Multiplication of Soybean Seeds at Low Seeding Rates

Resumo

The genetic seed produced by the breeder is far from enough to supply the market demand, a problem that can be faced with a two-way approach: increasing the area of multiplication, and/or increasing the seed-multiplying factor. Testing the limits of low seeding rates to determine the resulting increase in individual plant seed production is an extremely useful trait for breeding programs as well as for seed production. The aim of this work was to establish the multiplication factor for soybean seeds resulting from stands obtained from low seeding rates. Stands of 35, 50, 65, 80, 95, and 110 thousand plants per hectare of soybean cultivar BMX Potência RR were displayed in a completely randomized block design, assessing seed yield, yield components and the physiological quality of seeds. Soybean seed yield from low stands treatments did not compromise the physiological quality of the seed produced, however, the higher seed potential of individual plants did not compensate for the lower seed yield per area obtained compared to that of seed rates close to the optimum. For each 15-thousand per hectare stand increase we observed an increase of up to 405 kg (16 % in average) for the range of seed rates studied, however, the seed multiplication factor decreased at a rate of 9 % per each 15-thousand plants per hectare.