Phenologyc behavior of different soybean (Glicine max) maturity groups in Uruguay

Temporary location of the critical period

Abstract

The phenology and the temporary location knowledge of the critical period (CP) of yield soybean determination, are aspects to consider in the selection of the cultivar and in the crop management practices definition. The study consisted in characterize the phenology of six soybean maturity groups (MGs) and also in delimiting the CP temporary location at different photoperiods and temperature conditions. The environmental variations was caused by changes in the localities and in the sowing dates (DS). The evaluated DS were: October, November and December and the experiments were done simultaneously in two Littoral localities, for two consecutive years and without water and nutrients limitants. The most important factor to determine the phenologycal behavior was the DS, as the DS were delayed, the cycles in the six MGs were shorten. In the northern localities, were the cycles shorter and CP previous location. In MGs III and IV, the CP temporary location rank proved to be wider and dependent on the DS, instead MGs VII and VIII showed the smallest range of CP location and less DS dependence in the final location of it.