Evapotranspiration and yield of irrigated chickpea

Field experiments were conducted during the 1986 and 1987 post-rainy seasons to relate total above ground dry matter (TDM) and seed yields of chickpea (Cicer arietinum L. cv JG 74) with evapotranspiration (ET). The crop was subjected to various degrees of water stress by applying gradient irrigations during three growth phases: emergence to 50% flowering; 50% flowering to 50% beginning pod-fill; 50% beginning pod-fill to physiological maturity. Analysis of the 2-year pooled data showed that across seasons both total dry matter and seed yields were more strongly correlated with normalized ET (R2=0.92, P < 0.01 for TDM, and R2=0.82, P < 0.01 for seed yield), defined as ratio of actual ET to saturation vapour pressure deficit of air, than with actual ET (R2=0.56, P < 0.01 for TDM, and R2=0.40, P < 0.01 for seed yield). Partitioning of total normalized ET observed during the season into normalized ET observed during two or three growth phases of chickpea and regressing seed yield against them did not improve the predictability of models. It is concluded from this study that both total dry matter production and seed yield responses of chickpea to water management can be predicted if the normalized ET during the season is know