ramon Pittizer Moreira, Paulo Sérgio dos Santos Leles, and Lucas Amaral de Melo. "SEEDLINGS OF TREE SPECIES PRODUCED IN SUBSTRATES BASED ON ORGANIC COMPOSTS." FLORESTA 51, no. 2 (2021): 371. http://dx.doi.org/10.5380/rf.v51i2.69047.
Full textAbstract:
The quality of the seedling produced is directly related to substrate composition, so it is essential to select constituents with adequate characteristics. The objective of this study was to evaluate Eucalyptus urophylla, Peltophorum dubium and Eremanthus erythropappus seedlings and to relate the physical and chemical characteristics of the formulated substrates to their quality. For each species, an experiment was carried out in a completely randomized design (CRD), consisting of five treatments, five replicates, and plots composed of 20 seedlings. In order to evaluate the quality of the seedlings, the biometric variables were measured and, as a qualitative analysis, the ease to remove the seedlings from the tubes (ERT) and root aggregation to the substrate (AGGR) were evaluated. Seedlings produced in the substrates formulated with alternative constituents showed higher values when compared to seedlings produced with commercial substrate, for most of the analyzed variables. Coffee husk can be applied in the production of seedlings of P. dubium and E. urophylla. For the formation of E. erythropappus seedlings, none of the formulations tested are recommended.
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Singh, N., T. Phukan, P. L. Sharma, et al. "An Innovative Root Inoculation Method to StudyRalstonia solanacearumPathogenicity in Tomato Seedlings." Phytopathology® 108, no. 4 (2018): 436–42. http://dx.doi.org/10.1094/phyto-08-17-0291-r.
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In this study, we report Ralstonia solanacearum pathogenicity in the early stages of tomato seedlings by an innovative root inoculation method. Pathogenicity assays were performed under gnotobiotic conditions in microfuge tubes by employing only 6- to 7-day-old tomato seedlings for root inoculation. Tomato seedlings inoculated by this method exhibited the wilted symptom within 48 h and the virulence assay can be completed in 2 weeks. Colonization of the wilted seedlings by R. solanacearum was confirmed by using gus staining as well as fluorescence microscopy. Using this method, mutants in different virulence genes such as hrpB, phcA, and pilT could be clearly distinguished from wild-type R. solanacearum. The method described here is economic in terms of space, labor, and cost as well as the required quantity of bacterial inoculum. Thus, the newly developed assay is an easy and useful approach for investigating virulence functions of the pathogen at the seedling stage of hosts, and infection under these conditions appears to require pathogenicity mechanisms used by the pathogen for infection of adult plants.
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Cruz, Gustavo Henrique Miguel da, Fernando França da Cunha, Epitácio José de Souza, Andrisley Joaquim da Silva, and Roberto Filgueiras. "IRRIGATION FREQUENCIES FOR Eucalyptus grandis SEEDLINGS." REVISTA ENGENHARIA NA AGRICULTURA - REVENG 28 (November 26, 2020): 364–74. http://dx.doi.org/10.13083/reveng.v29i1.9669.
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One of the bottlenecks in relation to the production of forest seedlings is irrigation, especially in less-tech nurseries. The small volumes of substrate, where the seedlings develop, lead to low water storage. This fact can lead to water deficit and significant losses in the production of seedlings, generating even mortality. The objective of this study was to determine the best irrigation frequencies for Eucalyptus grandis seedling production in less-tech nurseries. The experiment was conducted between 2013/08/04 and 2013/23/07 (106 days) and conducted in Chapadão do Sul county, Brazil. The experiment was set up in a randomized complete block design, with five replications. Four irrigation frequencies were tested: IF1 (one daily irrigation - 11:00 a.m.), IF2 (two daily irrigations - 11:00 a.m. and 7:00 p.m.), IF3 (three daily irrigations - 07:00 a.m., 11:00 a.m. and 7:00 p.m.) and IF4 (four daily irrigations - 07:00 a.m., 11:00 a.m., 3:00 p.m. and 7:00 p.m.). The sample units were composed of eight seedlings in 50 cm3 conical tubes filled with soil and vermiculite in a volume ratio of 1:1. The irrigation depth was estimated by reference evapotranspiration (Penman-Monteith) multiplied by a crop coefficient equal to two. Plant height, number of definitive leaves, shoot dry mass (root and total), seed quality index, survival and efficiency of water use by eucalyptus seedlings were evaluated. The average daily irrigation depth in the experimental period was 5.2 mm. Based on the results, it is recommended for eucalyptus seedling producers, in less-tech nursery, irrigation management twice per days. (11:00 a.m. and 7:00 p.m.).
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Marques, Léo O. D., Paulo Mello-Farias, Roberto P. de Oliveira, Maximiliano Dini, Walter S. Soares Filho, and Marcelo B. Malgarim. "Emergence Percentage and Speed of Rootstocks for Citriculture in South of Brazil." Journal of Agricultural Science 11, no. 5 (2019): 49. http://dx.doi.org/10.5539/jas.v11n5p49.
