Soybean growers in the mid-southern U.S. face many challenges imposed by adverse weather conditions that vary spatially and temporally. As a result, growers experience variations in soybean seed quality, grain quality, and yield. While not every harvest season experiences extremes in environmental conditions, those that do may result in major quality issues that could lead to significant financial losses. Therefore, the objective of this research was to evaluate quality as it relates to delayed harvest conditions for soybean following common management practices such as fungicide application to mitigate spread of pathogens or harvest aid application to facilitate more efficient harvest. Experiments were conducted in 2019 and 2020 to determine the impact that these soybean management practices have on soybean quality under delayed harvest conditions. Results indicate that soybean quality, regardless of planting date, was not impacted by fungicide or harvest aid treatment, but rather by harvest delay.

Relatively little change in national soybean (Glycine max) yield over the previous years have led many farmers to creating management regimes focused on plant stress. Field experiments consisting of two different relative maturity (2.8RM and 4.5 RM) soybean cultivars were established at three locations across Kentucky in 2013 and 2014. Each maturity group received a single application, sequential applications, or a combination of the following treatments: N’N-diformyl urea, lactofen, lambda-cyhalothrin with thiamethoxam, and azoxystrobin with propiconazole. Relative maturity and yield environment*treatment interactions were observed to be significant (p 0≤.05). 4.5 RM soybean cultivars yielded significantly greater (800 kg ha-1) than 2.8 RM cultivars. Compared to the untreated check, no treatment in the yield environment*treatment interaction significantly increased yield. Significant yield decrease varied across yield environment, but was observed for treatments containing a combination of lactofen and N’N-diformyl urea. Application of stress management practices was not a consistent approach to improving soybean yield.

Soybeans with large seed size, uniformity, clear hilum, and high 11S/7S ratio are favored for soymilk and tofu making. In order to find ideal soybean lines for food making, sixty-eight soybean lines, which were selected from thousands of accessions in the USDA-Soybean Germplasm Collection, were planted in three successive seasons. Eight lines were identified from twenty-two lines harvested in 2014 (Stoneville, MS) to be suitable for tofu making as judged by chemical composition and sensory quality of tofu. The results provided important food quality information to the growers, breeders and tofu industries for their selection of soybean to improve food quality. In the filled tofu making and texture analysis study, the correlation between A3 subunit percentage and tofu firmness was significant (N=22. r = 0.77, P < 0.001). The result proved that the percentage of A3 subunits could be an indicator for predicting the firmness of tofu.

Soybean (Glycine max L.) is an important legume crop often exposed to heat and drought stresses during reproductive and early-seed setting stages, resulting in lower yields and seed quality. Ten soybean cultivars were phenotyped for individual (drought or heat) and combined stress tolerance. Under drought, reduced stomatal conductance and increased canopy temperature significantly reduced seed number (46%) and weight (35%). Heat stress alone reduced seed number (19%) and weight (23%) compared to control. Moreover, a degree increase in daytime temperature above 32 °C during the reproductive stage reduced seed weight by 4% and 7% under well-watered and drought conditions, respectively. Seed protein was increased under drought, while it declined under heat and combined stress compared to control. In contrast, oil content showed the opposite trend. Weak correlations between phenotypic traits under individual and combined stress suggest that selecting cultivars for individual stress tolerance may not work under combined stress conditions.

A soja geneticamente modificada tolerante ao herbicida glifosato foi testada em ensaio nutricional. A qualidade protéica da soja foi avaliada durante 14 dias de experimento com ratos machos tipo Wistar recém desmamados. Além de um grupo controle aproteico, quatro dietas testadas continham cerca de 10% de proteínas de diferentes fontes: caseína, soja comercial, soja parental e soja GM. Resultados similares entre os grupos demonstraram o baixo aproveitamento da proteína ingerida, conforme esperado para todas as dietas com soja não suplementadas com metionina e expressos pelos valores de PDCAAS. As análises hematológicas realizadas demonstraram a síntese comprometida de células eritrócitárias e imunológicas nos mesmos grupos experimentais. Este comportamento fisiológico dos animais indica que a ingestão da variedade GM não causou diferença significativa no desenvolvimento dos animais entre as três amostras de soja ensaiadas e tampouco foram observados efeitos adversos em órgãos dos animais e nos parâmetros químicos analisados. / A glyphosate tolerant soybean obtained by genetic modification was tested on a nutritional essay. The quality of the soy protein was assessed by a 14-day long experiment with Wistar male rats, three weeks old. Besides the control free protein group, four different diet groups containing about 10 % protein were pooled out: casein, commercial, parental and GM soybeans. Similar results showed the regular low biological value of the consumed soy proteins not supplemented by methionine displayed by PDCAAS values. The hematological analysis pointed to a commitment of the synthesis of erythrocytic and immunologic cells at the experimental soy groups. The overall behavior of the animals indicate the ingestion of the GM variety of soybean did not cause significant differences for the rat development when compared to the other soybean groups, neither side effects on inner organs and chemical analyzed parameters.

A soja geneticamente modificada tolerante ao herbicida glifosato foi testada em ensaio nutricional. A qualidade protéica da soja foi avaliada durante 14 dias de experimento com ratos machos tipo Wistar recém desmamados. Além de um grupo controle aproteico, quatro dietas testadas continham cerca de 10% de proteínas de diferentes fontes: caseína, soja comercial, soja parental e soja GM. Resultados similares entre os grupos demonstraram o baixo aproveitamento da proteína ingerida, conforme esperado para todas as dietas com soja não suplementadas com metionina e expressos pelos valores de PDCAAS. As análises hematológicas realizadas demonstraram a síntese comprometida de células eritrócitárias e imunológicas nos mesmos grupos experimentais. Este comportamento fisiológico dos animais indica que a ingestão da variedade GM não causou diferença significativa no desenvolvimento dos animais entre as três amostras de soja ensaiadas e tampouco foram observados efeitos adversos em órgãos dos animais e nos parâmetros químicos analisados. / A glyphosate tolerant soybean obtained by genetic modification was tested on a nutritional essay. The quality of the soy protein was assessed by a 14-day long experiment with Wistar male rats, three weeks old. Besides the control free protein group, four different diet groups containing about 10 % protein were pooled out: casein, commercial, parental and GM soybeans. Similar results showed the regular low biological value of the consumed soy proteins not supplemented by methionine displayed by PDCAAS values. The hematological analysis pointed to a commitment of the synthesis of erythrocytic and immunologic cells at the experimental soy groups. The overall behavior of the animals indicate the ingestion of the GM variety of soybean did not cause significant differences for the rat development when compared to the other soybean groups, neither side effects on inner organs and chemical analyzed parameters.