AMIN ALI M.
Abstract
The study was evaluated the effects of drought and heat stress on spring wheat (Triticum aestivum, C.V. Chablis) at the
fl owering phase. The potted plants of wheat at the fl owering stage was exposed to drought stress during fi ve days under
high temperature during day/ night temperature of 26/13°C, and low temperature at 15/10°C. After stress period wheat
plants were tested for water potential, and after harvesting for number of ear per pot, grain per year, harvest index, number
of grains per spikelet, weight grains per spikelet and mean weight grain per spikelet. Exposure of plants to drought stress
under high temperature had signifi cantly decreased leaf water potential. Drought in combination with high temperature
reduced signifi cantly the number of ear per pot, grain per year, harvest index, and reduced signifi cantly the number of grains
per spikelet, grains weight per spikelet and mean grain weight per spikelet. The study showed that water stress with high
temperature at 26°C accelerates plant growth and fl owering, but reduces yield components.
Key words:
water stress, water potential, grain weight, grain number and yield