Desempenho de sementes de genótipos de soja com grupos de maturação contrastantes em função da época de semeadura

Abstract

In order to produce high quality soybeans, climatic conditions such as mild temperatures and water availability during their formation, filling and maturation are indispensable. As strategies to try to make these conditions feasible, the sowing season and maturation group of the genotypes, as well as genetic factors, such as lignin in the integument, stand out. The objective of this work was to evaluate the effect of sowing season and maturation group of different soybean genotypes, as well as lignin concentration in the tegument, on the physiological quality of the seeds produced. Seed production was carried out in the Experimental Area of UTFPR-DV, in the 2016/17 (Trial 1) and 2017/18 (Trial 2) crops, with three sowing dates: late September, late October and late of December, and eleven soybean genotypes, from different maturation groups. After being harvested, the already cleaned and dried seeds were sent to the Laboratory of Seed Analysis of the University, where the germination, accelerated aging and mechanical damage tests were carried out. In addition, the concentration of lignin in the seed coat was determined by the Seed Chemistry Laboratory - Seed and Grain Technological Center, Embrapa Soja, Lodrina/PR. The experimental design was completely randomized, with four replications. After its compilation, the data set was tabulated and submitted to the Lilliefors test to verify the homogeneity of the variance. Then, ANOVA was performed to verify the significance level of the isolated factors and their interaction (soybean genotypes vs. sowing times) by the T test (p <0.05). Therefore, was compared the means by the Scott Knott test, at 5% probability. In both crops, the best sowing season, aiming seed vigor, was the end of October, for most cultivars evaluated; mechanical damage did not affect seed quality; the lignin content was higher in TP and IAC lines, but with no positive effect on seed quality. Hard seeds were only observed in the IAC and TP lines. Germination of soybean seeds in Trial 1 was better at the December sowing season. And in Trial 2, it was in October. In general, the cultivar NS 4823 RR with GMR 4.8, presented good germination in the two harvests.