EFFECT OF WATER AVAILABILITY AND TEMPERATURE ON THE GENOTYPE-BY-ENVIRONMENT INTERACTION OF PEARL-MILLET IN SEMIARID TROPICAL ENVIRONMENTS

Grain yields in drought-affected environments are often characterized by large genotype-by-environment (GE) interactions, caused by a highly variable timing and intensity of stress occurrence. The aim of our st udy was to assess the effectiveness of simple meteorological environme ntal descriptions in providing an understanding of the environmental c ontribution to the GE interaction of pearl millet (Pennisetum glaucum (L.) R. Br.) in the semi-arid tropics. The experiment comprised fourte en genotypes, grown across 24 environments in India. Data on water ava ilability throughout the season and maximum temperatures during grain filling were used to describe the environments. Escape from drought an d heat stress were the major factors determining the GE interaction. B oth the timing and intensity of stress occurrence were important. Know ledge of the environmental causes of the GE interaction may facilitate the identification of adaptive plant traits, and may also enable a mo re rational choice of test locations for breeding programs.