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

摘要

The objective of the present work was to evaluate the influence of high- and low-vigor soybean seeds on the agronomiccharacteristics, yield components and seed yield of individual plants and plant communities grown in rows containing differentproportions of high- and low-vigor seedlings. The experiment was conducted in the county of Selbach-RS, Brazil, in the 2012/2013crop year using the short-cycle soybean cultivar FPS Urano RR. The experimental design was completely randomized, with fivereplications. 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% HVand 83.3% LV); and T7 (100% LV), where HV and LV indicate high and low vigor, respectively. Based on the results obtained, it wasfound that: plants originating from high-vigor seeds were taller than low-vigor plants at the V5 and R8 phenological stages; evenwhen populations originated only from seeds with low vigor, yield levels did not reach those found for high-vigor seeds; values ofthousand 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 formedonly by low-vigor seeds.