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The fact that Brazilian citriculture has focused on few rootstocks poses several phytosanitary risks to the culture and has made genetic improvement programs develop hybrid genotypes to be used as novel alternatives. This study aimed at evaluating the behavior of 42 different rootstocks regarding their emergence percentage and speed in weather conditions experienced in the extreme south of Brazil. Seeds of hybrids developed by the Citrus Genetic Improvement Program (PMG Citros) at the Embrapa Mandioca e Fruticultura (PMG Citros) and cultivars from other citrus growing regions were sown in conical tubes filled with commercial substrate in May 2017. A thoroughly randomized design with 4 replicates, each composed of 45 sampling units, was employed. Emergence percentage and emergence speed of every genotype were evaluated and the ones with the highest emergence percentage of seedlings and the ones with the most precocious emergence were identified. All genotypes completed seedling emergence 98 days after sowing. Seeds of Trifoliata, TSKC &times; CTSW-041 and TSKC &times; CTSW-025 had the highest values of seedling emergence whereas the highest emergence speed indexes were exhibited by genotypes Trifoliata and lemon tree &lsquo;Cravo&rsquo;.
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Bantis, Filippos, and Kalliopi Radoglou. "Testing the potential of LEDs to enhance growth and quality characteristics of Salvia fruticosa." Horticultural Science 46, No. 2 (2019): 98–106. http://dx.doi.org/10.17221/206/2017-hortsci.
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The effect of light-emitting diodes (LED) with broad radiation spectra on developmental, physiological, and phytochemical characteristics of Greek sage (Salvia fruticosa L.) seedlings was assessed. Fluorescent (FL – control) tubes and four LED lights [AP67 (moderate blue, red and far-red), L20AP67 (moderate blue, red and far-red, high green), AP673L (moderate blue, high red) and NS1 (high blue and green, low red, high red : far-red, 1% ultraviolet)] were used in a growth chamber. Seedlings grown under FL, L20AP67 and AP673L exhibited the best morphological and developmental characteristics. FL led to inferior root biomass formation compared to all LEDs. AP67 promoted greater root-to-shoot dry weight ratio and dry-to-fresh overground and root weight ratios, but induced the least morphological and developmental characteristics. NS1 performed well regarding the root biomass production. Total phenolic content and the root growth capacity were not significantly affected. The present study demonstrates that L20AP67 and AP673L LEDs performed equally to FL light regarding the developmental characteristics. AP67 and NS1 may have the potential to be used for compact seedling production.
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Fisher, James T., Gregory A. Fancher, and Earl F. Aldon. "Factors affecting establishment of one-seed juniper (Juniperusmonosperma) on surface-mined lands in New Mexico." Canadian Journal of Forest Research 20, no. 7 (1990): 880–86. http://dx.doi.org/10.1139/x90-118.
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Containerized one-seed juniper (Juniperusmonosperma (Engelm.) Sarg.) were planted on two northern New Mexico mine spoils to evaluate effects of establishment methods and postplanting site conditions on seedling survival and growth. Establishment factors included planting date, mulch, fertilizer regimes, and seedling protection. Wood chip mulch and animal protection provided by rigid plastic mesh tubes or plastic netting improved juniper survival, growth, or both, depending on the study. The forms and rates of fertilizers tested provided no benefits and sometimes decreased survival. Juniper fertilization at planting stimulated the growth of reseeded grass and resulted in greater competition. Perennial weeds that invaded a mechanically cleared planting site also reduced juniper growth and survival. Results point to the need to consider the adverse effects associated with fertilization, time of planting, and order of grass and juniper revegetation.
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Mohamed, Mohamed F., Paul E. Read, and Dermot P. Coyne. "Dark Preconditioning, CPPU, and Thidiazuron Promote Shoot Organogenesis on Seedling Node Explants of Common and Faba Beans." Journal of the American Society for Horticultural Science 117, no. 4 (1992): 668–72. http://dx.doi.org/10.21273/jashs.117.4.668.
