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1
Kulla, L., J. Tutka, and R. Marušák. "Forest yield index and its applicability to the assessment of future forest yields." Journal of Forest Science 55, No. 1 (2009): 41–50. http://dx.doi.org/10.17221/45/2008-jfs.
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The paper suggests and examines a simplified relative indicator of forest production, with special regard to possibilities of its use in projecting future forests. Forest yield index (<I>I</I><sub>Y</sub>), based on an economic parameter “value of final cutting yield” was proposed, and examined in the model territory of Kysuce in north-western Slovakia. The current values of final cutting yield, dependent on tree species, site index and the length of rotation period served as a basis for the assessment of expected yields. The possibilities and limitations of index applicability in long-term strategic forest management decision-making are discussed, considering the uncertainty of ecological and economic conditions during the long forest production cycle, as well as the complexity of tree species growth and production in the mixed forests, uneven aged forests and forests under climate change.
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Suleiman, Nazeef, Idris Ado Yola, and Ibrahim Muhammad Ahmed. "Relative Yield Indices of Challawa Gorge Dam, Kano State, Nigeria." Greener Journal of Biological Sciences 7, no. 6 (2017): 60–62. https://doi.org/10.15580/GJBS.2017.6.111817167.
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Reservoir morpho-metrics and ionic input of Challawa dam, Kano State (Nigeria) were applied to estimate the potential fish yield using morpho-edaphic index (MEI). Physico-chemical parameters of the reservoir were sampled monthly from three stations (Feginma, Sakarma, and Turawa) for the period of six months (March to August, 2017) using standard methods. Potential fish yield estimates of the three sites were determined using the values of the Physico-chemical characteristics of the reservoir with the relationship Y=23.281 MEI <sup>0.447</sup>, where Y is the potential fish yield in Kg/ha, MEI is Morphoedaphic index (given in µS/cm) which was obtained by dividing mean conductivity of the reservoir by mean depth. The potential fish yield estimates of the three sites are 88.05, 98.56 and 111.12 Kg/ha. The relative yield index (RYI) which is the ratio of estimated yield with angler harvest, was determined using the relationship RYI= Y<sub>obs</sub>/Y<sub>est</sub> ×0.75, where Y<sub>est</sub> is estimated potential yield in kg/ha and Y<sub>obs</sub> is anglers harvest in Kg. The anglers were 53.3, 65.7 and 57.05 Kg respectfully, which implied that the relative yield indices were 44.5%, 49.9% and 38.5%. The results of this study showed that, the reservoir’s exploitation level was moderate (RYI≤1). Good ionic content, good dissolved oxygen levels, good pH, low-levels of pollution, accounted for the high estimates of the fish yield. Therefore effective management system, implementation of good fishing regulations and practices should be implemented.
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Nishizono, Tomohiro, Akio Inoue, and Kazuo Hosoda. "Relationship between relative yield index and relative spacing index : theoretical derivation of the relationship and its characteristics." Japanese Journal of Forest Planning 47, no. 1 (2013): 16–28. http://dx.doi.org/10.20659/jjfp.47.1_16.
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Kumari, Dewanshi, M. A. Davara, K. B. Ranpariya, and J. V. Polara. "Relative RSC tolerance of groundnut." INTERNATIONAL JOURNAL OF AGRICULTURAL SCIENCES 18, no. 2 (2022): 813–14. http://dx.doi.org/10.15740/has/ijas/18.2/813-814.
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A pot experiment was conducted during summer-2019 to evaluate four varieties of groundnut with four RSC level of irrigation water, A0, A1, A2 and A3 - 0, 2.5, 5.0 and 7.5 meq L-1, respectively, at Department of Agricultural Chemistry and Soil Science. Junagadh Agricultural University, Junagadh. The pod yield of different varieties of groundnut significantly decreased with increasing in the RSC levels of irrigation water. Among the different varieties of groundnut, variety TPG-41 gave highest pod yield (8.41 g pot-1) at RSC level of 0 meq L-1 of irrigation water. The variety TPG-41 recorded highest mean pod yield (7.82 g pot-1), mean salinity index (92.96 %) minimum yield reduction (11.72) at high RSC levels (7.5 meq L-1) and 50 % yield decline at 30.40 meq L-1.
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POURMOHAMMAD, Azam, Mahmoud TOORCHI, Seyed S. ALAVIKIA, and Mohammad R. SHAKIBA. "Genetic Analysis of Yield and Physiological Traits in Sunflower (Helianthus annuus L.) under Irrigation and Drought Stress." Notulae Scientia Biologicae 6, no. 2 (2014): 207–13. http://dx.doi.org/10.15835/nsb629173.
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Implementing appropriate breeding strategies for sunflower, alongside dependable information on heritability and gene effects upon yield and related traits under drought conditions, are all necessary. Thirty sunflower hybrids were produced by line × tester cross of six male-sterile and five restorer lines. Their hybrids were evaluated in three levels of irrigation, as follows: (1) non-stressed plots, irrigated at regular intervals (W1); (2) mild water stress (W2), irrigated from the beginning of the button stage (R4) to seed filling initiation (R6); (3) severe water stress (W3) started from the beginning of button stage (R4) to physiological maturity. Based on observations and specific methods for determination, canopy temperatures, chlorophyll index, relative water content and proline content, were studied by additive effects, under the different irrigation conditions. Canopy temperatures,chlorophyll index, relative water content, leaf water potential, proline content and yield were controlled by additive effects under mild stressed conditions. Under severe stress conditions however, canopy temperatures, leaf water potential and proline content were controlled by additive effects, while chlorophyll index and relative water content were controlled by both additive and dominant effects, as seed yield was mainly influenced by the dominant effects. The narrow sense heritability ranged from 47-97% for all traits, except for chlorophyll fluorescence. Yield correlated positively with chlorophyll index and relative water content, and negatively with canopy temperature and leaf water potential. Therefore, under drought stressed conditions in breeding programs, canopy temperatures, chlorophyll index and relative water content can be reliable criteria for the selection of tolerant genotypes with prospect to higher yields.
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Hussain, Mohammed, Hajer Askandar, Abbas Khether, and Rezgar Saaed. "Evaluation Maize Genotypes for Yield and Yield Components and Constructing Selection Index." Tikrit Journal for Agricultural Sciences 19, no. 4 (2023): 76–82. http://dx.doi.org/10.25130/tjas.19.4.10.
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This experiment was conducted at farm of field crops department, collage of agriculture, Duhok University in spring 2018 to construct selection index. The results showed that all selection indices include the yield gave relative efficiency equal to those when used the yield only, the increase in efficiency was very low and not important, selection index was a few relative efficiency as a compered with efficiency index which include the yield, therefore, the best selection index was depend on the yield only to select the better indices and some variance components to twenty maize genotypes according to Randomize Complete Block Design with three replication, also the result exhibited that the GCVwas medium for all characters except grain yield while, the PCV was high for grain yield, ear height and 300 grain weight and medium for the rest characters. The GAM gave high values for grain yield, plant and ear height and leaf area, the value range between 22-40 while the others characters showed medium values. On other hand the results showed high heritability broad sense ranged from %80 to %99 for all characters except 300- grain weight.
 
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de la Torre, Daniel. "Relative Yield Loss Calculations in Wheat (Triticum durumDesf. cv. Camacho) due to Ozone Exposure." Scientific World JOURNAL 10 (2010): 103–15. http://dx.doi.org/10.1100/tsw.2010.26.
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In this work, an estimation of the relative yield losses of wheat due to ozone exposure is made by means of two approaches proposed by the CLRTAP (Convention on Long Range Transboundary Air Pollution): the exposure-response approach, which deals with the exposure of plants to ozone during a certain time, and the accumulated uptake approach, which, besides ozone exposure, deals with the velocity of absorption of the contaminant and the environmental factors that modulate that absorption. Once the relative yield losses are calculated by means of the two approaches, the aim is to establish which index (the exposure-response index or the accumulated uptake index) best characterizes the response of wheat plants to ozone. The relative yield losses are compared considering two watering regimes: well watered and nonwatered. The results obtained show that the relative yield losses in wheat due to ozone exposure are much more strongly linked to the real quantity of ozone absorbed by plants than to the environmental ozone exposure, which means that the accumulated uptake approach is much more realistic than the exposure-response approach. Relative yield loss estimations were higher in a crop with no watering; 3% of relative yield losses more than a crop watered until field capacity.
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Andleeb, Tayyaba, Zeshan Ali, Zahid Mahmood, Sadia Latif, and Umar Masood Quraishi. "Wheat Varietal Response to Relative SPAD Index (RSI) and Relative Normalized Difference Vegetation Index (RNDVI) under Variable Nitrogen Application and Terminal Heat Stress along with Yield Repercussion." Agronomy 12, no. 7 (2022): 1538. http://dx.doi.org/10.3390/agronomy12071538.
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Nitrogen (N) deficiency and heat stress (HS) are major abiotic stresses that affect the quantity and quality of wheat grains. This study was conducted to examine wheat varietal response to RSI and RNDVI at the anthesis stage and their relationship to yield and yield-related traits under variable N supply and terminal heat stress. Twelve wheat varieties were evaluated in 2016–2017 and 2017–2018 at the National Agricultural Research Centre (NARC), Islamabad, Pakistan. The experiment was divided into three sets, i.e., N120 (120 kg N/ha), N60 (60 kg N/ha) and N0 (0 kg N/ha), based on the nitrogen fertilizer application. The physiological and yield-related parameters were recorded. Mean grain yield for all twelve varieties, averaged from two years of data, ranged between 1655.0 and 3890.1 kg/ha. Maximum RSI (0.99), RNDVI (1.03) and GY (3890.9 kg/ha) were recorded for FSD-08, while AARI-11 showed minimum RSI (0.50), RNDVI (0.56) and GY (1396.40 kg/ha). In the present study, mean CTD was lower, at N0 (3.57 °C), followed by N60 (5.07 °C) and N120 (5.47 °C) on average for the two years of data. The strong positive correlation of RSI and RNDVI with grain yield at R2 = 0.73 and R2 = 0.49 suggest that these parameters can be used as efficient and precise selection criteria for identifying nitrogen-use-efficient wheat varieties under terminal heat-stress conditions. This work will help the researchers to identify and develop nitrogen-use-efficient and thermos-tolerant wheat cultivars by minimizing the negative impacts of heat stress at the anthesis stage.
