Correlação entre testes para avaliação da qualidade de sementes de algodão e a emergência das plântulas em campo

Abstract

Cotton seeds (Gossypium hirsutum L.) from the varieties IAC-20 RR, CS-50, DP-20, DP-90 A and DP-90 B acid-delinted were stored during 12 months, under environment conditions. The seed quality was evaluated before storage and at each three months, by using the following tests: germination, classification of plant vigor, precocity of the primary root emission, accelerated aging, germination at low temperature, seedling emergence in the field and electrical conductivity. When the field conditions were closer to the ideal ones, the results obtained in the germination test presented a higher correlation with the seedling emergence in field. Under adverse conditions, however, the seed vigor obtained by germination at low temperature presented a higher correlation with plant emergence in field. According to multiple regression analysis the germination test showed to be the most adequate for estimation of the seedling emergence in the field, but the inclusion of the results from the germination tests at low temperature as well as of classification of the seedling vigor and electrical conductivity contributed for estimating the seedling emergence in the field, so elevating the determination coefficient up to. Index terms: Gossypium hirsutum, seed, vigor, seedling emergence.