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Dry seeds from two lines of common bean (Phaseolus vulgaris L.) and one cultivar of faba bean (Vicia faba L.) were germinated on Murashige and Skoog (MS) medium containing B vitamins, 30 g sucrose/liter, and either 2.5, 5.0, or 7.5 μm benzyladenine (BA). Axenic seed cultures were grown at 22 to 24C in darkness and under continuous light from cool-white fluorescent tubes (40 μmol·m-2·s-1). Explant tissues were prepared from cotyledonary nodes (CN) and primary nodes (PN) of 14-day-old seedlings. Explants were cultured on corresponding seedling growth medium and maintained under continuous cool-white light (40 μmol·m-2·s-1). The percentages of CN and PN (in one line of common bean) explants that regenerated shoots and the number of shoots per explant (in all germplasm) were highest when nodal tissues were prepared from seedlings germinated in darkness. These responses were optimal on medium containing 5 μm BA during seedling growth and subsequent culture of explants. The number of shoots per explant was two to five times higher on explants cultured on medium with 0.25 to 1.0 μm forchlorfenuron (CPPU) or thidiazuron (TDZ) than on medium with 5 μm BA. Higher (2.5 and 5 μm) CPPU and TDZ concentrations inhibited shoot elongation and stimulated callus production. Histological analyses indicated that adventitious meristems formed 6 to 8 days after explant culture. Progenies from regenerated plants appeared similar to plants raised from the original seed stocks. Chemical names used: N- (phenylmethyl) -1 H- purin-6-amine (benzyladenine, BA); N- (2-chloro-4-pyridyl)-N'- phenylurea (forchlorfenuron, CPPU); N- phenyl -N' -1,2,3-thiadiazol-5-ylurea (thidiazuron, TDZ).
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Stoffella, Peter J., Michele Lipucci Di Paola, Alberto Pardossi, and Franco Tognoni. "Seedling Root Morphology and Shoot Growth after Seed Priming or Pregermination of Bell Pepper." HortScience 27, no. 3 (1992): 214–15. http://dx.doi.org/10.21273/hortsci.27.3.214.
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Primed, pregerminated, or nontreated seeds of bell pepper (Capsicum annum L.) `Early California Wonder' were grown in controlled conditions for 14 days in glass tubes containing a gel medium. The number of basal roots (one per plant), lateral roots (one per plant), and taproot length (64 mm) did not differ between seed treatments 14 days after seeding. Roots of seedlings from nontreated seeds weighed more than seedlings from primed seeds, and the seedlings had smaller shoot: root ratios than those from pregerminated or primed seeds. Seedlings from pregerminated seeds had heavier and taller shoots than seedlings from nontreated or primed seeds. Taproot length from 1 to 6 days after radicle protrusion increased linearly for all seed treatments. Seedlings from pregerminated seeds initially had longer taproots but had slower linear taproot growth up to 6 days after seeding than seedlings from nontreated or primed seeds.
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Carr, Eric A., and Eric B. Nelson. "Disease-Suppressive Vermicompost Induces a Shift in Germination Mode of Pythium aphanidermatum Zoosporangia." Plant Disease 98, no. 3 (2014): 361–67. http://dx.doi.org/10.1094/pdis-05-13-0466-re.
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Compost amendments to soils can minimize losses from soilborne plant pathogens, yet the mechanisms by which this occurs have not been well elucidated. In the present study, developmental responses of Pythium aphanidermatum zoosporangia to vermicomposts were observed to better understand how suppression of Pythium seedling disease is expressed. Mature zoosporangia were exposed to vermicompost extracts (VCEs) and monitored using time-lapse photomicroscopy. Sterile and nonsterile VCEs inhibited indirect germination and viable zoospore production whereas zoosporangia germinated directly in VCE to produce germ tubes. Additional treatments were tested to determine factors that promote direct over indirect germination. The pH (5 to 9 at 0.001 M) and ionic strength (0.1 to 0.0001 at pH 6) of potassium phosphate buffer did not alter zoosporogenesis compared with sterile water. Decreasing osmotic potentials in glucose and sucrose from –248 to –2,712 kPa or in polyethylene glycol 8000 from –0.335 to –105 kPa led to a decrease in indirect germination with a corresponding increase in direct germination. Significant levels of seed infection were observed within 1 h of exposure to zoospores (produced in sterile water) or to germ tubes (produced in sucrose solution). Our data demonstrate that VCEs suppress zoosporogenesis and stimulate direct germination; however, this did not result in the suppression of germ tube growth and seed infection.
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Chen, Mei-Hsing, and Eric B. Nelson. "Microbial-Induced Carbon Competition in the Spermosphere Leads to Pathogen and Disease Suppression in a Municipal Biosolids Compost." Phytopathology® 102, no. 6 (2012): 588–96. http://dx.doi.org/10.1094/phyto-08-11-0241.