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Kowalenko, C. G. "An evaluation of estimating and indexing methods to simplify the determination of management treatment effects on raspberry yields." Canadian Journal of Plant Science 83, no. 1 (2003): 141–47. http://dx.doi.org/10.4141/p02-060.
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The effectiveness of using several proposals to estimate or index yield and size of raspberries as an alternative to picking berries as they ripen was examined in two field plot trials over two seasons at two locations in south coast British Columbia. The evaluation included examination of general correlations of the proposed estimate and index values with fresh picked yield, comparison of the significant nutrient and inter-row management treatment effects on proposed method values with effects on fresh picked yield values, influence of individual cane variability to distinguish significant treatment effects, and the effect of N on plant components used to derive the estimate and index method. Correlation coefficients for all yield estimate and index method values with fresh picked yields were generally good. Crop management treatment effects determined by the estimate and index values, however, were not the same as determined by harvesting the berries as they ripened. This showed that the estimate and index method values were biased relative to picked yield. Cane-to-cane variability within individual treatment plots was sufficiently large that differences between treatments had to be greater than 10 to 15% to be significant at P < 0.05 when five canes were randomly sampled for index component measurements to represent the plants in the plot. The five canes sampled for each plot were 5 to 10% of all the floricanes in the plots of this study. The concentration and biomass N measurements that were possible on the floricane components that were sampled for the index methods showed that management treatments of the two trials of the study could have influenced berry development, and hence contributed to the bias of the estimate and index method values relative to fresh picked yield. Although the estimate and index methods were generally quite well correlated with fresh picked yield, caution is advised when they are used directly as alternatives to fresh picking to evaluate crop management treatment effects on berry yield. Further knowledge about the physiological changes that occur during berry ripening may provide opportunities to improve the estimate and index measurements. Key words: Raspberry, Rubus idaeus L., yield estimate, yield index, nutrient effects, nitrogen effects
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Ahmed, Sheikh Faruk, Anika Nazran, Totan Kumar Ghosh, Jalal Uddin Ahmed, and Mohammed Mohi Ud Din. "Screening drought-tolerant bread wheat genotypes using yield-based stress indices." Annals of Bangladesh Agriculture 27, no. 2 (2023): 41–58. http://dx.doi.org/10.3329/aba.v27i2.72517.
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Global wheat (Triticum aestivum L.) productivity suffers severely from drought stress. Exploiting natural variation in drought tolerance among genotypes offers a promising avenue to counter yield losses and breed superior varieties. As yield is the key trait in wheat breeding, selecting genotypes based on both yield and drought tolerance indices remain a viable strategy. To identify tolerant genotypes using yield and yield-based indices, a comprehensive investigation was conducted in a factorial fashion of 56 wheat genotypes under two water regimes (control and drought) over two distinct growing years. This approach employed a split-plot design to ensure the statistical robustness of the results. Drought stress significantly reduced grain yield regardless of genotype or growing season. Strong correlations were observed between yields and yield-based drought tolerance indices, with most associations being strongly positive for both control and drought-stressed conditions. Both hierarchical cluster analysis and principal component analysis produced well-correlated results, revealing three distinct genotypic clusters: 6 tolerant and high-yield, 31 mid-tolerant, and 19 susceptible and low-yield genotypes. Statistical analysis showed that eight drought tolerance indices, viz. stress tolerance index (STI), modified stress tolerance index (mSTI), mean productivity (MP), geometric mean productivity (GMP), harmonic mean index (HMI), relative efficiency index (REI), relative decrease in yield (RDY), and superiority index (Pi) effectively distinguished the genotypic clusters, indicating their usefulness in selecting drought-tolerant and high-yielding wheat genotypes. The genotypes from the tolerant cluster: BARI Gom 33, BARI Gom 21, BAW-1147, BD-9910, BD-600, and BD-9889 exhibited better yield protection under drought stress compared to the other genotypes, demonstrating their potential for cultivation in water-deficit environments. Ann. Bangladesh Agric. (2023) 27 (2): 41-58
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Pallavi, M., P. Shanthi, VLN Reddy, AR Nirmal Kumar, and BP Maruthi Prasad. "Selection index for enhanced yield in rice genotypes." Oryza-An International Journal on Rice 61, no. 2 (2024): 176–82. http://dx.doi.org/10.35709/ory.2024.61.2.10.
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Plant breeding heavily relies on artificial selection to enhance grain yield through various contributing traits. The challenge in selecting complex quantitative traits, such as rice grain yield, lies in low heritability and a significant influence of environmental factors. This study involved 42 rice genotypes with the aim of identifying yield-contributing traits and establishing simultaneous selection models based on discriminant functions. The anticipated genetic gain for grain yield, when all the studied traits were considered in simultaneous selection, was notably higher (445.69%) compared to selecting grain yield alone (13.35%). The discriminant function comprised five traits: plant height (X1), number of filled grains per panicle (X4), number of grains per panicle (X5), seedling vigour index (X6), and grain yield per plant (X7). This combination exhibited a substantial genetic advance of 435.87% and a remarkable relative efficiency of 3264.05%. The relative efficiency of selection, considering grain yield alone, was set at 100%. However, when six ((X1, X3, X4, X5, X6, and X7) and seven traits were simultaneously considered, the efficiency increased to 3044.338 and 3337.606, respectively. Based on the ideal discriminant function, MTU3626 emerged as the best genotype with the highest selection score of 1706.046, followed by SM227 (1669.16) and NDP3 (1555.33). Conversely, MTU1010 ranked last with a selection score of 765.076.
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Odey, Simon O., and Seth I. Manuwa. "Influence of Cone Index on Mean Relative Growth Rate, Leaf Area Index and Yield of Soybean in Sandy Clay Soil." European Journal of Advances in Engineering and Technology 5, no. 8 (2018): 581–88. https://doi.org/10.5281/zenodo.10716122.
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<strong>ABSTRACT</strong> Mean Relative Growth Rate (MRGR), Leaf Area Index (LAI) and yield of soybean (varTGX-1448-2E) as affected by cone index in sandy clay soil was tested. Soil tests were carried out before and during the experiment. Penetrometer and moisture meter were used in measuring cone index and soil moisture content before and after treatments. The area was cleared and harrowed. Four treatments including a control were imposed on the land. A Mersey Fergusson – MF 275 Xtra2WD/4WD tractor with 75 Hp and 2,360 kg weight was used. The treatments were <strong>PLH</strong> = Ploughed and Harrowed- zero passes of tractor wheels (control), <strong>PLC<sub>10</sub></strong> = Ploughed, harrowed and compacted to10 passes of tractor wheels, <strong>PLC<sub>20</sub></strong> = Ploughed, harrowed and compacted to 20 passes of tractor wheels, <strong>PLC<sub>30</sub></strong> = Ploughed, harrowed and compacted to 30 passes of tractor wheels, These were replicated three times making a total of twelve subplots. The treatments and replications were laid in a Randomized Complete Block Design (RCBD). A soybean variety TGX-1448-2E was planted and parameters were measured at 2, 4, 6, 8, 10, 12, and 14 weeks after planting (WAP). Among the variables measured were plant height, width, number of leaves, leaf area, dry matter weight, and weight of threshed soybean. Analysis of the data revealed that the Leaf Area Index (LAI) of 42.83 was realised at cone index of 0.081 MPa. Thus the LAI reduced to 10.20 at cone index of 1.21 MPa. On the other hand Mean Relative Growth Rate (MRGR) of 79.66 was observed at cone index of 0.081 MPa. Whereas at 1.21 MPa, a MRGR of 59.29 was observed. While a MRGR of 52.36 was realised at cone index of 1.82 MPa. A yield of 2.50 t/ha was realised from soybean planted on <strong>PLH</strong> plots with an average cone index value of 0.081 MPa. Whereas at higher cone index value of 1.21 MPa, only 1.15 t/ha of soybean yield was realised. A strong negative correlation exists between cone index and growth, and yield variables. Thus correlation values of -0.906, -0.999, -0.983 exist for plant height, leaf area and yield of soybean respectively. It can be concluded that increase cone index of soil leads to reduction in MRGR, LAI and yield parameters of crops.
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Khare, Vikrant, R. S. Shukla, Suneeta Pandey, and Sanjay Singh. "Identification of Drought Tolerant Recombinant Inbred Lines and Estimation of Genetic Diversity by Clustering and Multivariate Analysis in Wheat RILs Populations." International Journal of Bio-resource and Stress Management 13, no. 5 (2022): 481–87. http://dx.doi.org/10.23910/1.2022.2924.
