Drought is one of the major constraints for soybean production in Brazil. Seed yield of ten Brazilian soybean cultivars shetered from rain (dorught stress) for one month after the first flowering was examined over two growins seasons in the field in Londrina, Brazil. The drought tolerance on the basis of seed yield varied higher drought tolenrance, crop growth rate (CGR) during the drought stress period was higher than on other cultivars.
They also maintained a larger leaf area during the stress period. although reproductive development was retarded by drought stress, it tended to be retarded less in drought-toleran cultivars. The information obtained in this research may be useful for breeding drought-tolerant cultivars or selecting diverse germplasms for soybean cultivars.