Full textAbstract:
The aim of this study was to understand whether competition for fatty acids in plant seed exudates by compost-derived seed-colonizing microbial communities could explain the suppression of plant infections initiated by sporangia of Pythium ultimum. The germination behavior of P. ultimum sporangia in response to cucumber seeds was measured to determine the impact of seed-colonizing microbes on pathogen suppression. Seed-colonizing microbial communities from municipal biosolids compost utilized cucumber seed exudates and linoleic acid in vitro, reducing the respective stimulatory activity of these elicitors to P. ultimum sporangial germination. However, when sporangia were observed directly in the spermosphere of seeds sown in the compost medium, levels of germination and sporangial emptying did not differ from the responses in sand. The percentage of aborted germ tubes was greater after incubating sporangia in compost medium for 12-h than the level of germ tube abortion when sporangia were incubated in sand. Abortion did not occur if previously germinated sporangia were supplemented with cucumber seed exudate. Furthermore, removal of cucumber seed exudate after various stages of germ tube emergence resulted in an increase in aborted germ tubes over time. Adding increasing levels of glucose directly to the compost medium alleviated germ tube abortion in the spermosphere and also eliminated disease suppression. These data fail to support a role for linoleic acid competition in Pythium seedling disease suppression but provide evidence for general carbon competition mediated by seed-colonizing microbial communities as a mechanism for the suppression of Pythium seed infections in municipal biosolids compost.
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Dias, Gustavo Cardoso de Oliveira, Leonardo Oliveira Medici, Marco Antonio da Silva Vasconcellos, Daniel Fonseca de Carvalho, and Carlos Pimentel. "Papaya seedlings growth using a low-cost, automatic watering controller." Revista Brasileira de Fruticultura 35, no. 2 (2013): 527–35. http://dx.doi.org/10.1590/s0100-29452013000200023.
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The study assessed growth and physiological parameters of 'Sunrise Golden' and 'Tainung 01' papaya seedlings grown in 280mL plastic tubes and watered using a low-cost automatic irrigation system adjusted to operate at substrate water tension for starting irrigation (STI) of 3.0, 6.0 or 9.0 kPa. The water depths applied by the dripping system and drainage were monitored during germination and seedling growth. Germination, emergence velocity index (EVI), leaf area, plant height, shoot and root dry weight, stomatal conductance, relative water content (RWC) and relative chlorophyll content (RCC) were evaluated. Soil nutrient levels were determined by electrical conductivity (EC). Water use efficiency (WUE) corresponded to the ratio of plant dry mass to depth of water applied. STI settings did not affect papaya germination or EVI. System configuration to 3.0 and 6.0 kPa STI exhibited the highest drainage and lowest EC and RCC, indicating soil nutrient loss and plant nutrient deficiency. Drainage was greater in tubes planted with the 'Tainung 01' variety, which developed smaller root systems and lower stomatal conductance than 'Sunrise Golden' seedlings. The highest values for shoot dry weight and WEU were obtained at 6.0 kPa STI for 'Sunrise Golden' (0.62 g and 0.69 g L-1) and at 9.0 kPa in 'Tainung 01' (0.35 g and 0.82 g L-1). RWC at 9.0 kPa STI was lower than at 3.0 kPa in both varieties. The results indicate that the low-cost technology developed for irrigation automation is promising. Even so, new studies are needed to evaluate low-flow irrigation systems as well as the nutrient and water needs of different papaya varieties.
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Benz, J. S., E. R. Keller, and D. J. Midmore. "Planting materials for warm tropic potato production: production and field performance of nursery-produced tubers." Journal of Agricultural Science 127, no. 1 (1996): 67–81. http://dx.doi.org/10.1017/s0021859600077388.
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SUMMARYPotato production in the lowland tropics is constrained by lack of affordable supplies of planting material. Therefore, the potential to produce in situ tuber seed from true potato seed (TPS) seedlings and rooted stem cuttings under nursery conditions in the warm tropics was studied, and their yields were compared with those of the same materials obtained under cool conditions. Subsequently, their field performance in the warm tropics was evaluated.Tuber yield from TPS seedlings and rooted cuttings transplanted in nursery beds under warm conditions ranged from 50% to < 20% of that obtained in cool conditions, but reductions in tuber numbers were less marked under warm conditions. Survival of seedlings was less than that of stem cuttings, but tuber numbers of seedlings exceeded those of rooted cuttings by a factor of two or more (e.g. 700 m−2 for seedlings v. 224 m−2 for rooted cuttings). Low tuber number is physiologically inherent in cuttings, as is high tuber number in seedlings. Total tuber yields varied significantly amongst clones grown in the warm climate from rooted cuttings, not always in proportion to the number of tubers produced. Differences in tuber yield and tuber number were less marked between the two TPS progenies studied.The field comparisons highlighted the 30–40% lower yield potential for warm-climate-produced nursery seed materials. Slower emergence and fewer stems apparently were in part responsible for this effect; however, neither tuber number harvested nor the proportion of marketable tubers was affected by site of production of seed materials. Cutting medium-sized warm-produced tubers (mean 23 g), the use of larger sized whole tubers (10–20 g v. 5–10 g) or increasing the planting density of 5 g tubers from 8·8 to 15·5 plants m-2 significantly increased yields by 4·9, 2·25 and 3·5 t ha-1, respectively, but yields were not increased further by 20–40 g tubers nor by 22·2 plants m-2. Small seedling tubers (≤ 5 g) can potentially lead to high stem numbers per unit weight of tubers, but their success in plant establishment was hampered in warm climates, especially in the presence of soil pathogens. Cool-climate-produced seedling tubers and tubers from cuttings can compete physiologically with field-produced seed tubers when used as planting materials in the warm tropics. However, with few exceptions, no crop from tubers produced under warm conditions could match the performance of crops from similar cool-produced tubers when planted out in the warm tropics.