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The current experiments were carried out in alpha lattice design at the Seed Breeding Farm, Department of Plant Breeding and Genetics, Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur, Madhya Pradesh state, India, during 2019−20 and 2020−21 crop seasons, using 236 RILs population. The aim of current experiment is to assessment of genetic diversity and identification of promising recombinant inbred lines for irrigated and restricted irrigated conditions through PCA and cluster analysis. The drought selection indices viz. Relative drought index, yield stability index, drought resistance index, mean productivity, stress tolerance index and yield index were performed from two year grain yield pooled data. The principal component analysis and cluster analysis were performed through drought selection indices. Drought selection indices viz. relative drought index, yield stability index, yield index were confirm strong positively associated with grain yield under restricted irrigated conditions while mean productivity, stress tolerance index and yield index were strong positively associated with grain yield under irrigated conditions. Moreover, high cluster mean, for grain yield under restricted irrigated condition with associated selection indices was confirmed by 77 inbred lines from cluster I. similarly 128 superior inbred lines were found for irrigated condition. The highest inter cluster distance was observed between cluster I and cluster III therefore the inbred line occupy by cluster I and cluster III were considered as most diverse lines and could be used in farther breeding program to achieve more recombination for drought tolerance.
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M.S, UMA, VISWANATH D.P, and GURURAJA RAO M.R. "RELATIVE PERFORMANCE OF COTTON GENOTYPES UNDER DIFFERENT LEVELS OF SALINITY IN IRRIGATION WATERS." Madras Agricultural Journal 82, January (1995): 15–18. http://dx.doi.org/10.29321/maj.10.a01110.
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Seven genotypes of cotton were screened for tolerance to different levels of salinity in inigation water for four years. The genotypes showed significant variation in respect of mean kapas yield in all the four years. Further, the mean kapas yield decreased with increased salinity levels of imigation water. The slope of regression line was found to be inversely related to kapas yield, and, therefore, it offered a better criterion for appraisal of salinity tolerance. Based on mean salinity index, tolerance index value and the slope of regression line, MESR-17 and JK125-2-5 were identified as fairly tolerant genotypes to salinity.
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Stringer, Jeffrey W., and Stanley B. Carpenter. "Energy Yield of Black Locust Biomass Fuel." Forest Science 32, no. 4 (1986): 1049–57. http://dx.doi.org/10.1093/forestscience/32.4.1049.
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Abstract Detailed analysis of 2- to 10-year-old black locust (Robinia pseudoacacia L.) biomass components provided an accurate energy content and energy yield determination as well as an index defining a relative ceiling on the delivered cost for black locust biomass in comparison with other fuels such as coal and forest residues. Total energy content of individual biomass components ranged from 20.97 x 106 J kg-1 for leaf tissue to 19.23 x 106 J kg-1 for current years' growth. Annual total energy yields ranged from 33.75 to 76.79 x 109 J ha-1 yr-1 for 3- and 9-year-old stands, respectively. Nine-year-old stands also exhibited the highest annual net whole-tree and woody biomass (whole-tree less foliage) energy yields of 32.71 and 30.73 x 109 J ha-1 yr-1. The net annual energy yields were consistently greater for whole-tree biomass compared with woody biomass due to the foliage included in the whole-tree biomass. The relative cost indices maintained a high degree of variability between comparison fuels. Bituminous coal and forest residues were lowest with an overall mean cost index for woody biomass of $13.28 mt-1 and $13.72 mt-1, respectively. Woody biomass maintained a greater relative index than whole-tree biomass over all age classes due to its inherently higher conversion efficiency. Forest Sci. 32:1049-1057.
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Cattani, D. J., S. R. Smith, Jr ,. P. R. Miller, D. E. Feindel, and R. Gjuric. "Seed yield and yield components of creeping bentgrass cultivars." Canadian Journal of Plant Science 84, no. 1 (2004): 117–24. http://dx.doi.org/10.4141/p02-007.
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Creeping bentgrass (Agrostis stolonifera L.) is a high-value turfgrass species that offers opportunities for western Canadian seed companies and producers. The objective of this study was to evaluate creeping bentgrass seed yield and the relationship between seedhead density and seed yield across a diverse range of cultivars. A series of four trials was established in Manitoba between 1992 and 1994 and included 18th Green, Cobra, Emerald, National, Penneagle, Pennlinks, Putter, Southshore, UM86-01 and UM86-02. Seed production and seedhead density were measured for 2–3 yr at each location. Additional yield component measurements included harvest index and thousand seed weight. The three cultivars developed within the region consistently showed high seed yield, seedhead density and harvest index and were numerically ranked in the top four for seed yield across all 11 location years. UM86-01 was in the highest grouping for seed yield across all harvests with yields ranging from 312 to 582 kg ha-1. Seedhead density was strongly related to seed yield (highly significant in five of six comparisons) and therefore has the potential to be a valuable indicator of relative seed yield in creeping bentgrass. These results indicate that creeping bentgrass seed yield is variable across cultivars and that seedhead density can serve as a good predictor of seed production potential across cultivars. Key words: creeping bentgrass, harvest index, seedhead density, seed yield, yield components.
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Islam, MS, and MH Sohag. "Arsenic Stress Tolerance in Lentil Varieties." Bangladesh Agronomy Journal 24, no. 2 (2022): 13–20. http://dx.doi.org/10.3329/baj.v24i2.58005.
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A pot experiment was conducted inside a rain- shelter in the Department of Agronomy, Sher-e-Bangla Agricultural University, Dhaka in 2016 to evaluate the arsenic (As) stress tolerance of seven lentil varieties, viz., BARIMasur-1, BARIMasur-2, BARIMasur-3, BARIMasur-4, BARIMasur-5, BARIMasur-6 and BARIMasur-7 against three levels of arsenic stress viz., no arsenic stress (control), 25 mg As / kg soil and 50 mg As / kg soil. Arsenic treatment was imposed during pot filling with 10 kg air- dried soil pot-1. The pots were fertilized with 0.225 g urea, 0.425 g TSP and 0.175 g MoP pot-1 before seed sowing. Six healthy seeds of seven lentil varieties were sown in each pot and the plants were thinned to four after three weeks later. It was observed that increasing levels of As significantly decreased pods plant-1, 1000 seeds weight, seed yield, stover yield, harvest index and relative values of these parameters, whereas increased seed arsenic content and relative seed arsenic content in all the lentil varieties studied. Although BARIMasur-7, BARIMasur-6 and BARIMasur-5 gave the higher seed yield, their relative seed yield, relative values of yield components, relative stover yield and relative harvest index were lower, but seed arsenic content and relative seed arsenic content were higher compared to that of BARIMasur-1, BARIMasur-2, BARIMasur-3 and BARIMasur-4. Therefore, BARIMasur-1, BARIMasur-2, BARIMasur-3 and BARIMasur-4 varieties were superior and safe for consumption considering seed arsenic content and suitable for breeding considering relative seed arsenic content under soil arsenic stress conditions. Correlation studies indicated that As stress decreased relative seed yield by most negatively influencing the relative 1000 -seeds weight followed by relative pods plant-1, relative stover yield and relative seeds pod-1.
 Bangladesh Agron. J. 2021, 24(2): 13-20
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LAKSHMI, JHANSI, RAGHAVA REDDY C, and REDDY C.D.R. "INTER-RELATIONSHIP OF HARVEST INDEX,BIOLOGICAL YIELD AND OTHER METRIC TRAITS WITH GRAIN YIELD IN FOX-TAIL MILLET." Madras Agricultural Journal 81, February (1994): 80–81. http://dx.doi.org/10.29321/maj.10.a01315.
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Path analysis is one of the statistical approach to split the correlation coefficients into direct and indirect effects inorder to examine the relative contribution of the component characters. In the present study an attempt was made to understand the nature of inter-relationships among vairous parameters and grain yield and relative contribution of each of these traits to final built up of yield which is recognized interms of grain.
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Matsumoto, Shinichi, Hirofumi Noguchi, Nobuyo Hatanaka, et al. "SUITO Index for Evaluation of Efficacy of Single Donor Islet Transplantation." Cell Transplantation 18, no. 5-6 (2009): 557–62. http://dx.doi.org/10.1177/096368970901805-611.
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Evaluation of engrafted islets mass is important for clinical care of patients after islet transplantation. Recently, we developed the secretory unit of islet transplant objects (SUITO) index, which reflected engrafted islet mass. In this study, we evaluated the SUITO index for the prediction of clinical outcome after single islet transplantation. Single islet transplantations were performed into six type 1 diabetic patients. Isolated islets were quantitatively assessed at the time of transplantation. The SUITO index was calculated as follows: fasting C-peptide (ng/dl)/[fasting blood glucose (mg/dl) – 63] × 1500. Islet yield/recipient's body weight and SUITO index were evaluated, along with HbA1C, relative insulin dose (insulin dose posttransplant/pretransplant), and M-values. HbA1C improved in all cases, irrespective of the SUITO index score or islet yield/body weight. The average SUITO index from postoperative days 3 to 30 ( R2 = 0.728, p < 0.04), but not islet yield/body weight ( R2 = 0.259, p = 0.303), correlated with relative insulin dose. The daily SUITO index strongly correlated with the daily relative insulin dose ( R2 = 0.558, p < 0.0001) and weakly correlated with the daily M-values ( R2 = 0.207, p < 0.02). A SUITO index score of less than 10 was associated with increasing insulin dose even after islet transplantation. The SUITO index seems to be a better predictor of success of islet transplantations than islet yield/body weight. SUITO index is recommended to assess clinical outcome of islet transplantation.
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García-Martínez, Héctor, Héctor Flores-Magdaleno, Roberto Ascencio-Hernández, et al. "Corn Grain Yield Estimation from Vegetation Indices, Canopy Cover, Plant Density, and a Neural Network Using Multispectral and RGB Images Acquired with Unmanned Aerial Vehicles." Agriculture 10, no. 7 (2020): 277. http://dx.doi.org/10.3390/agriculture10070277.
