Drought stress mitigation using supplemental irrigation in rainfed chickpea (Cicer arietinum L.) varieties in Kermanshah, Iran

An experiment was carried out in 2007 to investigate the effects of different irrigation regimes, and chickpea cultivars on chickpea production in the Agricultural Research Station, College of Agriculture, Islamic Azad University, Kermanshah Branch, Iran. The experimental design was split-plot with three replications. Supplemental irrigation at three levels, that is, control treatment (without irrigation) (I sub(0)), one time irrigation at 50% flowering stage (I sub(1)) and one time irrigation at pod-filling staged(I sub(2)), was allocated to main plots and the varieties ILC-482 (V sub(1)), Hashem (V sub(2)) and Arman (V sub(3)) were allotted to sub plots. A significant difference was observed between irrigation treatments in terms of grain yield, plant height, number of axillary branches, distance to the first pod from soil surface, number of grain per plant, number of pod per plant, biological yield, harvest index and 100-grain weight. Such differences were also observed between testing varieties in terms of all traits rather than 100-grain weight. Grain yield was significantly higher for Arman than that of Hashem which was significantly higher than that of ILC-482. Of course, there was no significant difference between Hashem and ILC-482 in terms of grain yield. Arman had the highest values of the number of grain per plant and the highest pod per plant pertained to Arman and Hashem, respectively. High rate of grain yield in irrigation treatment at pod-filling stage was associated with yield components, especially with the number of pod per plant and 100-grain weight. Grain yield was positively correlated with number of pod per plant (r = 0.654**), number of grain per plant (r = 0.902**) and 100-grain weight (r = 0.707**). This research showed that pod-filling is the most sensitive stage to drought stress, and under water limitation conditions, we can considerably increase grain yield at this stage by one time irrigation, especially forArmancultivar.