Plants subjected to drought at the early vegetative stage displayed similar physiological characters subsequently under well-watered conditions as compared with control. Photosynthesis rates decreased with decrease in stomatal conductance, but a weak relationship between them implied that non-stomatal limitations to photosynthesis might have been in operation. In Bangladesh wheat is grown generally after the harvest of aman rice on residual soil moisture. The growing season is characterized by low rainfall and relatively high evaporative demand. Crop grown without irrigation during the dry season thus encounters drought stress of varying degrees at different growth stages.
Drought is probably the most important factor controlling crop yield worldwide.
This study was undertaken to investigate the photosynthetic rate and leaf gas exchange characteristics of wheat under different levels of drought stress. Ten seeds were planted per pot, and one week after emergence the seedlings were thinned to three seedlings per pot. There were 160 pots, with 40 pots assigned to each cultivar. The plants were subjected to four levels of water regimes. Botanical Bulletin of Academia Sinica, Vol.