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Corn yields vary spatially and temporally in the plots as a result of weather, altitude, variety, plant density, available water, nutrients, and planting date; these are the main factors that influence crop yield. In this study, different multispectral and red-green-blue (RGB) vegetation indices were analyzed, as well as the digitally estimated canopy cover and plant density, in order to estimate corn grain yield using a neural network model. The relative importance of the predictor variables was also analyzed. An experiment was established with five levels of nitrogen fertilization (140, 200, 260, 320, and 380 kg/ha) and four replicates, in a completely randomized block design, resulting in 20 experimental polygons. Crop information was captured using two sensors (Parrot Sequoia_4.9, and DJI FC6310_8.8) mounted on an unmanned aerial vehicle (UAV) for two flight dates at 47 and 79 days after sowing (DAS). The correlation coefficient between the plant density, obtained through the digital count of corn plants, and the corn grain yield was 0.94; this variable was the one with the highest relative importance in the yield estimation according to Garson’s algorithm. The canopy cover, digitally estimated, showed a correlation coefficient of 0.77 with respect to the corn grain yield, while the relative importance of this variable in the yield estimation was 0.080 and 0.093 for 47 and 79 DAS, respectively. The wide dynamic range vegetation index (WDRVI), plant density, and canopy cover showed the highest correlation coefficient and the smallest errors (R = 0.99, mean absolute error (MAE) = 0.028 t ha−1, root mean square error (RMSE) = 0.125 t ha−1) in the corn grain yield estimation at 47 DAS, with the WDRVI index and the density being the variables with the highest relative importance for this crop development date. For the 79 DAS flight, the combination of the normalized difference vegetation index (NDVI), normalized difference red edge (NDRE), WDRVI, excess green (EXG), triangular greenness index (TGI), and visible atmospherically resistant index (VARI), as well as plant density and canopy cover, generated the highest correlation coefficient and the smallest errors (R = 0.97, MAE = 0.249 t ha−1, RMSE = 0.425 t ha−1) in the corn grain yield estimation, where the density and the NDVI were the variables with the highest relative importance, with values of 0.295 and 0.184, respectively. However, the WDRVI, plant density, and canopy cover estimated the corn grain yield with acceptable precision (R = 0.96, MAE = 0.209 t ha−1, RMSE = 0.449 t ha−1). The generated neural network models provided a high correlation coefficient between the estimated and the observed corn grain yield, and also showed acceptable errors in the yield estimation. The spectral information registered through remote sensors mounted on unmanned aerial vehicles and its processing in vegetation indices, canopy cover, and plant density allowed the characterization and estimation of corn grain yield. Such information is very useful for decision-making and agricultural activities planning.
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Ila'ava, Vele P., Pax Blamey, and Colin J. Asher. "Effects of lime and gypsum on growth of sweet potato in two strongly acid soils." Australian Journal of Agricultural Research 51, no. 8 (2000): 1031. http://dx.doi.org/10.1071/ar00043.
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There were strong relationships between exchangeable aluminium (Al) and relative top yield, and between soil pH and relative top yield in the Garret and Bisinella soils. Sweet potato plants produced maximum top yields at soil exchangeable Al <3.0 cmol ((+)/kg, with a 10% yield reduction coinciding with a value of approximately 5.0 cmol (+)/kg. The value was lower for the Bisinella soil than the Garret soil. In the case of pH, maximum yield in both soils was evident at a soil pH of 5.0 with 90% of maximum yield being achieved at about pH 4.7. These results suggest that soil pH would be a good index for Al toxicity. The close relationships between sweet potato growth and both exchangeable Al and soil pH need to be explored further to determine whether it will hold across a wide range of acid soil groups.
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Priyanto, Slamet Bambang, Roy Efendi, and Ahmad Muliadi. "Efektifitas penggunaan beberapa indeks toleransi untuk menyeleksi jagung toleran nitrogen rendah." Jurnal Agro 9, no. 2 (2022): 241–51. http://dx.doi.org/10.15575/20291.
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Keakuratan dalam seleksi jagung hibrida toleran N rendah dapat ditingkatkan dengan penggunaan beberapa indeks seleksi secara sekaligus. Penelitian ini bertujuan mengidentifikasi indeks toleransi yang sesuai untuk seleksi jagung hibrida toleran N rendah serta memilih jagung hibrida toleran N rendah. Penelitian dilaksanakan di IP2TP Bajeng Balai Penelitian Tanaman Serealia Kabupaten Gowa bulan April sampai dengan September 2021. Sebanyak 8 hibrida dan 2 varietas pembanding ditanam pada rancangan tersarang tiga ulangan. Genotipe tersarang pada taraf pupuk N. Taraf pupuk N meliputi 100 kg N ha-1 dan 200 kg N ha-1. Indeks toleransi meliputi Tolerance (TOL), Mean Productivity (MP), Geometric Mean Productivity (GMP), Harmonic Mean (HM), Stress Tolerant Index (STI), Relative Tolerant Index (RTI), Stress Susceptibility Index (SSI), Yield Index (YI), Stress Relative Index (SI), Yield Stability Index (YSI), Stress Susceptibility Percentage Index (SSPI). Hasil penelitian menunjukkan bahwa indeks toleransi menunjukkan bahwa MP, GMP, HM dan STI merupakan yang paling sesuai untuk menyeleksi hibrida toleran N rendah. Hibrida HLN 02 dan HLN 06 merupakan hibrida yang toleran terhadap N rendah, sedangkan Hibrida HLN 03 dan HLN 07 dan ADV 777 termasuk peka. Berdasarkan hasil biji pada pemupukan 100 kg N ha-1 dan 200 kg N ha-1 dan indeks toleransi serta analisis kluster.ABSTRACTLow N tolerant hybrid maize selection accuracy can be increased by using several selection indices simultaneously. This study's objective was to identify the proper tolerance index for low N tolerant hybrid maize selection and to determine the low N tolerant hybrid maize. The research was conducted at IP2TP Bajeng Indonesian Cereal Crop Institute Gowa Regency from April to September 2021. Eight promising hybrid and two check varieties were planted in a nested design with three replications. The genotypes were nested at the N fertilizer level. The N fertilizer levels were 100 kg N ha-1 and 200 kg N ha-1. The tolerance index used was Tolerance (TOL), Mean Productivity (MP), Geometric Mean Productivity (GMP), Harmonic Mean (HM), Stress Tolerant Index (STI), Relative Tolerant Index (RTI), Stress Susceptibility Index (SSI), Yield Index (YI), Stress Relative Index (SI), Yield Stability Index (YSI), Stress Susceptibility Percentage Index (SSPI). The results showed that tolerance index MP, GMP, HM, and STI were the most suitable for electing low N tolerant hybrids maize. hybrids HLN 02 and HLN 06 were low N tolerant; meanwhile, HLN 03 and HLN 07 and ADV 777 were susceptible based on yields at 100 kg N ha-1 and 200 kg N ha-1 fertilization, tolerant indexes, and clustering.
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Cui, S. Y., and D. Y. Yu. "Estimates of relative contribution of biomass, harvest index and yield components to soybean yield improvements in China." Plant Breeding 124, no. 5 (2005): 473–76. http://dx.doi.org/10.1111/j.1439-0523.2005.01112.x.
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Moody, P. W., T. Dickson, and R. L. Aitken. "Field amelioration of acidic soils in south-east Queensland. III. Relationships of maize yield response to lime and unamended soil properties." Australian Journal of Agricultural Research 49, no. 4 (1998): 649. http://dx.doi.org/10.1071/a97047.
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Maize (Zea mays) grain yield responses to rates of lime were measured at 19 sites onseveral soil types in south-east Queensland. At some sites, one rate of gypsum or phosphogypsum was also applied. Relative grain yield (100 mean yield of nil lime treatment/maximum yield) was correlated with each of soil pH (1 : 5 water and 1 : 5 0·01 M CaCl2), soil solution pH, exchangeable (1 M KCl) Al, exchangeable (1 M NH4Cl) Ca, Al saturation of the effective cation exchange capacity (ECEC), Ca saturation of the ECEC, and 0·01 M CaCl2 extractable Mn and Al. Across all soil types, Mitscherlich fits indicated that most of the variation in relative grain yield was accounted for by either Ca saturation (R2 = 0·62) or soil solution pH (R2 = 0·61), although soil pH(water) (R2 =0·53), Al saturation (R2 = 0·46), exchangeable Ca (R2 = 0·42), soil pH(CaCl2) (R2 = 0·40), and CaCl2-extractable Mn (R2 = 0·33) also accounted for significant (P < 0·05) amounts of variation. These results demonstrate that one or both of Al and Mn toxicities were having an impact on yieldat different sites. The contrast between the lack of responses to gypsum/phosphogypsum at mostlime responsive sites and the observation that Ca saturation was well correlated with relative grainyield suggested an ameliorating effect of Ca on Al toxicity. This effect was captured by an index,Al saturation/Ca saturation, which was well correlated with relative grain yield (R2 = 0·66 for a Mitscherlich fit). A step-up regression approach indicated that most variation in relative grain yield (RY) could beaccounted for by the following equation: The assessment of factors likely to limit yield on strongly acidic soils of the region will therefore needto include indices of Al and Mn toxicities as well as Ca status. Soil pH integrated the effects of these factors on yield, and as a single index, was shown to bean effective diagnostic tool. Relative grain yields of 90% were associated with pH values in the soil solution, 1 : 5 water and 1 : 5 0·01 M CaCl2 of 4·5, 5·2, and 4·4, respectively.
