The soybean seedling emergence is a function of the hypocotyl, responsible for the cotyledon elevation above the soil surface. The greater the hypocotyl length and diameter, the greater the seeddlings’ capacity to emerge and overcome the resistence do to the soil surface crusting. The purpose of this work was to evaluate the hypocotyl length and swelling index (HSI) of soybean cultivars in different seed size. The experiment was performed at the Faculdade de Agronomia da Universidade Federal do Rio Grande do Sul (FA/UFRGS). The hypocotyl length and HSI was determined in seventeen cultivars in three seed sizes (> 6.3mm; between 5.6 and 6.3mm and between 4.75 and 5.6mm in diameter). The cultivars had an average hypocotyl length between 8 and 11cm. The larger seeds produced seedlings with shorter hypocotyls, compared to medium-sized or small seeds, which produced longer ones. The hypocotyl HSI increased with the increase in seed size.
Glycine max (L.) Merrill; emergence; seed size
