Download or read book Seasonal Effects on Physiological Traits Associated with Grain Yield of Soybean Glycine Max L Merrill and Validation of Soygro V 5 42 Model written by Nagesh Kesari and published by . This book was released on 1994 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Understanding Options for Agricultural Production written by G.Y. Tsuji and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 405 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first premise of this book is that farmers need access to options for improving their situation. In agricultural terms, these options might be manage ment alternatives or different crops to grow, that can stabilize or increase household income, that reduce soil degradation and dependence on off-farm inputs, or that exploit local market opportunities. Farmers need a facilitating environment, in which affordable credit is available if needed, in which policies are conducive to judicious management of natural resources, and in which costs and prices of production are stable. Another key ingredient of this facilitating environment is information: an understanding of which options are viable, how these operate at the farm level, and what their impact may be on the things that farmers perceive as being important. The second premise is that systems analysis and simulation have an impor tant role to play in fostering this understanding of options, traditional field experimentation being time-consuming and costly. This book summarizes the activities of the International Benchmark Sites Network for Agrotechnology Transfer (IBSNAT) project, an international initiative funded by the United States Agency for International Development (USAID). IBSNAT was an attempt to demonstrate the effectiveness of understanding options through systems analysis and simulation for the ultimate benefit of farm households in the tropics and subtropics. The idea for the book was first suggested at one of the last IBSNAT group meetings held at the University of Hawaii in 1993.
Download or read book Genetics of Physiological Traits Associated with Drought Tolerance in Soybean glycine Max written by Sumandeep Kaur Bazzer and published by . This book was released on 2020 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soybean (Glycine max L.) is one of the major row crops in the United States, and its production is often limited by drought stress. Physiological traits from exotic germplasm that confer drought tolerance may be useful in improving commercial soybean production. For example, carbon isotope ratio (?13C) is positively correlated with water use efficiency (WUE), and nitrogen isotope ratio (?15N) is negatively correlated with N2 fixation; canopy temperature (CT) is an indicator for genetic variation in transpiration and stomatal conductance. Therefore, the objectives of this research were to identify the genomic regions associated with: (1) ?13C and ?15N using a population of 196 F6-derived recombinant inbred lines (RIL) from PI 416997 × PI 567201D that was phenotyped in four environments, (2) CT and ?13C using a population of 168 F5-derived RILs from KS4895 × Jackson that was phenotyped in multiple environments and irrigation treatments. In the PI 416997 × PI 567201D population, ?13C and ?15N had a wide phenotypic range in all environments, and PI 416997 had higher ?13C and lower ?15N values than PI 567201D. ?13C had high heritability (90%) whereas the heritability of ?15N was relatively lower (35%), indicating that ?15N was more affected by the environment. QTL mapping identified eight loci on seven chromosomes associated with ?13C, and these loci explained between 2.5 to 30% of the phenotypic variation. There were 13 loci on 10 chromosomes associated with ?15N, explaining 1.7 to 14.4% of the phenotypic variation. There were strong interactions between QTLs and environments for ?15N. In the KS4895 × Jackson RIL population, Jackson had a cooler canopy than KS4895, and the heritability of CT had low heritability (31%) across environments. There were 11 loci present on eight chromosomes associated with CT that individually explained 4.6 to 12.3% of the phenotypic variation. The heritability of ?13C in KS4895 × Jackson RIL population heritability was 83% when estimated over environments and over irrigation treatments. A total of 24 QTLs associated with ?13C were identified and clustered in nine genomic loci on seven chromosomes. The identified QTLs for ?13C, ?15N, and CT were co-localized with genomic regions associated with drought tolerance-related traits from previous studies. These genomic regions may be important resources in soybean breeding programs to improve tolerance to drought. Further research is needed to fine map the identified QTLs and validate markers linked with these regions.