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VASIC, N., M. IVANOVIC, L. A. PETERNELLI, D. JOCKOVIC, M. STOJAKOVIC, and J. BOCANSKI. "GENETIC RELATIONSHIPS BETWEEN GRAIN YIELD AND YIELD COMPONENTS IN A SYNTHETIC MAIZE POPULATION AND THEIR IMPLICATIONS IN SELECTION." Acta Agronomica Hungarica 49, no. 4 (2001): 337–42. http://dx.doi.org/10.1556/aagr.49.2001.4.4.
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The synthetic maize population 316PO2 was subjected to genetic correlation analyses between grain yield, yield components and morphological traits. The purpose was to enable estimates to be made of the advantage of using selection indices compared with selection based on grain yield only, and if that advantage was present, to choose enough simple selection indices for practical use. Selection indices were constructed out of four traits highly significantly correlated with grain yield, in addition to yield itself. Grain yield exhibited a highly significant additive genetic correlation with ear diameter (ra=0.588**), kernels row-1 (ra=0.643**), ears plant-1 (ra=0.871**) and ear height (ra=0.427**). The most efficient index was Index No. 14 (R.E.I12345= 108.83%), which included all four traits and grain yield. Index No. 3, one of the simplest forms of index, including only ears plant-1 and grain yield, showed slightly less relative efficiency (R.E.I35=107.24%) than Index No. 14. Using this simple form of index with two characters (Index No. 3) could improve the efficiency of selection for grain yield. The estimated advantage from its use is 179.6 kg/selection cycle for grain yield over selection based only on grain yield.
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Caldas, João Victor dos Santos, Alessandro Guerra da Silva, Guilherme Braga Pereira Braz, et al. "Weed Competition on Soybean Varieties from Different Relative Maturity Groups." Agriculture 13, no. 3 (2023): 725. http://dx.doi.org/10.3390/agriculture13030725.
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One factor limiting the achievement of high yields in the soybean crop is weed interference. The level of weed interference can vary according to the specificities of the weed community but also due to the agronomic characteristics of the soybean varieties. The objective of this work was to evaluate the effects of weed interference on soybean varieties of different relative maturity groups (RMG). A field experiment was implemented in a randomized complete block design, in a 3 × 4 factorial scheme, with five replications. The treatments were composed of the varieties BMX Flecha® (RMG 6.6), BMX Power® (RMG 7.3), and BMX Bônus® (RMG 7.9), associated with the following four weed managements: weeding throughout the cycle; weeded up to 20 days after emergence (DAE); weeded after 20 DAE until the end of soybean cycle; not weeded throughout the entire cycle. There was no interaction between the effects of the varieties and the weed management for emergence speed index, plant height, chlorophyll, first pod height insertion, plant population, thousand-grain weight and yield. The initial weed management caused changes in the composition of the weed community. The managements weeded throughout the cycle and weeded up until 20 DAE provided higher levels of chlorophyll and grain yield. The management without weeding during the entire cycle negatively influenced yield components. Late interventions in weed control, regardless of the soybean variety, result in yield losses.
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B. Harsha Vardhan, Narasimhulu Ragimekula, M. Shanthi Priya, and A. Chandra Sekhar. "Association Analysis for Morpho-Physiological and Yield-Attributing Traits in Foxtail Millet (<i>Setaria italica</i> L. Beauv.)." Annals of Arid Zone 64, no. 1 (2025): 129–34. https://doi.org/10.56093/aaz.v64i1.156413.
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In winter (rabi) 2023–2024, at the Regional Agricultural Research Station, Nandyal, research on trait association and path analysis were carried out with an emphasis on 16 morpho-physiological and yield-attributing traits among 50 foxtail millet germplasm accessions. The results revealed that the majority of genotypic correlation coefficient estimations were higher than corresponding phenotypic correlations indicating the strong inherent associations among the traits. The yield-attributing traits viz., fodder yield plant-1, harvest index, plant height, panicle length, flag leaf length at flowering, 1000 grain weight, days to 50% flowering and flag leaf width at flowering had a significant and positive association with grain yield plant-1, whereas abortive grain rate and number of productive tillers had displayed negative association. Grain yield plant-1 was found to be significant and positively associated with physiological traits such as photosynthetic rate, stomatal conductance, transpiration rate, and relative water content, suggesting strong source and sink relationship. The strong and favorable direct impacts of fodder yield plant-1, harvest index, days to 50% flowering, flag leaf length and width at flowering, photosynthetic rate, relative water content, abortive grain rate and 1000 grain weight on grain yield plant-1 were found in the genotypic and phenotypic path analysis. Based on trait association and path analysis, the most important yield-attributing traits were the fodder yield plant-1, harvest index, flag leaf length and width, photosynthetic rate, relative water content and the 1000-grain weight. Therefore, these attributes should be given top priority when formulating the selection criteria for the foxtail millet grain yield improvement programme
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Dhyani, Kamla, Alok Shukla, and R. S. Verma. "Comparative analysis of changes in leaf area index in different wheat genotypes exposed to high temperature stress by late sown condition." Journal of Applied and Natural Science 9, no. 4 (2017): 2410–13. http://dx.doi.org/10.31018/jans.v9i4.1546.
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High temperature stress during grain-filling period is one of the major environmental constraints limiting the grain yield of wheat in India. Crop growth response and relative performance of yield components of 12 wheat (Triticum aestivum) genotypes were studied in two date of sowing in crop research center (Pantnagar) to identify the causes of yield reduction in wheat particularly Leaf Area Index and its impact in yield loss and other tolerance mech-anism and comparative study of LAI and yield attributes to identify the genotype for high temperature tolerance in late sown condition. The higher temperature enhanced plant growth, flowering, and maturation which ultimately effects the crop performance in case of yield (Leaf Area Index, grain weight/spike and test weight were drastically reduced in time under high temperature. Out of 12 diverse genotypes namely HI 1539, DBW 14, HW 5021, HS 240, PBW-574, Raj 4101, Lok 54, Raj 3765, WH 1021, K-0-307, HW 2045 and HI1544,four were (Lok54, Raj3765, HI1539 and HI1544 ) were characterized as high temperature tolerant based on their relative performance in leaf area index, grain yield and heat susceptibility index. Leaf area Index studies in context to heat stress in wheat is least studied area in heat tolerance research in wheat (Triticum aestivum), in the present study LAI is used as a screening tool for heat tolerance and effect of LAI in wheat yield.
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R, Dhivya, Venkatesan K, Jeyakumar P, and Pugalendhi L. "Seasonal Influence on Physiological Parameters and Yield of Dolichos Bean (Dolichos lablab (Roxb.) (L) var. typicus) Genotypes." Madras Agricultural Journal 100, March (2013): 57–61. http://dx.doi.org/10.29321/maj.10.001238.
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The response of Dolichos bean genotypes to different seasons in relation to physiological parameters and yield was studied during 2009-2010. Leaf area, light interception, specific leaf weight, chlorophyll content, chlorophyll stability index and relative water content differed with genotypes and seasons. With respect to genotypes, Dbp-3 recorded the highest leaf area, total dry matter production, light interception, specific leaf weight, chlorophyll content, chlorophyll stability index and relative water content which in turn reflected on yield. The early sown crop i.e. crop sown at July-August season resulted in good development of physiological characters as well as yield. Among the treatment combinations, the highest value of physiological parameters and yield was recorded in Dbp-3 sown during July-August season.
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Nasir, Mohammad, A. Islam, Md Islam, Sharif Ahmed, Md Salam, and Md Anwar. "Weed competitiveness of popular maize varieties of Bangladesh." Fundamental and Applied Agriculture 9, no. 4 (2024): 294. https://doi.org/10.5455/faa.243245.
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Weed competition is a major constraint to maize production, and the selection of weed-competitive varieties can significantly reduce yield losses necessitating the identification of varieties with superior weed competitiveness. This study evaluated the weed competitiveness of 12 popular maize varieties in Bangladesh under weedy and weed-free conditions during the 2018-2019 rabi season using a split-plot design. Weed competitiveness was assessed based on crop growth, yield, weed density, and weed dry biomass. Results revealed significant variability in weed competitiveness among the tested varieties. BARI Hybrid Bhutta 13 exhibited the highest weed competitiveness, with the lowest relative yield loss (40%) and the highest weed competitive index (6.9). In contrast, Hiramon showed the highest relative yield loss (85%), closely followed by Mohabir and PacD22, while Khoi Bhutta recorded the lowest weed competitive index. Under season-long weedy and weed-free conditions, BARI Hybrid Bhutta 13 achieved the highest grain yield (9.8 t ha⁻¹), whereas BARI Hybrid Bhutta 12 and Mohabir produced the lowest yields in both conditions. These findings highlight substantial varietal differences in weed competitiveness, emphasizing the potential of selecting weed-tolerant maize varieties to mitigate yield losses and improve productivity. This study provides valuable insights for farmers and breeders in identifying and promoting weed-competitive maize varieties, contributing to sustainable maize production in Bangladesh.
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HUCL, P., and R. J. BAKER. "SEEDING RATE EFFECTS ON LOW-TILLERING SPRING WHEATS IN A SEMIARID ENVIRONMENT." Canadian Journal of Plant Science 70, no. 1 (1990): 9–17. http://dx.doi.org/10.4141/cjps90-002.
