Tamara Pereira

Capacidade de cocção de grãos de feijão em função do genótipo e da temperatura da água de hidratação

Objetivou-se, neste trabalho, avaliar o efeito da temperatura da agua de embebicao sobre a capacidade de hidratacao/coccao, e se a hidratacao pode ser um indicativo do menor tempo de coccao em graos de feijao. Foram utilizadas 5 cultivares de feijao: Rubi, Uirapuru, Perola, Valente e Campeiro, produzidas em lavouras comerciais em Lages SC, no ano agricola 2005/2006. Os graos recem-colhidos foram padronizados para 12% de umidade e analisados quanto ao tempo de hidratacao, capacidade de hidratacao e tempo de coccao. O aumento da temperatura da agua de embebicao proporcionou aumento na capacidade de hidratacao diferentemente para as cultivares com temperatura superior a 25oC, Perola demorou em torno de 8 horas para atingir a maxima hidratacao, enquanto que Rubi, nessa mesma condicao, nao atingiu a maxima hidratacao. A analise de correlacao mostrou que apenas para as cultivares Campeiro e Rubi a rapida absorcao de agua pelos graos e um indicativo de maior rapidez na coccao, mas uma correlacao negativa foi observada para Uirapuru. Com base nos genotipos avaliados, e improvavel fazer uma padronizacao unica das condicoes previas ao cozimento que valha para todas as cultivares, ou seja, ha a necessidade de uma caracterizacao mais detalhada e especifica para cada genotipo em estudo.

PHYSIOLOGICAL QUALITY OF SOYBEAN SEEDS DEPENDING ON THE PREHARVEST DESICCATION

Depending on the cultivar, the use of desiccants in the preharvest can favor maintenance of physiological quality. The objective of the study was to assess the physiological quality of soybean seeds as due to the use of apreharvest desiccant and desiccation time in two harvests (2011/12 and 2012/13). The treatments were five soybean cultivars, two growth stages of application, a control (without desiccant application), and three desiccants (glufosinate-ammonium, carfentrazone-ethyl and paraquat) (2011/12 harvest). In the 2012/13 harvest the carfentrazone-ethyl desiccant was replaced by diquat. The physiological quality of seeds was assessed by the percentage of viability and vigor (cold test, tetrazolium test and accelerated aging test). In 2011/12 harvest, there was an early harvest in six days with the use of glufosinate-ammonium and paraquat desiccants, when desiccation was done in stage R7.1, with maintenance of seed quality; however it was dependent on the cultivar. In the 2012/13 harvest there was no early harvesting due to the presence of rain in the preharvest and the use of desiccation did not affect the physiological quality of the seeds either. Cultivar NA5909 RG was more tolerant to remaining in the cultivation environment and maintained higher viability than 90% and greater vigor of 71% by the cold test compared to cultivar BMX Turbo (2011/12 harvest). It is concluded that desiccation can be a viable alternative to the soybean early harvesting, but it depends on the cultivar, the time of desiccation, the active principle of the desiccant and the absence of rain in preharvest.