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Asiegbu, F. O., M. Kacprzak, G. Daniel, M. Johansson, J. Stenlid, and M. Mañka. "Biochemical interactions of conifer seedling roots with Fusarium spp." Canadian Journal of Microbiology 45, no. 11 (1999): 923–35. http://dx.doi.org/10.1139/w99-099.
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The importance of root and spore surface molecules in the interactions of Fusarium spp. with conifer roots, and cellular localization of proteins presumed to be involved in host defence, were investigated. For adhesion studies, using a combination of fluorescein isothiocyanate (FITC) labelled lectins and high perfomance liquid chromatography (HPLC), several sugars (pinitol, xylitol, galactose, mannose, and glucose) were detected in root surface mucilage. Both artificial substrata and detached living roots were used to evaluate the significance of selective removal of root or spore surface components on the adhesion process. The spores or roots were pretreated with either periodic acid, pronase E, potassium hydroxide or diethyl ether. Pretreatment of the spores with diethyl ether reduced significantly the level of spore adhesion, which suggests that the adhesive component is either a lipid, or is bound to lipid. Since oxidation of carbohydrate reactive sites with periodic acid on the root surface almost completely abolished the development of germ tubes by adherent spores, it was presumed that some of these periodate-sensitive substances serve as a nutrient source for the fungus. On inoculated roots, F. avenaceum and F. culmorum were significantly pathogenic to both Norway spruce and Scots pine seedlings. Cytochemical labelling of sites of accumulation of host defence molecules within infected root tissues using anti-peroxidase demonstrated increased peroxidase activity in host cell walls. With anti-chitinase and anti-glucanase, gold labelling was found mainly on pathogen hyphal walls.Key words: conifer seedlings, adhesion, Fusarium spp., PR proteins, immunolocalization, lectins.
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Muriuki, Jonathan K., Anne W. Kuria, Catherine W. Muthuri, Athanase Mukuralinda, Anthony J. Simons, and Ramni H. Jamnadass. "Testing Biodegradable Seedling Containers as an Alternative for Polythene Tubes in Tropical Small-Scale Tree Nurseries." Small-scale Forestry 13, no. 2 (2013): 127–42. http://dx.doi.org/10.1007/s11842-013-9245-3.
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Amgai, Resham Babu, Hari Kumar Prasai, and Yama Raj Pandey. "Hormonal Effect on Mandarin Orange (Citrus reticulata Blanco) Micro-propagation." Nepal Journal of Biotechnology 4, no. 1 (2016): 33–36. http://dx.doi.org/10.3126/njb.v4i1.16344.
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Tissue culture is the best option to produce disease free seedling of the fruit crop rapidly. Micro-propagation and use of the in-vitro grafting (micro-grafting) is very helpful for production of virus free planting materials in mandarin. Different levels of the in-vitro hormone affect the success of callusing, shooting and plant regeneration in mandarin. Shoot bud, flower bud and in-vitro seedling epicotyl was used as explants to study the hormonal effect on mandarin micro-propagation. Similarly, 10 levels of BAP and IAA combination on MS media for mandarin tissue culture were used. Observation was done for 100 test tubes per treatment combination after 4, 8 and 12 weeks of culture. Data was arc sine transformed for analysis. Shooting from explants was significantly higher (71.72%) on medium level of the BAP (0.5 mg/L) and IAA (0.2 mg/L) using in-vitro seedling stem as explant, however, it was 27.91% for stem bud as explant. Stem bud showed higher level of callusing (6.15%, p<0.001) in mandarin orange. However, flower bud didn’t develop shoot in mandarin tissue culture. Increment of the in-vitro regeneration of the shooting and callusing was observed by the increment of the in-vitro incubation duration in mandarin orange tissue culture.
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Gabira, Monica Moreno, João Felipe Penteado Gomes, Dagma Kratz, Ivar Wendling, and Carlos André Stuepp. "Industrial residues as substrate components for the production of Ilex paraguariensis seedlings." Comunicata Scientiae 11 (August 24, 2020): e3215. http://dx.doi.org/10.14295/cs.v11i.3215.
