Soybean Yield Components Research Articles

Soybean yield and yield component distribution across the main axis in response to light enrichment and shading under different densities

A 2-year field experiment was conducted under light enrichment and shading conditions to examine the responses of seed yield and yield components distribution across main axis in soybean. The results showed that the maximum increase in seed yield per plant by light enrichment occurred at 27 plants/m<sup>2</sup>, while the most significant reduction in seed yield per plant by shading occurred at 54 plants/m<sup>2</sup>. Light enrichment beginning at early flowering stage decreased seed size on average by 7% while shading increased seed size on average by 9% over densities and cultivars, resulting in a fewer extent compensation in seed yield decrement. Responses to light enrichment and shading occurred proportionately across the main axis node positions despite the differences in the time (15–20 days) of development of yield components between the high and low node positions. Variation intensity of seed size of three soybeans was dissimilar as a result of changes in the environment during the reproductive period. The small-seed cultivar had the greatest stability in single seed size across the main axis, followed by moderate-seed cultivar, while large-seed cultivar was the least stable. Although maximum seed size may be determined by genetic potential in soybean plants, our results suggested that seed size can still be modified by environmental conditions, and the impact can be expressed through some internal control moderating the final size of most seeds in main stem and in all pods. It indicates that, through redistributing the available resources across main stem to components, soybean plants showed the mechanism, in an attempt to maintain or improve yield in a constantly changing environment.

Effect of moisture stress and low phosphorus on yield of some soybean genotypes

Soybean genotypes belonging to different maturity periods were planted under normal, nutrient (P) and moisture stress conditions in a combined design with three replications. The objective was to determine theeffect of phosphorus and moisture stress on yield and yield components of soybean in order to select varieties that may be suitable for the northern guinea savannah zone of Nigeria. Soybean varieties differed in theirresponse to nutrient and moisture stress. However there was more effect of moisture stress on yield and yield components than for Phosphorus stress. The effect of stress was more pronounced on number of pods per plants. Yield reduction of 88.95% was observed due to effect of moisture stress. Early maturing varieties had least percent yield reduction probably due to escape mechanism.Keywords: Moisture stress, Phosphorus Soybean genotypes

Competition of soybean with blackjack (<i>Bidens pilosa L.</i>)and pigweed(<i>Amaranthus hybridus L.</i>)

Field studies were conducted to evaluate competitiveness between blackjack or pigweed and soybean using replacement series. Plant height of the three species was not affected by interspecific competition. Branching was reduced in soybean at 75 days after plant emergence (DPE), but increased in the weed species. Soybean, blackjack and pigweed shoot dry weight was reduced in most mixtures. The weed species had higher relative growth rate (RGR) and leaf area index (LAI) than soybean. The highest LAI occurred in monoculture pigweed. Competitive ration (CR) values showed that pigweed was the most competitive of the three species. Soybean pod number per plant, 1000 seed weight and grain yield per plant were significantly less in mixtures with the two weed species. Pigweed caused more reduction in soybean yield components than blackjacks. The number of blackjack seeds per head, seed heads per branch and seeds per plant were significantly reduced in mixtures while seed production by pigweed in mixture increased by 30 to 253%. It is concluded that both weed species reduce soybean vegetative growth except for height and components of yield.

Analysis of Soybean Yield Components as Affected by Plant Growth Regulators Applied at Flowering Stages

Analysis of Soybean Yield Components as Affected by Plant Growth Regulators Applied at Flowering Stages

Effect of different tillage systems on the yield and yield components of soybean [ Glycine max (L.) Merr.

Eight different tillage systems were compared in soybean production on one experimental field (chernozem) located in the Baranya region of Croatia over a 4-year period (2001/2002, 2002/2003, 2003/2004, 2004/2005). The dry conditions experienced in 2003 exacerbated the effects of NT and CWNS on the soybean yield. The most stable grain yield was obtained using CSNW and CSDW in all four experimental years. DH, CH and CWDS did not result in any significant reduction in crop yield compared to CT. There was no clear trend regarding the applied tillage systems and grain yield components. The greatest effects on soybean yield and yield components were due to climatic conditions. Different tillage systems had a significant effect on the soybean grain yield and yield components in the four experimental years. The largest differences in stem height were determined between CSNW and NT. The number of pods per plant, the hectolitre mass and the grain yield were significantly lower under NT than under the other tillage systems. The number of fertile nodes of soybean and the number of branches per plant in the experimental years had approximately the same values for all the tillage systems. To sum up, the results achieved with DH, CH, CSDW, CWDS and CSNW were on par with each other and slightly better than CT, and these systems could represent adequate replacements for conventional tillage. No tillage could not be considered as the most favourable for soybean growing.

