A greenhouse experiment was carried out to study the effect of simulated water stress during different growth stages on the yield of the early soybean cultivars Paraná, in Campinas, State of São Paulo, Brazil. The water stress was simulated by the addition of PEG (polyetilenoglycol) to the Hoagland nutrient solution where the plants were cultivated, up to three different stages: vegetative period, flowering period and pod filling period. It was observed that water stress during the three periods reduced the grain yield, the seed weight and the seed number. The water stress was more damaging during the reproductive stages for the cultivars studied since it reduced the grain yield.
soybean; Glycine max (L.) Merrill; water deficiency; production