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Ilex paraguariensis is an important forest species in Brazil. Recently, the development of new products has increased seedlings demand and consequently, the interest in new products to use as substrates like residues from industries. We aimed to evaluate the viability of using industrial residues as substrates to produce yerba mate seedlings. We formulated thirteen substrates with coconut fiber, carbonized and decomposed yerba mate industrial residues in different ratios, which were compared to two commercial substrates, in a completely randomized design. The stratified seeds were placed in 110 cm³ tubes filled with the substrates. Plants were kept in a greenhouse for 135 days, shade house (70%) for 30 days, and rustification area in full sunlight for 15 days, under fertigation after 30 days of sowing. We evaluated montlhy the survival, height, and stem diameter, and at the end of the production period, we evaluated shoot and root dry mass. From the data obtained, we calculated the total dry mass and ‘Dickson quality index’. The substrates formulated with coconut fiber and decomposed yerba mate industrial residue can be used to produce yerba mate seedlings, but it depends on the ratio of the substrate components. Substrates with higher total porosity and microporosity provided seedlings with biometric characteristics similar to those produced in commercial substrates. The carbonized yerba mate residue reduced seedling growth when used in a percentage equal to or higher than 50% in the substrate.
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Mendonça, Victória Maria Monteiro, Marcos Gervasio Pereira, Vitória Duarte S. Silva, Ariovaldo Machado Fonseca Júnior, Sidinei Júlio Beutler, and Tiago Paula Silva. "CHARACTERIZATION AND USE OF SUBSTRATES COMPOSED OF ORGANIC WASTE IN THE PRODUCTION OF Colubrina glandulosa PERKINS SEEDLINGS." FLORESTA 51, no. 2 (2021): 381. http://dx.doi.org/10.5380/rf.v51i2.69177.
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Urban organic waste has been gaining prominence in the composition of substrates, as it is a source of natural nutrients and a sustainable alternative to mitigate environmental impacts caused by improper waste disposal. The aim of this study was to characterize chemically and physically substrates based on organic waste and to evaluate the development of Colubrina glandulosa seedlings using composted urban tree pruning waste. Treatments consisted of different proportions of organic compost (CP), soil from the A horizon (SAH), aged manure (BM) and vermiculite, kept in tubes (Citropote®) with volume of 1.7 L. C/N ratio, water holding capacity (10 hPa), electrical conductivity, macroporosity, microporosity and total porosity of substrates before their use were determined. Substrate fertility analyses were carried out before and after seedling production. During the development of the seedlings, height (H) and stem diameter (SD) were measured at 60, 90 and 120 days. At 90 and 120 days, the seedlings were divided into shoots and roots to determine the dry mass of each compartment, Dickson quality index (DQI) and contents of nutrients (N, P, K, Ca and Mg). After the analysis of the results, it can be observed that the treatments with high proportions of CP had better physical characteristics, but also showed chemical limitation in the development of the seedlings. Treatments based on BM, SAH and lower proportion of CP had the highest average results for H, SD, H/SD ratio and DQI.
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Ribeiro, Márcia de Nazaré Oliveira, Moacir Pasqual, Fabíola Villa, Leila Aparecida Salles Pio, and Henk William Maria Hilhorst. "In vitro seed germination and seedling development of Annona crassiflora Mart." Scientia Agricola 66, no. 3 (2009): 410–13. http://dx.doi.org/10.1590/s0103-90162009000300017.
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Annona crassiflora Mart known as 'araticum', 'marolo' or 'field araticum' is a typical fruit from the Cerrado biome of Brazil with socio-economic and medicinal importance. Normally, Annona crassiflora is propagated through seeds. However, due to a deep dormancy that the seeds display at dispersion and the difficulty to obtain uniform plants in a short time period, micropropagation may be a feasible alternative. Concentrations of gibberellic acid (GA3) and naphthalene-acetic acid (NAA) and their interactive effects on in vitro seed germination and seedling development of Annona crassiflora were studied. Mature fruits of Annona crassiflora were depulped and the seeds washed in clear water and dried at room temperature. Seed coat was removed and the seeds were placed on Murashige & Skoog (MS) medium supplemented with gibberellic acid (GA3) and naphthalene-acetic acid (NAA), 30 g L-1 sucrose and 6 g L-1 agar-agar. Seeds were kept under these conditions for 30 days. After this period, seedlings were kept for another 90 days on Wood Plant Medium (WPM) with 20 g L-1 sucrose and 5 g L-1 agar-agar supplemented with the same GA3 and NAA concentrations. Cultures were incubated under controlled conditions at 25 ± 2°C temperature, 16: 8 (light: dark) photoperiod of 32 µmol m-2 s-1 irradiance provided by cool white fluorescent tubes (Philips). Use of WPM medium supplemented with 25-32 mg L-1 GA3 or MS with 26-30 mg L-1 GA3 and 2 mg L-1 NAA promoted rooting and plant growth.
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PINHEIRO, EDUARDO MENDONÇA, CAMILA PINHEIRO NOBRE, THAYANNA VIEIRA COSTA, ORLANDO CARLOS HUERTAS TAVARES, and JOSÉ RIBAMAR GUSMÃO ARAUJO. "ARBUSCULAR MYCORRHIZAL FUNGI IN SEEDLING FORMATION OF BARBADOS CHERRY (Malpighia emarginata D.C.)." Revista Caatinga 32, no. 2 (2019): 370–80. http://dx.doi.org/10.1590/1983-21252019v32n210rc.