Responses of soybean yield and yield components to light enrichment and planting density

Light intensity intercepted by the soybean canopy during the reproductive period is an important environmental factor determining soybean yield components and grain yield. A 2-year field experiment was conducted to investigate the effects of light enrichment and its interaction with planting density on yield formation of soybean cultivars. Light enrichment increased seed yield per plant and yield per unit area dramatically ranging from 26-94% (P<0.05) regardless of density and cultivars at lower and moderate density however the yield increase effect was not observed in H339 and HN35 at the high density in 2007. Seed yield and pod number per plant declined with the increased density in 2007 for all cultivars but remained unchanged in 2008 for KN18. There was significant light enrichment-by-density (P<0.05) on yield per plant and pod number per plant, but not on seed number per pod and seed size across the two years. Yield sensitivity to light enrichment differed among soybean cultivars. Adjustments to light enrichment imposed at the early flowering R1 stage increased pod number. Pod number per plant increased 20-119% over the two-years. Seed size in this study was unchanged or reduced slightly by light enrichment. Our data suggest that clarification of mechanisms induced the greatest yields in high population as demonstrated under light enriched conditions may provide insights for crop management and phenotypic improvement.

Effect of Drought Stress and Methanol on Yield and Yield Components of Soybean Max (L 17)

Problem statement: In order to evaluate drought stress and methanol on yield and yield components of soybean in field experiments with factorial experiment inform of a randomized complete block design with three replication in field faculty of agricultural of Islamic Azad University Karaj, at 2008. First factor were sprayed aqueous solutions 0 (control), 7, 14.21, 28 and 35% (v/v) methanol by 3 times during growth season of soybean with 12 days intervals on shoot of soybean. Second factor were drought stress condition in two levels 40 and 70% base of depletion available soil moisture. Approach: This study measured grain yield, biomass HI, 1000 grain weigh, high plants, number of branch, diameter of stem, number of pod on plant, number of hollow pod. Results: Results of the experiment indicated that significant differences exist (p>0.05) between sprayed of solution methanol on parameters. Results also showed that was significant (p>0.05) differences between effect of drought stress levels on measured parameters. Effect of aqueous solution 14, 21 and 28% (v/v) methanol on measured parameters was greater than other treatments. Foliar application of 14 and 21% (v/v) methanol increased leaf area index, crop growth rate, pod growth rate, leaf area duration, pod yield, seed yield, weight of 1000 kernel, mature pods per plants. Conclusion: The lowest grain yield obtained in control and 35% (v/v) methanol treatments. Interaction effects were not significant.

Effect of Fungicide on Soybean Growth and Yield

In response to rising input costs and narrowing profit margins, soybean [Glycine max (L.) Merr.] producers are continually looking for ways to increase soybean yield. One approach being promoted is the use of foliar fungicides, for both foliar pathogen control and nonfungicidal plant physiological effects. The objective of this field experiment was to evaluate a strobilurin and a triazole alone or in combination on soybean in the absence of foliar diseases to determine the potential effect on soybean growth and yield. The experiment was conducted in Iowa at one location in 2005 and two locations in 2006 with four soybean cultivars. Triazole (tebuconazole), a curative fungicide and strobilurin (pyraclostrobin), a preventative fungicide, were applied alone and in combination at growth stages R1, R3, and R5. Low levels of foliar diseases were observed. Seed yield for the control treatment averaged 4308 kg ha−1 across all sites. Foliar fungicides did not affect soybean seed yield. Few differences were observed among the treatments in soybean growth and yield components. Total biomass was 10% greater with the pyraclostrobin applied at R3 compared with the control, and was a result of increased stem weight. In this study, fungicides applied in the absence of foliar disease did not produce nonfungicidal physiological effect or associated yield improvement. It was concluded that environmental conditions and assessment of disease levels should be used as a guide for foliar fungicide application on soybean.