Download or read book Effects of Nitrogen Dioxide on Biochemical and Physiological Characteristics of Soybean Glycine Max L Merrill written by Sashikala Sabaratnam and published by . This book was released on 1987 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of the Physiological Quality of Seed of Field Performance of Soybeans Glycine Max L Merrill as Affected by Population Density written by Flávio Popinigis and published by . This book was released on 1973 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Row Width and Plant Density of Seasonal Growth of the Soybean Glycine Max L Merrill written by Joel Eudono Hudgins and published by . This book was released on 1977 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Water Stress Effects on Physiological Processes and Yield of Soybeans written by Mahmoud Fadl El Mula Ahmed and published by . This book was released on 1983 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soybeans [Glycine max (L.) Merr.] cv. Bragg were grown in field lysimeters for the study of water stress effects on certain physiological characteristics during different growth periods. A second objective was to study changes in plant water relations of well-irrigated soybeans during the growing season. Mid-day measurements were taken for soil water potential, leaf water potential components, stomatal diffusive resistence, transpiration, and leaf temperature. In well-irrigated plants, leaf osmotic potential began to decline with the onset of flowering, causing a considerable decrease in the leaf water potential. Mid-day turgor potential maintained hight values (5 to 8 bars) throughout the growing season. Diffusive resistence, transpiration rates, and leaf-to-air temperature differential (leaf temperature minus air temperature) were also constant util after R[indice]5, when diffusive resistance began to increase, transpiration rates decreased and temperature differential increased. This was related to plant aging as the crop approached the late reproductive growth stages. As estomatal diffusive resistance increased, transpiration cooling was less resulting in increased temperature differentials. During the drying cycles, leaf water potential componentes of the stressed plants were, in most cases, lower than teh control plants. Transpiration rates and stomatal conductance were also lower in the stressed plants while leaf-to-air temperature differential was greater. A high correlation was observed between osmotic potential and leaf water potential during drying cycles and was most likely associated with dehydration effect which resulted in increased concentrations of the osmotic components. However, osmotic potential at full turgor (leaf water potential equal to zero), showed progressive decreases during the season, giving values of -9.4, -10.9, -11.6 and -15.1 bars at V[indice]5, R[indice]1, R[indice]5 and R[indice]6 stages, respectively. This reflects changes in osmotic potential of soybeans as they grow from vegetative to reproductive phases. The slope of [phi][indice][pi] versus [phi][indice]L also declined from 0.437 at V[indice]5 to 0.233 at R[indice]6, suggesting reduced plasticity during late reproductive stages. Moisture strees during R[indice]6 resulted in significant diferences in harvest index, 100-seed weigth, percent empty pods, and shelling percentage as compared to the well-watered control. No significant differences in seed yield were observed; however, the data suggests yield reductions of 12%, 13% and 14% due to water withholding during V[indice]5, V[indice]5 plus R[indice]5, and R[indice]6 growth periods, respectively.
Download or read book Genetic Variation for Physiological Traits Affecting Drought Tolerance Among Ontario adapted Commercial Soybean Glycine Max L Merr Varieties Grown in 1 m Rooting Columns written by Michael Gebretsadik Gebre and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Drought stress significantly limits soybean production in Ontario. Identification of physiological traits to improve drought tolerance in soybean would benefit from controlled-environment phenotyping methods. It was hypothesized that elite Ontario-adapted soybean varieties would differ for drought tolerance. A greenhouse culture system was developed employing 1-m rooting columns filled with amended field soil, that presents field-like volumetric soil water content and rooting profiles by depth. Different levels of drought stress were simulated in this system by restoring soil water to 100% (control), 75% (mild stress) or 50% (drought stress) of the maximum soil water holding capacity by daily weighing and watering from first flower (R1) until maturity. The effect of applying fertilizer throughout the 1-m soil profile instead of confining it to the upper 30 cm was tested. Distributing fertilizer over the entire 1-m rooting depth resulted in deeper rooting and more soil water extraction at depth at the R1 stage; however, these effects did not persist until maturity and so did not affect drought tolerance. Fifteen Ontario-adapted commercial soybean varieties were compared for their drought tolerance, defined as the ratio of their seed yield under drought conditions compared to control conditions (seed yield ratio; SYR). Similar to the effects of drought in the field, pod number was by far the yield component most affected, with effects on seeds per pod and single-seed weight being relatively minor. Based on their SYR, two drought-sensitive varieties (Saska and OAC Drayton) and three drought-tolerant varieties (OAC Lakeview, OAC Champion, and PRO 2715R) were identified. Principal components analysis showed that drought-tolerant varieties were those that maintained relatively high water use, shoot dry matter, and pod number under stress. Varieties differed for root biomass distribution by depth, but not for soil water extraction profiles, and there was no evidence that differences in drought tolerance were associated with rooting traits among these fifteen varieties. This study helps define the physiological basis of soybean variety differences in drought tolerance, and provides novel phenotyping tools for soybean breeders to select for root function and yield formation traits that could improve soybean yield under drought stress.
