CRESCIMENTO INICIAL DE SOJA EM FUNÇÃO DO VIGOR DAS SEMENTES EARLY GROWTH OF SOYBEAN PLANTS IN RELATION TO SEEDS VIGOR

This work aimed to evaluate the effect of seed vigor on the early growth of soybean plants. An experiment was conducted in two periods (2001 and 2003) at the Experimental Field of the Faculdade de Agronomia “Eliseu Maciel” - Universidade Federal de Pelotas - Brazil. The cultivar BRS 154 was used. A completely randomized block design arranged in split plots with four replications was used. The treatments were two levels of seed vigor (high and low) as the main plots and three periods of plant evaluation (10, 20, 30 days after emergence) in 2001, and four periods of plant evaluation (07, 14, 21 and 28 days after emergence) in 2003, as the subplots. The plants from the high seed vigor showed the highest leaf area and dry matter production in the periods evaluated. High seed vigor increased crop growth rates from 10 to 30 days after emergence in 2001 and from 21 to 28 days after emergence, in 2003; and also the metabolic efficiency from 10 to 20 days after emergence in 2001. Plants from the high seed vigor have higher leaf area and dry matter production. High seed vigor increased crop growth rates from 21 days after emergence.