Effect of irrigation cut from initiation of flowering and podding till maturity on yield and its components in prevalent chickpea cultivars in Kermanshah region

Chickpea (Cicer arietinum L.) is the third most important grain legume in the world and the second grain legume in the Mediterranean environment including Iran. Average of chickpea grain yield in Iran is about 500 Kg ha−1 while in the world this average is 900 Kg ha−1.These data indicate the importance of research on chickpea. Water deficit stress is one of the most important factors in reducing grain yield of chickpea in the Mediterranean region. In such areas, water shortage almost take place at flowering and post flowering period. Generally, water deficit stress with decreasing plant photosynthesis and consequently reducing the production of photosynthetic products, the process of plant growth and development caused reduction of plants economic grain yield. In chickpea, flowering and podding stages are the most sensitive growth stages to water deficit and water shortages in these stages result in a significant reduction in grain yield. Hence, the present study was conducted to investigate the resistance of commonly chickpea cultivars used under cultivation in Kermanshah region in different water deficit stress conditions from the beginning of flowering and podding until maturity time.

In order to investigate the effect of post anthesis water deficit on yield and its components in different chickpea cultivars, a split-plot experiment based on complete block design with three replication conducted in research filed and labs of agronomy and plant breeding department of Razi university. The main factor was the moisture regime with three levels included: 1) control, 2) Irrigation cut from flowering till maturity and 3) irrigation cut from podding till maturity. Sub-factor consisted of different chickpea cultivars (Arman, Azad, Bivanij, Hashem and ILC482). Sowing was done manually. Each plot was consisted of six rows with three meters in length and with a spacing of 25 cm and 10 cm seeds space on the row. Harvesting was performed when each cultivar were matured under control and water deficit treatments and different traits was evaluated. These traits consist of: grain yield, biomass, straw yield, harvest index, number of pod per plant, number seed per pod, number of seed per plant, and 100 grain weight. Correlation coefficients between different traits under different water regime were estimated. The obtained data were exposed to analysis of variance (ANOVA). Means comparison was done using Duncan's new multiple range test (DMRT) using MSTAT-C software. Correlation coefficients between traits were estimated with SAS software ver. 8.0 (SAS Institute Inc., Cary, NC, USA).

 According to the results, water deficit at both levels, significantly reduced the grain yield, biomass, harvest index, 100 seed weight, number of seeds per plant and pod and number of pods per plant. The highest reduction in grain yield and biomass under water deficit from beginning of flowering till maturity was observed with about 51 and 36 percent, respectively. Under control condition, the highest grain and biological yield in Arman cultivar was 1355 and 3126 Kg ha-1, respectively. In application of water deficit from the beginning of podding until maturity, the highest grain and biological yield in Azad and Bivanij cultivars was 1035 and 2570 Kg ha-1, respectively and under water deficit stress from the beginning of flowering until maturity the highest grain and biological yield in ILC482 cultivar was 715 and 2000 Kg ha-1, respectively. Also, according to the results of correlation analysis, there was a positive and significant correlation between grain yield and biological yield, harvest index, number of pods per plant and number of seeds per plant. Azad, Bivanij and ILC482 cultivars showed better performance at both levels of moisture stress. Regarding the occurrence of moisture stress in the studied area at flowering and podding time in spring planting, spring cultivation of these cultivars is more desirable.

The results of this study showed that Azad, Bivanij and ILC482 cultivars were resistant to drought stress and their yield reduction was less than Arman and Hashem cultivars, also it is recommended that the Hashem cultivar dose not cultivate in spring at Kermanshah region. Generally, more resistant to drought varieties were more capable of water management which also improved the process of photosynthesis and helped to maintain better functionality in these conditions