Water deficit during panicle development in pearl millet: yield compensation by tillers

Abstract

SUMMARY: Water deficit during the panicle development stage reduced the grain yield of the main shoot panicle of pearl millet but this loss was compensated by increased grain yield of the tillers. The potential extent of compensation in grain yield components by tillers was investigated by removing the main shoot at panicle initiation (PI) and flowering stages respectively, for both irrigated and water-stressed plants. Grain yield loss by removal of the main shoot of plants at PI was fully compensated by tiller grain yield in both the irrigated and water-stressed plants. The compensation was, however, only partial when the main shoot was removed at flowering. The compensation for the grain yield loss in the main shoot due to either water stress or removal was through an increase in number of grains on the tillers. This increase was due to an increase in the number of productive tillers in the case of water stress and to both an increase in the number of productive tillers and an increase in the number of grains per panicle in the case of main shoot removal. This compensatory mechanism by tillers plays an important role in overcoming the effects of pre-flowering water stress damage to the main shoot.