Root and shoot growth, seed composition, and yield components of no-till rainfed soybean under variable potassium

Spatial soil-K availability for no-till soybean [Glycine max (L.) Merr.] has not been studied extensively. We characterize soybean growth- and yield-component and quantify root parameters as a function of soil depth in K-stratified soils with 1 M ammonium acetate extractable-K ranges 60–290 at 0–10 cm increment and 50–90 mg kg−1 at the 10–20 cm increment. Shoots and roots (five depth increments to 50 cm) were collected during development and grain at harvest during 2 years. Soil K at or above the critical level (104 mg K kg−1) increased early-season leaf area and root K-uptake rates early and late in reproductive development. Greater number of seeds plant−1 increased yield for soils with K near the critical level. Soil-K above the critical level increased luxury K-uptake without improving yield, seed-K concentration and accumulation, or seed oil and protein concentration. Greater root length density (>41% of the total) in surface soil coupled with previous results showing greater water content throughout the season in surface soil compared to deeper layers illustrates K stratification caused by no-till may enhance soybean K-uptake.

Nitrogen rate and plant population effects on yield and yield components in soybean

This research was carried out to determine the effect of plant population and nitrogen rates on yield and yield components in soybean under Bursa, Mustafakemalpa
a ecological conditions. Trials were conducted during 2000 and 2001 at the experimental fields of the Mustafakemalpa
a Vocational High School, University of Uludag. Soybean cultivar A-3935 was tested at four plant densities (70 × 5, 70 × 10,70 × 15 and 70 × 20 cm) and four different nitrogen doses (0, 30, 60 and 90 kg ha-1). Plant height, lowest pod height, number of branches per plant, pod number per plant, yield per plant, harvest index, 100 seed weight and seed yield were researched in this experiment. It was observed that increase in plant density and nitrogen rate increased plant height, lowest pod height, harvest index and seed yield. Otherwise, the number of branches per plant, pod number per plant, yield per plant and 100 seed weight decreased as plant density and nitrogen rate increased.

Densidades de plantas daninhas e épocas de controle sobre os componentes de produção da soja

Este trabalho foi conduzido com o objetivo de determinar os efeitos de diferentes densidades de plantas daninhas sobre os componentes de rendimento da soja, cv. BRS 243-RR. O delineamento experimental foi em blocos ao acaso, sendo os tratamentos constituídos pela combinação entre dez períodos crescentes de convivência das plantas daninhas com a cultura (0, 0-5, 0-10, 0-15, 0-21, 0-28, 0-35, 0-42, 0-49 e 0-125 dias) e três níveis de infestação (baixa, média e alta). Na área de baixa infestação, a comunidade infestante foi composta principalmente por Brachiaria plantaginea, Ipomoea nil, Euphorbia heterophylla e outras. Nas áreas de média e alta infestação destacaram-se Brachiaria plantaginea, Ipomoea nil, Digitaria horizontalis, Cyperus rotundus e outras. B. plantaginea foi responsável pelo maior acúmulo de fitomassa seca em todos os níveis de infestação. Com relação aos componentes de produção, o número de vagens por planta foi o mais afetado pela competição, com reduções de até 58% na área de baixa infestação, 71% na de média infestação e 78% na de alta infestação. O número de sementes por vagens e peso de mil grãos se mostraram menos responsivos aos efeitos de competição; contudo, houve redução desses parâmetros, indicando relação entre o período de convivência e nível de infestação e os componentes de produção da soja.

Soybean Yield and Yield Component Response to Plant Density in Narrow Row Systems

Soybean (Glycine max) yield is responsive to changes in plant population and row spacing under dryland conditions. Soybean seeding rate recommendations in many states were developed prior to the release of herbicide tolerant varieties when soybean seed costs were lower. As a result, many recommendations are high, and soybean performance at low plant densities in narrow rows needs to be reevaluated. This study was conducted to evaluate soybean yield response to plant density in narrow row, drilled systems (7.5 and 15 in) and evaluate the effects of plant population on yield components. The study was conducted in six environments with optimum plant populations ranging from 80 000 to 140 000 plants acre. The two yield components responsible for the yield optimization were pods plant and pods acre. As plant population increased, pods plant decreased steadily; however, yield was not reduced either year of the study by the loss of pods plant because pods acre increased as plant population increased. The optimum seeding rates for each year of the study were below the 150 000 to 160 000 plants acre seeding rate normally recommended in the region. The decreased optimum plant populations in both years did not adversely affect yield and might be useful in reducing input costs in dryland soybean production.

