Individual and population behavior of soybean plants grown in rows with different proportions of high- and low-vigor seeds

Abstract

The objective of the present work was to evaluate the influence of high- and low-vigor soybean seeds on the agronomic characteristics, yield components and seed yield of individual plants and plant communities grown in rows containing different proportions of high- and low-vigor seedlings. The experiment was conducted in the county of Selbach-RS, Brazil, in the 2012/2013 crop year using the short-cycle soybean cultivar FPS Urano RR. The experimental design was completely randomized, with five replications. Seven different proportions of high and low seedling vigor distribution along the growing line were selected: T1 (100% HV); T2 (83.3% HV and 16.7% LV); T3 (66.6% HV and 33.3% LV); T4 (50% HV and 50% LV); T5 (33.3% HV and 66.6% LV); T6 (16.7% HV and 83.3% LV); and T7 (100% LV), where HV and LV indicate high and low vigor, respectively. Based on the results obtained, it was found that: plants originating from high-vigor seeds were taller than low-vigor plants at the V5 and R8 phenological stages; even when populations originated only from seeds with low vigor, yield levels did not reach those found for high-vigor seeds; values of thousand seed weight and number of pods per plant with one seed did not differ between high- and low-vigor seeds, individually; the yield components number of seeds and seeds per plant contributed most to increase yield for the vigor proportions studied; and populations formed only of seeds with high vigor exhibited a seed yield per area 21% (928 kg ha -1 ) greater than that formed only by low-vigor seeds.