INFLUENCE OF WATER-DEFICITS ON PHENOLOGY, GROWTH AND DRY-MATTER ALLOCATION IN CHICKPEA (CICER-ARIETINUM)

Quantitative understanding of the response of phenology and crop growth to environmental factors is required to build yield-prediction models. Field experiments were conducted to study the influence of water-deficits on phenology, growth and dry-matter allocation in chickpea (Cicer arietinum L., cv. JG 74). The crop was subjected to increasing intensities of water deficits during both vegetative and reproductive phases by applying gradient irrigations. Durations of emergence to flowering (E-FL), flowering to beginning of pod-fill (FL-BPF), and beginning of pod-fill to physiological maturity (BPF-PM) were inversely correlated with normalized evapotranspiration-deficit (E(t)-deficit) experienced by the crop during a growth period. In terms of thermal time (base temperature = 8-degrees-C, ceiling temperature = 30-degrees-C), the durations of E-FL, FL-BPF, and BPF-PM phases decreased by 4.5, 3.1, and 3.8-degrees-Cd for each mm kPa-1 of normalized E(t)-deficit, respectively. Water-deficits prior to flowering decreased canopy development, light interception, and dry-matter production to the maximum extent compared with stress after flowering. Water-deficit prior to pod-initiation did not influence the allocation of dry-matter between leaves and branches, but water-deficit during the reproductive phase increased allocation to the reproductive organs. Normalized E(t)-deficit of 1 mm kPa-1 increased allocation to the pods by 0.75% of the biomass produced after pod-initiation and to the seeds by 0.52% of the biomass produced after BPF. It is concluded from this study that we need to consider the influence of water stress on phenology, growth and dry-matter allocation in chickpea in addition to other environmental factors affecting these processes.