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To determine if increased seeding rates would alter relative yields of traditional and low-tillering genotypes, a high-tillering (Neepawa), a low-tillering (Siete Cerros), and an oligoculm (M1417) spring wheat (Triticum aestivum L.) genotype were seeded in replicated field trials at two locations in 1984 and 1985. A four-replication split-plot design, with genotypes assigned to main plots and seeding rates (40, 80 160, 320 and 640 seeds m−2) to subplots, was used for each experiment. Grain yield and its components were measured on individual plots or on main stems of five plants in each plot. All three genotypes expressed maximum yield at the same seeding rate (640 seeds m−2 in 1984 and 320 seeds m−2 in 1985) in the semiarid conditions of these experiments. Despite diverse tillering habits, the relative yields of these three genotypes could not be altered by changing seeding rates. On average, Siete Cerros (low-tillering) yielded 15% more than Neepawa and 17% more than M1417. Neepawa had lower grain yields than M1417 at all seeding rates in 1984, but higher grain yields in 1985. A similar change in relative performance of these two genotypes was observed for harvest index of the main stem but not for main stem grain yield kernels spike −1 on the main stem or kernel weight.Key words: Wheat (spring), oligoculm, yield components, genotype-environmental interaction.
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Verma, Ajay, and G. P. Singh. "Simultaneous application of AMMI measures and yield for stability analysis of wheat genotypes evaluated under irrigated late sown conditions of Central Zone of India." Journal of Applied and Natural Science 12, no. 4 (2020): 541–49. http://dx.doi.org/10.31018/jans.v12i4.2391.
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Reports on biased interpretation for the stability of the genotypes under AMMI analysis, considering only the first two interaction principal components, has been observed in recent past. Simultaneous use of yield and stability of genotypes in a single measure had been advocated for identification of highly productive and broadly adapted genotypes. The performance of superiority index, allowed variable weighting mechanism for yield and stability, has been compared with AMMI based measures. For the first year (2018-19) Superiority index, weighting 0.65 and 0.35 for yield and stability, found UAS3002, MP3336 and HI1633 as of stable performance with high yield. Recent analytic measures the relative proportion of genotypic value (PRVG) and Harmonic mean of the relative proportion of genotypic value (MHPRVG) selected CG1029, HI1634 and HD2932 wheat genotypes. Indirect relations were expressed by Superiority Index (SI) with other stability measures. Superiority index saw stable performance along with high yield of HD2864 and HI1634 for the second year 2019-20. PRVG as well as MHPRVG measures observed suitability of CG1029 and HD2864 while MP3336 as unstable wheat genotypes. Values of SI measure had expressed only indirect relations of high degree with stability measures except with yield, PRVG and MHPRVG values. Stability measures by the simultaneous use of AMMI and yield would be more meaning full and useful as compared to measures consider either the AMMI or yield of genotypes only.
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Xiao, Yugu, and Jing Yao. "Double trigger agricultural insurance products with weather index and yield index." China Agricultural Economic Review 11, no. 2 (2019): 299–316. http://dx.doi.org/10.1108/caer-01-2018-0021.
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Purpose Agricultural weather index insurance (WII) has been introduced in pilot or experimental form in many countries. However, the effective demand for WII is often limited by the impact of the basis risk. Thus, the purpose of this paper is to propose a new type of double trigger product, named “supplement” type, to reduce basis risk and improve the performance of the standalone WII. Design/methodology/approach Two measures of performance are introduced by the certainty equivalent income of expected utility theory. Through the Monte Carlo experiments and empirical study, this paper compares the performance of three types of double trigger products. Findings The findings indicate that the supplement type can significantly improve the performance of the single weather index product. First, it covers the downside basis risk and the catastrophic basis risk when the standalone WII fails to do so, especially in case of extreme losses. Second, it is superior when the correlation between the weather index and the yield index is not so strong, and can further enhance the performance of insurance even when the weather index and the yield index are highly correlated, for which the standalone WII could perform well. Originality/value The supplement type double trigger product proposed in this paper as an enhancement version finds a more preferable way to improve the standalone WII with relative lower complexity.
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Parveen, Rabiya, Satish Kumar Singh, Mithilesh Kumar Singh, and Mainak Barman. "Character association studies in Bread wheat genotypes for early heat tolerance and grain micronutrient content." Environment Conservation Journal 22, no. 1&2 (2021): 111–25. http://dx.doi.org/10.36953/ecj.2021.221216.
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Thirty bread wheat genotypes were tested by adopting Randomized Block Design with three replications during 2019-20, under two different environments, i.e. early and timely sown conditions. The ultimate goal was to determine the relationship between yield and yield contributing traits and classify traits that have the highest direct and indirect effects on grain yield under both environmental circumstances. Grain yield was positively and significantly correlated with no. of tiller/plant, no. of grains/spike, relative water content, spike fertility, harvest index, grain zinc content and chlorophyll content at the level of both genotype and phenotype; conversely, found significantly negative with canopy temperature and non-significant with days to 50 % flowering and seedling length. Under stress condition, the correlation for grain yield/plant was found significant, and it was correlated positively with no. of tiller/plant, spike fertility, relative water content, harvest index and grain zinc content and non-significantly with seedling length, no. of grain/spike, chlorophyll content, flag leaf area and thousand-grain weight. At the level of both genotype and phenotype, grain yield per plant had a high direct effect in the positive direction by harvest index followed by no. of tiller/plant, no. of grain/spike, relative water content. Thus, more weightage should be given towards these traits as selecting these traits can be rewarding to achieve high yielding wheat genotypes.
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Azizah, Nur, Ahadiyat Yugi Rahayu, Noor Farid, and Okti Herliana. "Pengaruh Refugia Bunga Telekan (Tagetes erecta) dan Bunga Kertas (Zinnia elegans) pada Populasi Artropoda dan Hasil Tanaman Padi." Jurnal Ilmu Pertanian Indonesia 27, no. 1 (2022): 54–61. http://dx.doi.org/10.18343/jipi.27.1.54.
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This study aimed to determine the effect of refugia (Tagetes erecta and Zinnia elegans) plants on the relative abundance and diversity of Arthropod's dominance in the rice plant area and on rice yield. The Arthropods were observed by the visual control method at each rice growth stage. Observations were made during 15 minutes in five plots of rice area and one refugium block at three different times (08.00‒10.00, 12.00‒14.00, and 15.00‒17.00. The morphological features were identified and recorded to identify the species level and grouped according to their ecological niches. The relative abundance and Shannon Diversity Index were calculated. The rice plants' growth data and yield components were analyzed by ANOVA followed by DMRT if there were any significant differences among the treatments. Relative abundance of dominant arthropods on rice land planted with Zinnia elegans was Solenopsis geminata (11.07%), Leptocorisa oratorius (38.37%), and Hypolimnas bolina (0.17%) with species diversity index values of 3.25%; 2.94%, and 2.56%, respectively. In contrast, the relative abundance of arthropods in rice land planted with Tagetes erecta were Cardiochiles philippinensis (8.84%), Oxya chinensis (25.45%), and Scirpophaga incertulas (0.34%) with moderate diversity index values. The Tagetes erecta gave an equivalent result of rice yield with the control, namely 8,10 t/ha and 7,60 t/ha, respectively, while the Zinnia elegans offers rice yield of 6,30 t/ha.
 
 Keywords: arthropod diversity, paddy yield, Tagetes erecta L, Zinnia elegans
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Khosravirad, M., M. Omid, F. Sarmadian, and S. Hosseinpour. "PREDICTING SUGARCANE YIELDS IN KHUZESTAN USING A LARGE TIME-SERIES OF REMOTE SENSING IMAGERY REGION." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-4/W18 (October 18, 2019): 645–48. http://dx.doi.org/10.5194/isprs-archives-xlii-4-w18-645-2019.
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Abstract. This study aimed to evaluate the power of various vegetation indices for sugarcane yield modelling in Shoeibeyeh area in Khuzestan province of Iran. Seven indices were extracted from satellite images and were then converted to seven days' time-series via interpolation. To eliminate noise from the time-series data, all of them were reconstructed using the Savitzky-Golay algorithm. Thus seven different time-series of vegetation indices were obtained. The growth profile was drawn via averaging of NDVI time-series data and was divided into three growth intervals. Then the accumulative values of vegetation indices related to first and second periods of growth (from 2004 to 2016 extracted from time-series data) were evaluated by simple linear regression models against the average observed yields efficiency. The result showed the accumulative IAVI (γ = 1.4) vegetation index relative to first period of growth with R2 = 0.66 and RMSE = 3.78 ton/ha and the accumulative NDI vegetation index relative to second period of growth with R2 = 0.66 and RMSE = 3.79 ton/ha and the accumulative NDI vegetation index relative to sum of the first and the second growth periods with R2 = 0.78 and RMSE = 3.09 ton/ha had good agreement with sugarcane stem yield efficiency at the middle of growth and before harvesting season.
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Balyan, H. S., and Tejbir Singh. "Character association analysis in common wheat (Triticum aestivum L.)." Genome 29, no. 2 (1987): 392–94. http://dx.doi.org/10.1139/g87-068.
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Grain yield of wheat as a component characteristic of total dry matter (biological) yield is governed by harvest index (V. P. Kulshrestha and H. K. Jain. 1982. Z. Pflanzenzuecht. 89: 19–30). At the phenotypic level, both the grain and biological yields are dependent upon a number of measurable agronomic characteristics such as plant height, tiller number, spike length, and grains per spike, etc. From a breeder's point of view, it is of great value to know the relative significance of these characteristics in determining grain yield to design appropriate selection strategies. The present study evaluated the covariability of yield in relation to various agronomic traits and ascertained their direct and indirect contributions towards grain yield. Key words: wheat, grain yield.
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Mohammadi, Reza, and Abdolvahab Abdulahi. "Evaluation of durum wheat genotypes based on drought tolerance indices under different levels of drought stress." Journal of Agricultural Sciences, Belgrade 62, no. 1 (2017): 1–14. http://dx.doi.org/10.2298/jas1701001m.