콩에서 수량구성요인과 관련된 양적형질유전자좌의 분석

Seed and pod numbers are the main yield components in soybean. Selection for increased yield potential is main goal of plant breeding. The objective of this study was to identify quantitative trait loci (QTLs) that control pod number per plant, seed number per plant and pod in soybean. The 117 F2:10 recombinant inbred lines (RILs) developed from a cross of 'Keunolkong' and 'Shinpaldalkong' were used. Two independent QTLs for pod number per plant were identified from linkage group (LG) F and L. Two QTLs for seed number per plant were located on LG F and L. Seed number per pod was related with three QTLs located on LG D1a, D1b and F. Pod and seed number per plant have two common QTLs on LG F and L.

Effect of seasonal water stress on soybean and site specific evaluation of CROPGRO-Soybean model under semi-arid climatic conditions

In 2003 and 2004, a study was conducted to determine the effect of different water stress levels (0.0, 0.25, 0.50, 0.75 and 1.0, which was full irrigation) imposed on soybean and to compare with CROPGRO-Soybean model simulations under semi-arid climatic conditions of Harran plain, Sanliurfa, Turkey. Soybean plots were 5 m long with five plant rows of crop with 75 cm row and 4–5 cm plant spacing. Irrigation system used to irrigate soybean plots was a drip irrigation system with 20 cm-spaced emitters with flow rate of 4 L h −1. Soybean growth simulation model used in this study was part of DSSAT v. 3.5 version (Decision Support System for Agrotechnology Transfer). In 2003 and 2004 full irrigated ( I 100) plots had crop ET values of 574 and 619 mm, when simulated ones for the same treatments ranged from 595 to 576 mm, respectively. Measured yields ranged from 322 to 3684 kg ha −1 and 267 to 3952 kg ha −1 for the years of 2003 and 2004, respectively, while simulated results for the same years varied from 616 to 3675 kg ha −1 and 543 and 3690 kg ha −1. Analysis of applied irrigation amounts and observed yields indicated a strong relationship ( P < 0.01). Furthermore, regression analyses of yield data indicated a statistically significant ( P < 0.05) relationship between measured and simulated yields with R 2 values of 0.94 and 0.88 for 2003 and 2004, respectively. Overall, reduction in irrigation water amounts lowered yield in both years and similar results were obtained from simulations. In general, CROPGRO-Soybean model satisfactorily simulated soybean yields and yield components.

EFEITOS DE NÍVEIS E ÉPOCAS DE DESFOLHAMENTO SOBRE O RENDIMENTO E OS COMPONENTES DO RENDIMENTO DE GRÃOS DA SOJA

O objetivo do trabalho foi de avaliar o efeito de níveis e épocas de desfolhamento sobre o rendimento de grãos e componentesdo rendimento da soja, em semeadura direta. O experimento foi conduzido na Estação Experimental Agronômica da UFRGS, na safra 2002/03. O delineamento experimental utilizado foi o de blocos ao acaso com parcelas sub-subdivididas e quatro repetições. Os tratamentos foram desfolhamento em quatro estádios de desenvolvimento (V9 – nono nó, R2 – floração, R5 – início enchimento do grão, R6 – máximo volume de grãos), dois níveis de desfolhamento (33 e 100 %) e testemunha, sem desfolhamento. A cultivar utilizada foi CEP/CD 41, precoce, determinada. A redução do espaçamento entre fileiras de 40 para 20 cm, aumenta o rendimento de grãos mesmo com o desfolhamento. A redução no rendimento, em R2 e R5, foi maior quando as plantas foram totalmente desfolhadas. O estádio mais crítico para perda de área foliar é o R5, decrescendo o rendimento à medida que se intensifica a remoção da área foliar da planta.O componente do rendimento com maior redução, em função do desfolhamento, foi o número de legumes por m2, particularmente com 100% de desfolhamento no início do enchimento de grãos.

Disponibilidade de fósforo e enxofre para a cultura da soja na presença de fosfato natural reativo, superfosfato triplo e enxofre elementar

