Qualidade fisiológica de sementes de feijão de cultivares de diferentes hábitos de crescimento, em função de densidades populacionais, no Norte de Minas Gerais

Abstract

The objective of this study was to evaluate the physiological quality of seeds of four bean cultivars with different growth habits, depending on sowing rates and sowing dates, under the conditions of the North of Minas Gerais. The experiment was conducted at the Experimental Farm Unimontes, located in the municipality of Janaúba, Minas Gerais, during the harvest and the dry winter of 2011, with analyzes performed at the Laboratory of Seeds Analysis Unimontes, Janaúba campus. The treatments were arranged in a 4x5 factorial scheme, involving four bean cultivars (Ouro Vermelho, Ouro Negro, Madrepérola and Manteigão Vermelho) and five seeding rates (100, 200, 300, 400 and 500 thousand plants ha'). The experimental design was a randomized complete block with four replications. The physiological seed quality was evaluated from the following characteristics: moisture content, germination, first count germination, seedling emergence, speed of emergence and accelerated aging. The data were subjected to analysis of variance, involving the two growing seasons. The effects of planting density were studied by means of regression analysis, and the effects of cultivars were studied by the Tukey test at 5% significance level, while the effects of planting dates were compared by F test at 1 and 5% significance level. The results showed that the seeds of the cultivar Manteigão Vermelho have lower physiological quality than the cultivars Ouro Vermelho, Ouro Negro e Madrepérola, growing conditions in the North of Minas Gerais. The bean crop in the dry season seems more suitable for the production of seeds with high physiological quality. The increase in seeding rate does not affect the physiological quality of bean seeds, regardless of the growth habit of the cultivar.