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Objectives of this study were to assess durum wheat genotypes for drought tolerance and to study relationships among different drought tolerance indices under different drought stress conditions. The total of twenty-two durum wheat lines was evaluated in a RCBD experiment with three replications for three cropping seasons (2008-2009; 2009-2010 and 2010-2011). Different drought indices such as tolerance (TOL), mean productivity (MP), mean relative performance (MRP), stress susceptibility index (SSI), modified severity stress index (SSSI), geometric mean productivity (GMP), stress tolerance index (STI), yield stability index (YSI), relative efficiency index (REI) and drought response index (DRI) were determined based on yields under drought and non-drought conditions. The studied genotypes showed considerable variation in performance and tolerated various drought conditions that could be exploited in the durum wheat breeding program. The screening of genotypes for drought tolerance in environments with a greater value of stress intensity (SI) will be more efficient in the grouping of indices and genotype selection. The indices were classified into groups (G1 and G2). The group G1, which consisted of the indices REI, STI, MRP, GMP, DRI and YSI, distinguished genotypes with higher yield in different levels of drought stress. The durum breeding line nos. 1, 11, 10, 13, 8, 9, and 12 were superior based on the group G1 and could be regarded for further evaluation in drought-prone environments.
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Tigga, Prabha, R. K. Samaiya, Yogendra Singh, and Jhilick Banerjee. "Effect of Plant Growth Regulators on Physiological Productivity and Seed Quality of Soybean [Glycine Max (L.) Merill]." Biotechnology Journal International 28, no. 4 (2024): 83–98. http://dx.doi.org/10.9734/bji/2024/v28i4730.
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The current study was carried out on soybean variety JS 20-98 seeds that were treated to varying concentrations of plant growth regulators (PGRs). These seeds were used in field studies using Randomised Block Design (RBD) with four replications, and the observations were recorded on phenophasic observations, such as days to 50% flowering, days to pod formation, days to seed formation, days to physiological maturity, and days to field maturity.Determination of dry matter production and its partitioning in various plant parts (leaves, branches, main stem, and pod) at 45 DAS, 60 DAS, 75 DAS, and 90 DAS. Physiological obsdervations (Growth analytical parameters), Leaf Area Index (LAI), Leaf Area Duration (LAD), Crop Growth Rate (CGR), Relative Growth Rate (RGR), Specific Leaf Area (SLA), Specific Leaf Weight (SLW), Biomass Duration (BMD), Chlorophyll Content Index (CCI), Relative Water Content (RWC). Yield and yield components included viz; plant height (cm), number of branches plant-1, number of pods plant-1, number of seeds pod-1, pod length (mm), pod width (mm), pod girth (mm), seed index (g), seed yield (g plant-1and kg ha-1), biological yield (g plant-1 and kg ha-1), harvest index (%). The biochemical estimation includes moisture (%), ash (%), crude fibre (%), total carbohydrate (%), protein (%), and fat (%). However, seed quality traits include germination (%), seedling length (cm), seed vigour index-I, seed vigour index-II, seedling dry weight (g), root length (cm), and shoot length (cm) in soybean. The treatment GA @ 3 ml L-1 (T5) produced the highest seed yield of 2429.93 kg ha-1, biological yield of 6804.47 kg ha-1, and harvest index of 35.71% among the six PGR treatments on soybean. The greatest value for seed quality parameters, especially germination (%), seedling dry weight (g), seedling length (cm), seed vigour index-I, and seed vigour index-II was recorded under the treatment GA @ 3 ml L-1 (T5).
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Ahmed, Ayasha, Jahangir Alam Tarafder, Mohammad Kamal Hoassain, and Nazmul Alam. "Genotypic potentiality and selection index of ridge gourd (Luffa acutangula L.)." Bangladesh Journal of Botany 49, no. 4 (2020): 1169–75. http://dx.doi.org/10.3329/bjb.v49i4.52656.
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Fifteen ridge gourd genotypes were investigated to select the superior genotypes. The overall analysis reveals that PCV was higher than GCV for all the traits. Significant variation was found among genotypes for the qualitative traits under divergence analysis. The selection index reveals that maximum genetic gain and relative efficiency over selection for yield was obtained for the index I123 based on yield/plant (g), No. of secondary branch, No. of male flower/plant characters. In the presented functions, selection index I1234 and I12345 showed highest relative efficiency over direct selection and genetic gain when all the characters were included to construct the selection index. On the basis of performance, the genotype-3023 was found to be most promising parent in order to develop a commercial ridge gourd variety.
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Kirthiga, S. M., and N. R. Patel. "In-Season Wheat Yield Forecasting at High Resolution Using Regional Climate Model and Crop Model." AgriEngineering 4, no. 4 (2022): 1054–75. http://dx.doi.org/10.3390/agriengineering4040066.
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In-season crop production forecasts at the regional or sub-regional scale are essential to aid in food security through early warning of harvest shortfall/surplus, tailoring crop management decisions and addressing climatic shock. Considering the efforts to establish a framework towards quantifying the crop yield prediction at regional scales are limited, we investigated the utility of combining crop model with the regional weather prediction model to forecast winter wheat yields over space. The exercise was performed for various lead-times in the regions of Punjab and Haryana for the years 2008–2009. A numerical weather prediction (NWP) model was used to generate micro-meteorological variables at different lead times (1-week, 2-weeks, 3-weeks and 5-weeks) ahead of crop harvest and used within the CERES-Wheat crop simulation model gridded framework at a spatial resolution of 10 km. Various scenarios of the yield forecasts were verified with district-wide reported yield values. Average deviations of −12 to 3% from the actual district-wise wheat yields were observed across the lead times. The 3-weeks-ahead yield forecasts yielded a maximum agreement index of 0.86 with a root mean squared error (RMSE) of 327.75 kg/ha and a relative deviation of −5.35%. The critical crop growth stages were found to be highly sensitive to the errors in the weather forecast, and thus made a huge impact on the predicted crop yields. The 5-weeks-ahead weather forecasts generated anomalous meteorological data during flowering and grain-filling crop growth stages, and thus had the highest negative impact on the simulated yields. The agreement index of the 5-week-ahead forecasts was 0.41 with an RMSE of 415.15 kg ha−1 and relative deviation of −2.77 ± 5.01. The proposed methodology showed significant forecast skill for extended space and time scale crop yield forecasting, offering scope for further research and practical applicability.
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Gyan Singh and Rahil Akhtar Usmani. "Decomposition of production growth and identification of efficient cropping zones for major pulse crops in Uttar Pradesh and Uttarakhand." Journal of Food Legumes 37, no. 2 (2024): 196–204. http://dx.doi.org/10.59797/jfl.v37.i2.195.
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The study’s goal is to decompose pulse production growth in Uttar Pradesh and Uttarakhand and identify efficient copping zones for both states. The total change in production was decomposed into three effects, i.e., the area effect (ΔA. Y0), the yield effect (ΔY. A0.), and the interaction effect (ΔA. ΔY). The relative spread index (RSI) and relative yield index (RYI) were computed to identify the potential cropping districts for different pulses grown in Uttar Pradesh and Uttarakhand. We classified districts into four zones: most efficient, efficient, not efficient, and highly inefficient. A higher RYI corresponds to higher yield districts, and a higher RSI indicates a more cultivated area. Districts with a high relative spread index and a low relative yield index indicate that a particular pulse is not suitable for that district. We suggest addressing production issues through research, marketing, and extension services to enhance the productivity level of pulse crops. The results from Uttar Pradesh are highly encouraging, indicating that the yield effect has primarily contributed to the growth in pulse production. The government’s policies, schemes, and initiatives to promote pulse production and decrease imports are moving in the right direction. According to the methodological analysis, 57 districts are among the most efficient cropping zones for all selected pulse crops in Uttar Pradesh. In the case of Uttarakhand, for all selected pulses, 20 percent of districts come under the most efficient cropping zone, and 20 percent of districts come under the most efficient cropping zone. The highest 40 percent of districts fell under highly inefficient cropping zones. Lack of high-quality inputs, technology adoption, and poor market and extension services may be the reasons for low productivity in these districts. An increase in productivity with low costs could help the country reduce imports of pulses and check the flow of foreign currency.
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Missanjo, Edward, Venancio Imbayarwo-Chikosi, and Tinyiko Halimani. "A Proposed Selection Index for Jersey Cattle in Zimbabwe." ISRN Veterinary Science 2013 (March 27, 2013): 1–3. http://dx.doi.org/10.1155/2013/148030.
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A multitrait selection index for Zimbabwean Jersey cattle was constructed. The breeding objective was defined in terms of production and functionality traits. The production component of the index included milk yield , butterfat yield , protein yield , butterfat percent , and protein percent , while the functional component included the somatic cell count (SCC). The index was termed as . The accuracy of the index was 91.1%, and the correlation between this index and the aggregate breeding objective was 0.954. A selection index is more important in the selection of sires and cows. This leads to the greatest genetic progress and hence productivity in the dairy sector. Therefore, the application of the selection index developed is necessary if the dairy cattle industry is to maximise the exploitation of genetics and to improve its relative competitive position.
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Blum, A., J. Mayer, and G. Golan. "Agronomic and physiological assessments of genotypic variation for drought resistance in sorghum." Australian Journal of Agricultural Research 40, no. 1 (1989): 49. http://dx.doi.org/10.1071/ar9890049.
