Physiological quality of soybean seeds produced under different spatial arrangements of plants

Abstract

The present study aimed to evaluate the physiological effect of seeds on soybean genotypes in the southern region of Rio Grande do Sul. The test was developed in the field, in two agricultural crops, on a farm located in the District of Monte Bonito - Pelotas (RS, Brazil), in eutrophic haplic planosol soil, with geographic coordinates 31° 40' 27"S and 52°23' 28 "W. The experiment consisted of twelve treatments involving two factors: factor A - 3 soybean genotypes (NA 5909 RR (super early, growth indeterminate and maturation group A), NS 6006 IPRO (high grain weight, growth indeterminate and maturation group B 5.9), and NS 5959 IPRO (precocity, indeterminate growth and maturation group C) and factor B - 4 line spacing (0.17; 0.30; 0.45 and 0.60 meters). The experimental design used was randomized blocks in a factorial scheme (3x4) with four blocks. The plant population used was 330.000 plants ha-1. The evaluations of the physiological performance of seeds were germination, first germination count, length and dry matter of aerial part, root, and a total of seedlings, accelerated aging, and emergence in the field. Soybean plants better distributed in the cultivation area, in spacings of 0.17 and 0.30 meters, present greater plant height, stem diameter, and productive performance.the only genotype that presented a reduction in germination as the row spacing increased was 'NS 6006 IPRO', resulting in seeds with lower germination in the spacings of 0.45 and 0.60 m compared to the other genotypes under study. The reduction in the spacings, 0.17 and 0.30 meters, produced seeds with better physiological quality, evidenced in years with rain preceding the harvest.