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ABSTRACT The use of beneficial microorganisms such as arbuscular mycorrhizal fungi (AMF) may favor both the growth phase and the stabilization of the seedlings after transplantation. The aim of this study was to evaluate the effect of inoculation of different AMF species on the development of Barbados cherry seedlings from herbaceous and semi-hardwood cuttings. Softwood and semi-hardwood cuttings, previously rooted, were planted in 500 ml tubes filled with Plantmax® substrate and inoculated with three species of mycorrhizal fungi (Gigaspora margarita - Gimarg, Claroideoglomus etunicatum - Claetun and Glomus clarum - Glclar) isolated and combined (Gimarg + Claetun, Gimarg + Glclar, Claetun + Glclar and Gimarg + Claetun + Glclar). The statistical design was completely randomized in factorial scheme 2 x 8 (two types of cuttings and eight types of inoculation, including control without AMF inoculation) with ten replications. The seedlings were kept in a greenhouse for 100 days and height was measured every 15 days to determine the absolute and relative growth rate (AGR and RGR). At the end of the experiment the seedlings were sacrificed and determined height, fresh and dry shoot mass and root and mycorrhizal colonization rate. The results indicate potential for production of Malpighia emarginata D.C. seedlings inoculated with AMF with tendency to reduce the time for transplanting. The Gimarg + Claetun combination promoted higher rates of absolute growth and height of seedlings from herbaceous cuttings. The species Glomus clarum, isolated or associated with C. etunicatum, promoted higher colonization rates in herbaceous and semi-hardwood seedlings, respectively.
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Bezerra, Marlene Alexandrina Ferreira, Walter Esfrain Pereira, Francisco Thiago Coelho Bezerra, Lourival Ferreira Cavalcante, and Sherly Aparecida da Silva Medeiros. "Nitrogen as a mitigator of salt stress in yellow passion fruit seedlingss." Semina: Ciências Agrárias 40, no. 2 (2019): 611. http://dx.doi.org/10.5433/1679-0359.2019v40n2p611.
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The poor chemical quality of water, especially in arid and semiarid regions, almost always precludes the practice of irrigated agriculture, thus demanding the adoption of techniques that mitigate the deleterious effects of excess salt on soil and plants. The aim of this research was to evaluate the effectiveness of nitrogen fertilization in mitigating the negative effects of excess salt in irrigation water on the growth of yellow passion fruit seedlings grown in a greenhouse in plastic tubes containing 0.65 dm3 of substrate. The treatments were organized in randomized blocks, in accordance with a 5 × 3 factorial scheme – five electrical conductivities of irrigation water (0.3, 1.0, 2.0, 3.0, and 4.0 dS m?1) combined with three levels of nitrogen fertilizer (no nitrogen fertilization and 150 mg dm?3 of N derived from either ammonium sulfate or urea). Evaluations were performed 80 days after sowing and consisted of measuring the seedling height, stem diameter, number of leaves, leaf area, leaf nitrogen content, leaf concentration of chlorophyll a and b and total chlorophyll, specific leaf area, leaf area ratio, and Dickson quality index. An increase in the electrical conductivity of irrigation water hindered the production of yellow passion fruit seedlings. Nitrogen fertilization, with urea or ammonium sulfate, mitigated the effects of irrigation water salinity and favored the growth and quality of yellow passion fruit seedlings. Yellow passion fruit seedlings with a minimum quality standard (DQI) can be produced with irrigation water with salinity of 1.8 dS m?1, which means they can be considered as moderately sensitive. The higher quality provided by nitrogen to the yellow passion fruit seedlings made them more tolerant to salinity, allowing the use of water with salinity of 2.1 and 2.5 dS m?1 under fertilization with ammonium sulfate and urea, respectively.
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Panizzi, A. R., and T. Lucini. "Body position of the stink bug Dichelops melacanthus (Dallas) during feeding from stems of maize seedlings." Brazilian Journal of Biology 79, no. 2 (2019): 304–10. http://dx.doi.org/10.1590/1519-6984.18250.
