Growth and yield of wheat (Triticum aestivum) under deficit irrigation

Abstract

Timing and the extent of water deficit were studied in a field experiment on wheat (cv. Shatabdi) for three consecutive years from 2003-04 through 2005-06 at Jamalpur area. The effects of number and timing of irrigation application on yields were investigated under variable soil moisture condition in the root zone of different treatments. Eight deficit irrigations, including one no stress and one rainfed treatments were selected to subject the crop to various degrees of soil water deficit at different stages of crop growth. Measured amount of irrigation water was applied as per schedule prescribed for a particular treatment. Grain yield (GY), biomass, harvest index (HI), and water productivity (WP) were reasonably affected by deficit irrigation. Other yield contributing parameters like 1000-grain weight, grains/spike and spike, length were also affected by different levels of deficit irrigation. During grain formation stage, water deficit did not affect the grain yield but saved water significantly. Such water deficit treatments also shortened the grain maturation period. Differences in grain and straw yield among the stressed and no stress treatments are comparatively small, and statistically insignificant in some cases. The highest water productivity (2.02 kg/m3) was observed in treatment which was irrigated only once at crown root initiation stage (T2) although the yield was comparatively low. The CRI (crown root initiation) stage was found the most sensitive to water stress. Water stress at vegetative stage also reduced the yield considerably. DOI: http://dx.doi.org/10.3329/bjar.v38i4.19663 Bangladesh J. Agril. Res. 38(4): 719-732, December 2013