EFFECT OF DROUGHT STRESS DURING GRAIN FILLING IN NEAR-ISOGENIC TALL AND DWARF HYBRIDS OF PEARL-MILLET (PENNISETUM-GLAUCUM)

The susceptibility to drought stress during flowering and grain filling of dwarf hybrids of pearl millet carrying the dwarfing gene d2 was investigated in 1987 at Patancheru, India, under field conditions during the dry season and, in the rainy season, under a rain shelter, using four pairs of near-isogenic tall and dwarf hybrids. Drought stress during grain filling reduced the number of grains per unit area and individual grain mass. Grain yields of the dwarf hybrids were lower than those of the corresponding tall hybrids in the unstressed control and under drought stress and were associated with a lower individual grain mass in the dwarf lines. In the dwarf hybrids, harvest index was similar to or better than that of the tall versions but a reduced biomass resulted in lower grain yields. Dwarf hybrids were not more adversely affected by water stress, however, than their tall counterparts, indicating that susceptibility to drought stress would not be likely to limit acceptance of new dwarf varieties.