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Abstract The Neotropical green-belly stink bug, Dichelops melacanthus (Dallas) is a major pest of maize, Zea mays L. in the main production areas of Brazil. It usually feeds on the stems of young plants (seedlings) causing heavy damage by affecting the plant growth and mitigating seed yield. Laboratory studies were conducted to determine body position (upward or downward) of the bug on plant (seedling) stem during feeding and not feeding activities. Ten visual records were taken per day, each spaced one hour during 30 days of 10 adult bugs of similar age exposed to maize seedlings inside cages (plastic tubes). At each observation, it was recorded if the bug was feeding on the stem (i.e., stylets inserted into the plant tissue) or not, and its body position. During feeding, waveforms were recorded using the EPG (electropenetrography) technique, which were correlated with histological studies to reveal the feeding sites. Results indicated that when they were feeding, the majority of the bugs were in the downward position. In contrast, when the bugs were on the plants, and not feeding, they were mostly in the upward position. Waveforms generated using the EPG coupled with histological studies demonstrated that during ingestion bugs fed from the xylem vessels and from the parenchyma tissue using cell rupture strategy in the latter. No clear explanation was found to explain the preferred downward body position during ingestion, but some hypothesis are speculated.
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Ben-Zeev, Shiran, Shane Kerzner, Onn Rabinovitz, and Yehoshua Saranga. "Optimizing Sowing Depth of Tef for Irrigated Mediterranean Conditions: From Laboratory to Field Studies." Agronomy 10, no. 12 (2020): 1983. http://dx.doi.org/10.3390/agronomy10121983.
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Developing new crops adapted to arid conditions is a promising approach to meet the increasing demand for food production under expanding aridity. Tef [Eragrostis tef (Zucc.) Trotter] is a C4 cereal crop cultivated mainly in Ethiopia and the Horn of Africa, and known for its high resilience to stressful environments. Due to their tiny size, tef seeds are traditionally sown by broadcasting and lightly covering with soil. Under semiarid Mediterranean conditions, a deeper sowing may guarantee seedling establishment while saving on irrigation water. The objective of this study was, therefore, to determine the effects of sowing depth on tef emergence, development, lodging, and productivity. Tef seeds were sown at different depths in test tubes and pots, and in two field experiments. In tubes and pots, time from sowing to emergence increased about twofold and emergence rate decreased in the deepest sowing (3 cm) treatment compared to controls (0 cm). In the pot and field trials, deep sowing (3 cm) significantly reduced plant height, shoot and root biomass, and lodging. Sowing depths of 1–2 cm allowed successful plant establishment while not exacting penalties on plant emergence or development; hence this range appears to be optimal for sowing irrigated tef.
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Kratz, Dagma, Antonio Carlos Nogueira, Ivar Wendling, and Paulo Vitor Dutra De Souza. "SUBSTRATOS RENOVÁVEIS PARA PRODUÇÃO DE MUDAS DE Mimosa scabrella." FLORESTA 45, no. 2 (2014): 393. http://dx.doi.org/10.5380/rf.v45i2.31249.
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Objetivou-se neste estudo avaliar a viabilidade técnica de substratos renováveis à base de fibra de coco, casca de arroz carbonizada em diferentes granulometrias, biossólido e casca de pínus semidecomposta para a produção de mudas de Mimosa scabrella. Para tanto, foram formulados 41 tratamentos, contendo como testemunha substrato comercial à base de casca de pínus, os quais tiveram suas propriedades físicas e químicas avaliadas. Realizou-se semeadura direta em tubetes de 55 cm³, permanecendo por 120 dias em estufa de vidro e 30 dias na área de pleno sol. Observou-se que o substrato comercial à base de casca de pínus e substratos com diferentes combinações de casca de arroz carbonizada e fibra de coco apresentaram-se viáveis para produção de mudas de M. scabrella, enquanto que o componente biossólido mostrou-se inviável. O peneiramento da casca de arroz não se justifica, quando comparado com a casca de arroz carbonizada na sua forma íntegra. Quanto menor a agregação do substrato às raízes, maior a facilidade de retirada das mudas dos tubetes. A densidade, matéria orgânica, pH, condutividade elétrica, salinidade e concentração de magnésio e fósforo influenciaram no crescimento das mudas.Palavras-chave: Bracatinga; biossólido; casca de arroz carbonizada; fibra de coco; propriedades físicas. AbstractRenewable substrates in the seedling production of Mimosa scabrella. The objective of this study was to evaluate the technical feasibility of renewable-based substrates coconut fiber, rice hulls at different grain sizes, sludge and pine bark semi-decomposed for the production of seedlings of M. scabrella. To this end, 41 treatments were formulated, containing commercial substrate as a control the base of pine bark, where they were which were analyzed in relation to their physical and chemical properties. Held tillage in plastic tubes of 55 cm³ for 120 days in a greenhouse of glass and 30 days in the full sun. It was observed that the commercial substrate based on pine bark and the substrates based on different combinations of rice hulls and coconut fiber showed to be viable for production of seedlings of M. scabrella, while the component biosolid had to be unfeasible. Screening of rice husk is not justified when compared with the rice hulls in its entirety. The lower the aggregation in substrate, the easier removal of the seedlings of the tubes. The density, organic matter, pH, electrical conductivity, salinity, magnesium and phosphorus influenced the growth of seedlings.Keywords: Bracatinga; biosolid; rice hulls; coconut fiber; physical properties.