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This study was designed to assess genotypic variability for drought resistance in sorghum (Sorghum bicolor [L.] Moench) and to conclude on the possible physiological differences between drought resistant and drought susceptible genotypes.Grain yield under drought stress ranged from 184 to 943 g m-2 and relative yield ranged from 35.8 to 103.5% among genotypes. Yield (but not relative yield) under stress was decreased (r= -0.89**) with a longer growth duration of gentoypes. Both stover yield and total biomass under stress increased (r = 0.69** and r = 0.72**, respectively), while harvest index decreased (r = 0.80**) with longer growth duration. Genotypes differed significantly in leaf water potential (LWP), canopy temperature, leaf rolling, leaf carbon exchange rate (CER), stomatal conductance and osmotic adjustment. These data were averaged for the four best ('drought resistant'-R) and the two poorest ('drought susceptible'-S) genotypes in terms of their absolute and relative yields under stress. Compared with S, the R genotypes were earlier in heading and had higher LWP, lower canopy temperature and higher stomatal conductance. While leaf rolling was similar in R and S genotypes, it was found to increase as LWP decreased across all genotypes. Under these stress conditions variations in CER among genotypes on given dates appeared to be affected more by phenology than by plant water status.
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King, Bradley, Christopher Rogers, David Tarkalson, and David Bjorneberg. "Malt Barley Yield and Quality Response to Crop Water Stress Index." Agronomy 14, no. 12 (2024): 2897. https://doi.org/10.3390/agronomy14122897.
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Malt barley is a crucial irrigated crop in the semi-arid Western United States, where the states of Idaho, Colorado, Wyoming, and Utah account for 92% of the irrigated production acreage and 30% of total U.S. production. In this region, spring malt barley’s seasonal evapotranspiration ranges from 400 to 650 mm, and competition for limited water supplies, coupled with drought, is straining regional water resources. This study aimed to investigate the use of canopy temperature for deficit irrigation scheduling of malt barley. Specifically, the objectives were to use data-driven models to estimate well-watered (TLL) and non-transpiring (TUL) canopy temperatures, correlate the crop water stress index (CWSI) with malt barley yield and quality measures, and assess the applicability of CWSI for malt barley irrigation scheduling in a semi-arid climate. A 3-year field study was conducted with five irrigation treatments relative to estimated crop evapotranspiration (full, 75%, 50%, 25%, and no irrigation) and four replicates each. Continuous canopy temperature measurements and meteorological data were collected, and a feedforward neural network model was used to predict TLL, while a physical model was used to estimate TUL. The neural network model accurately predicted TLL, with a strong correlation (R2 = 0.99), a root mean square error of 0.89 °C, and a mean absolute error of 0.70 °C. Significant differences in calculated season-average CWSI were observed between the irrigation treatments, and relative evapotranspiration, malt barley relative yield, test weight, and plump kernels were negatively correlated with the season-average CWSI, while seed protein was positively correlated. The relationship between daily CWSI and fraction of available soil water was well described by an exponential decay function (R2 = 0.72). These results demonstrate the applicability of data-driven models for computing CWSI of irrigated spring malt barley in a semi-arid environment and their ability to assess plant water stress and predict crop yield and quality response from CWSI.
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Frančáková, H., M. Líšková, T. Bojňanská, and J. Mareček. "Germination index as an indicator of malting potential." Czech Journal of Food Sciences 30, No. 4 (2012): 377–84. http://dx.doi.org/10.17221/314/2010-cjfs.
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The malting industry requires malt with a high extract yield, high levels of enzyme activity, and good modification to manufacture beer of excellent quality. The basic raw material for the beer production is the malting barley whose quality is of primary significance. Therefore, barley must be able to germinate vigorously and be post-harvest mature to meet these requirements. We find out to what extent barley physiological parameters influence the changes of malt technological parameters during post-harvest storage. The malt technological parameters investigated were the extract, relative extract at 45&deg;C, Kolbach index, apparent final attenuation, friability, and wort &beta;-glucan in relation to the germination energy and germination index. On the basis of the results obtained, it was found out that the germination index is the most suitable physiological parameter in view of the correlations with malt technological parameters, mainly the extract (r = 0.57) and relative extract at 45&deg;C (r = 0.77). The germination index could be therefore used in the malting industry as a suitable indicator of the malting potential. &nbsp;
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Al-Najjar, Safwan, and Kh Al-Zubaidy. "Evaluation of Relative Efficiency of Several Selection Indices for Prediction of Expected Genetic Advance in Bread Wheat Grain Yield (Triticum aestivum L)." Tikrit Journal for Agricultural Sciences 19, no. 4 (2023): 41–49. http://dx.doi.org/10.25130/tjas.19.4.7.
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This experiment was conducted with fifteen genotypes of bread wheat introduced from ICARDA and two local varieties (Sham6 and Abu-Graib3), using three rows spacing (15, 25 and 35 cm). All genotypes were grown in 7 December, 2017 at Field Crops farm (inside Mosul University) under rain fed conditions with complementary irrigation, using split plots in randomized complete block design with three replications, for evaluation through constructing several selection indices and calculation of the expected gains of grain yield. The analysis of variance results for studied traits (grain yield, plant height, number spikes, biological yield, number of grains per spike, 1000-grain weight and harvest index) showed that mean square of genotypes were highly significant for plant height, number of grains per spike and 1000 grain weight. The selection index constructed from number of grains per spike and harvest index had high increase in the efficiency as compared with direct selection for yield. This indicate of the importance of a selection index based on combination of characters. This index in the present study considered the superior due to its highest efficiency. Using this index for genotypes evaluation revealed that the higher mean of selection index was 109.961 for genotype REYNA-12 with significant difference over Abu-Graib3 and is not with others, followed in importance by Sham6, ATTILA-7, PASTOR-2/BOCRO-2 and HUBARA-5/3/SHA3/SERI//SHA4LLIRA. The local varieties of bread wheat included in this study, (Sham6 and Abu-Graib3) locates at the sequences 2 and 17 respectively.
 
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Juhos, Katalin, Szilárd Szabó, and Márta Ladányi. "Influence of soil properties on crop yield: a multivariate statistical approach." International Agrophysics 29, no. 4 (2015): 433–40. http://dx.doi.org/10.1515/intag-2015-0049.
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Abstract The aim of the study was to reveal the relationship between soil properties and grain yields in an East Hungarian region in regard to weather conditions. Soil pH, EC, carbonate content, soluble and exchangeable Na+, texture, organic carbon, and nutrient contents were analyzed. Yield data (maize, winter wheat, sunflower) from 10 years were standardized using calculated relative yield and yield variability. Weather conditions were characterized by the Pálfai Drought Index. Hydrological and topographical conditions were characterized by the mean altitude of plots. The ranged pedological variables were analyzed using principal component analysis with Varimax rotation. The principal component analysis showed that three principal components with eigenvalues greater than one explained more than 84% of the variability of soil properties. The multiple stepwise principal regression analysis showed that the mean relative yield was linearly correlated with all the three principal component factors (R2 = 0.49, p < 0.01). In droughty years, the sodification, salinization, soil texture, and nutrient contents determined the yields (R2 = 0.30, p < 0.05). In humid years, the lower topographical position, soil organic matter, and nutrient contents were the main limiting factors (R2 = 0.40, p < 0.01). Consequently, the variables can effectively explain the yield variability together with other variables as linear combinations.
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SENER, O., M. ARSLAN, Y. SOYSAL, and M. ERAYMAN. "Estimates of relative yield potential and genetic improvement of wheat cultivars in the Mediterranean region." Journal of Agricultural Science 147, no. 3 (2009): 323–32. http://dx.doi.org/10.1017/s0021859609008454.
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SUMMARYInformation about changes associated with advances in crop productivity is essential for understanding yield-limiting factors and developing new strategies for future breeding programmes. National bread wheat (Triticum aestivum L.) yields in Turkey have risen by an average of 20·8 kg/ha/year from 1925 to 2006. Annual gain in yield attributable to agronomic and genetic improvement averaged c. 11·6 kg/ha/year prior to 1975, but is now averaging c. 15·1 kg/ha/year. In the Mediterranean region, however, the wheat yield trend line (10·9 kg/ha/year) is c. 0·38 lower than that of Turkey. In order to understand whether such a trend was due to the cultivars released over the years, 16 bread wheat cultivars, commonly grown in the region and representing 23 years of breeding, introduction and selection (from 1976 to 1999), were grown in a randomized complete block design with three replicates across 2 years. Data were collected on maturation time, plant height, spike length, spikelet number/spike, grain number/spike, grain weight/spike, 1000 seed weight, harvest index and grain yield. None of the measured plant traits showed any historical cultivar patterns; therefore, the increase in grain yield could not be attributed to a single yield component. Several physiological traits changed during two decades of cultivar releases in the Mediterranean region that led to a genetic gain in grain yield of about 0·5% per year. Years of data and the present field study in the Mediterranean region suggested that the genetic improvement in wheat seemed inadequate and should be reinforced with modern agricultural management practices as well as technological innovations.
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Mrode, R., and G. J. T. Swanson. "A comparison of the efficiency of the repeatability model on observed or transformed yields to a multi-variate analysis." Proceedings of the British Society of Animal Science 1995 (March 1995): 129. http://dx.doi.org/10.1017/s1752756200591248.
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A multi-variate animal model Best Linear Unbiased Prediction (BLUP) on milk, fat and protein yields in different lactations, as different traits, is the optimum method for genetic evaluation in dairy cattle for production. However, this is computationally demanding and usually a repeatability model is performed separately for milk, fat and protein yields. A simulation study by Visscher (1991) showed that the repeatability model on canonical transformed yield rather than on observed yield was a better approximation to a multi-variate analysis using selection index. The aim of this study is to verify, using an animal model, the efficiency of the repeatability model relative to a multi-variate analysis on observed or transformed yields.