The lack of complete information on the yield potential for different soybean cultivars is the major limiting factor for the utilization of agrometeorological models to predict crop yield. A model proposed by FAO was modified including a factor refering to excess of rainfall. Estimates of potential yield was made, as a function of planting date of experiments conducted at Ribeirão Preto Experimental Station during eight consecutive years using the main soybean cultivars grown in the State of São Paulo. The cultivars IAC-8, IAC-10, IAC-11 and IAC-12 showed greater yield potential when sowed in September-October. The IAC-11 showed the yield potential of up to 5,500kg/ha. On the other hand the cultivars Santa Rosa, IAC-13 and Paraná showed higher yield potential when sowed in October-November.
potential yield; soybean cultivars; agrometeorological model; water balance