Download or read book Influence of Lodging on Yield and Other Agronomic Characteristics of Soybean Glycine Max L Merrill written by Kian Chai Tan and published by . This book was released on 1977 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Weathering on Soybean Glycine Max L Merrill Seed Quality written by Robert Adalia Burdett (Jr) and published by . This book was released on 1977 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Planting Dates on Growth Yield and Quality of Soybean Glycine Max L Merrill Varieties Viz Clark 63 and Bragg written by Nangare B S. and published by . This book was released on 1973 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Study of Plant and Soil Factors Affecting Seasonal Nitrogen Fixation Yield Formation and Seed Composition in Soybeans written by Luiz Moro Rosso and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soybean [Glycine max (L.) Merr.] production currently faces several challenges linked to global food security (both quantity and quality) raised by an overgrowing human population, limited cropland, and diversified dietary in developed regions. To sustain seed yield and high protein levels, soybeans depend on large nitrogen (N) uptake, which is mostly attained by the symbiotic N fixation (SNF) process. Although SNF has been extensively investigated with single assessments during the season, just a few recent reports looked at the temporality of N sources (soil and SNF) while taking into consideration seasonal dry matter accumulation and soil nitrate (NO3) and ammonium (NH4) availability. Furthermore, it is still unclear how the overall changes in N uptake dynamics supports yield formation and seed components among canopy portions, especially considering the branches as potential contributors for high yield in modern genotypes. Following this rationale, this project presents two overall objectives: 1) to identify the impact of soil NO3 and NH4 temporal availability on seasonal SNF [N derived from the atmosphere (Ndfa)], N uptake, and dry matter accumulation (herein called study 1); and 2) to characterize seed yield, protein, oil, amino acids (AA), and fatty acids (FA) from the main stem and branches (herein called study 2) for different commercial soybean varieties. To address the first objective, four genotypes were field grown at Manhattan (Kansas, US) during 2019 and 2020 growing seasons. Dry matter, N concentration, N uptake, Ndfa, fixed N, soil NO3, and NH4 (60-cm depth) were measured at six phenological stages, along with seed yield, protein, and oil concentration at harvest time. Seasonal exposure to NH4 (area under the curve) showed a stronger suppression of Ndfa at the end of the season than NO3. However, a mid-season NO3 peak delayed uptake from soil and SNF, but only decreased maximum uptake rates from SNF. Additionally, dry matter was used as a seasonal linear predictor of fixed N to simplify the process model. However, this relationship was deeply affected by soil N availability across environments (boundary functions) and also by a potential dry matter threshold around 5 Mg ha−1 across genotypes and site-years. For the second objective, another four genotypes were field-grown during the 2018 and 2019 growing seasons at Ashland Bottoms and Rossville (Kansas, US), respectively. At harvest time, seeds from the upper, middle, lower main stem, and branch nodes were manually separated and assessed for yield, seed size, protein, and oil (seed content and concentration), abundance of limiting AA within protein, and FA ratio (oleic / linoleic + linolenic). The accumulation of protein was more responsive to node position than oil, determining high protein concentration in the upper main stem and high oil concentration in the lower main stem nodes. However, the protein quality (limiting AA) was higher in the lower main stem, while the FA ratio (oil quality) was greater in the upper section of the plant. Branches presented the less-rich seed composition relative to the main stem, but their contribution to yield was positively associated with oil and limiting AA abundance across genotypes. In summary, the main outcomes of the present thesis are related to 1) the importance of soil NO3 and NH4 to regulate Ndfa during the season, 2) the timing of Ndfa assessment or prediction for an accurate fixed N calculation throughout the season, and 3) the underlaying effect of branch yield allocation on the seed composition of the whole soybean plant, plausibly moderating changes across genotypes, environments, and management practices. A better understanding of soybean N acquisition and allocation for yield and quality formation within the plant is important to sustain the yield increase, offset protein decay, and assure cropping systems sustainability and food security in a long-term standpoint.
Download or read book Modelling Crop weed Interactions written by Martin J. Kropff and published by Int. Rice Res. Inst.. This book was released on 1993 with total page 277 pages. Available in PDF, EPUB and Kindle. Book excerpt: General introduction; Empirical models for crop-weed competition; Eco-physiological models for crop-weed competition; Mechanisms of competition for light; Mechanisms of competition for water; Mechanisms of competition for nitrogen; Eco-physiological characterization of the species; Understanding crop-weed interaction in field situation; The impact of environmental and genetic factors; Practical applications.
Download or read book Advances in Crop Modelling for a Sustainable Agriculture written by Kenneth Boote and published by Burleigh Dodds Series in Agric. This book was released on 2019-10-22 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt: Crop modelling has huge potential to improve decision making in farming. This collection reviews advances in next-generation models focused on user needs at the whole farm system and landscape scale.
Download or read book Response of Crops to Limited Water written by Lajpat Ahuja and published by ASA-CSSA-SSSA. This book was released on 2008 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: Water stress and heat stress are considered to be two primary factors that limit crop production in many parts of the world. Global warming appears to be increasing the water requirements of plants. Understanding the impact of water deficit on plant physiological processes and efficient water management are of great concern in maintaining food production to meet ever increasing world food demand. The book addresses various climatic soil and plant factors that contribute to the water use efficiency in plants subjected to water stress. It covers all issues related to soil, plant and climatic factors that contribute to the crop responses to water stress. The books advances the knowledge in improving and sustaining crop yields in ever increasing unpredictable climatic fluctuations This book uses crop simulation models for response of crops to limited water under various management and climatic conditions.
Download or read book Systems approaches for agricultural development written by F.W.T Penning de Vries and published by Springer Science & Business Media. This book was released on 1993 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the International Symposium on Systems Approaches for Agricultural Development, 2-6 December 1991, Bangkok, Thailand