Este trabalho teve por objetivo comparar o efeito residual do fosfato natural reativo oriundo do Marrocos (Youssoufia) em relação ao superfosfato triplo sobre a produção de biomassa de aveia, produtividade e componentes da produção da soja, disponibilidade de P e de S no solo, bem como os teores destes nutrientes no tecido foliar da soja. O trabalho constituiu de dois cultivos utilizando a cultura da soja e da aveia, realizados em sistema de cultivo mínimo. O delineamento experimental utilizado foi de blocos inteiramente casualizados, com quatro repetições, com os tratamentos arranjados em fatorial 2 x 4 x 3, ou seja, dois fertilizantes fosfatados, fosfato natural reativo (FNR) e superfosfato triplo (SFT), com quatro doses de cada fertilizante (0, 100, 200 e 300 kg ha-1 de P2O5), e três de S (0, 30 e 60 kg ha-1 S elementar). No tecido foliar, determinaram-se os teores de P e S. No solo, nas profundidades de 0-10 e 10-20 cm, determinou-se o P disponível. Os resultados indicam que, para o primeiro ano, não houve superioridade do SFT sobre o FNR para produtividade e massa de 100 grãos. A aplicação de SFT proporcionou teores crescentes de P no tecido foliar; por outro lado, não houve efeito da aplicação de doses crescentes de FNR no teor de P. O teor de S no tecido foliar aumentou tanto pela adição das doses crescentes de P quanto pelas doses crescentes de S para ambas as fontes (SFT e FNR).

EFFECT OF INTERCROPpING SOYBEAN, COWPEA AND GUAR WITH MAIZE ON YiELD AND ITS COMPONENTS.

EFFECT OF INTERCROPpING SOYBEAN, COWPEA AND GUAR WITH MAIZE ON YiELD AND ITS COMPONENTS.

Comparative effects of Apron plus 50DS and soil amendment on the growth, yield and food components of soybean

Comparative effects of Apron plus 50DS (a systemic fungicide) and soil amendment (poultry droppings) on growth yield and food components of soybean (TGX 1485-1D) were studied. Soybean seeds treated with recommended dose of Apron plus 50DS had lower percentage germination when compared to the other treatments while the untreated seeds (control) had the highest percentage germination. Seeds treated with Apron plus and planted on amended soil gave the best performance in terms of development and yield. Biochemical analysis of harvested seeds showed an increase in protein content of seeds treated with recommended dose of Apron plus, planted on amended soil. Seeds treated with less than the recommended dose had the highest percentage carbohydrate content, while untreated seeds planted on amended soil had the lowest carbohydrate content. The control experiment had the highest percentage crude fibre while the lowest was recorded for seeds treated with recommended dose of Apron plus, planted on amended soil. However, there is no significant difference among the treatments in percentage ash and moisture content.

Glomus fasciculatum inoculation improves soybean production

The effects on soybean yield components of inoculation with arbuscular mycorrhizal fungus (AMF) Glomus fasciculatum were investigated at different phosphorus levels. The level of root AMF colonization decreased a little when P levels increased. Mycorrhizal inoculation and increasing levels of P application had positive effects on yield components such as stem and root length, shoot and root dry weight, stem diameter, 1000-grain weight and seed yield per plant but not on legume numbers per plant. Both mycorrhiza inoculation and P treatments affected P and N concentrations of grain and roots of soybean. Mycorrhizal fungi decreased the need of P addition in growth medium by contributing to the demand of optimum phosphorus for growth of soybean.

Propriedades físico-hídricas do solo sob plantio direto escarificado e rendimento da soja

O solo sob plantio direto (PD) sofre alterações ocasionados pela mínima mobilização e pelo tráfego de máquinas. O efeito dessas alterações sobre o desenvolvimento das plantas é dependente das condições climáticas. A escarificação esporádica do solo sob PD tem se apresentado como uma alternativa para minimizar os efeitos da compactação, especificamente em períodos de deficiência hídrica. O objetivo deste trabalho foi avaliar as alterações nas propriedades físico-hídricas de solo sob PD e plantio direto escarificado (PDE) bem como o desempenho da cultura da soja implantada em semeadura direta com dois mecanismos sulcadores na semeadora. O experimento foi instalado em área com seis anos sob PD, sendo que parte da área foi escarificada. Avaliou-se o teor de matéria orgânica, a densidade do solo, a máxima densidade e a densidade relativa, a resistência mecânica do solo à penetração, os componentes de rendimento e rendimento de grãos da cultura da soja. Os resultados indicaram que a escarificação do solo sob PD não afeta o teor de matéria orgânica do solo, diminui a densidade do solo, a densidade máxima, a densidade relativa e a resistência mecânica do solo à penetração. Os componentes de rendimento de grãos da cultura da soja não foram afetados pelos manejos de solo, tampouco pelos mecanismos sulcadores da semeadora. O rendimento de grãos da soja também não foi afetado pelos manejos, mas positivamente pela utilização do sulcador tipo guilhotina em PD.