Evaluation of chickpea genotypes responses to supplementary irrigation in Maragheh region

IntroductionChickpea (Cicer arietinum L.) is the most important field crop among the food legumes in Iran. According to the published statistic by agricultural ministry of Iran, about 90% of planting areas of chickpea is under dryland conditions. In Iran, chickpea is often cultivated in areas with limited rainfall or soil moisture and drought is always a potential problem for its production. From the importance issue, drought stress is the second abiotic stress that affect on chickpea yield. Also drought stress is the most important factor which reduces food legume crops production (especially chickpea, lentil and pea) under dryland conditions of west Mediterranean and North Africa regions. Limiting or cutting of regional rainfalls at the end growing season time and existing of drought damage in flowering time is one of the most important limitations in chickpea cultivation under dryland conditions that have highly negative effect on chickpea yield and reports show that, the yield of chickpea is low in these regions. Suitable field management for using from the existing water in order to reduce drought stress damages, increase the yields of crops under dry and semi dry regions. Results of studies show that, using from supplementary irrigation in chickpea increase the total dry biomass, leaf area index, plant height and finally increase its yield under drylands. Also researchers reported that, flowering stage and pod filling period are the most important stages for application of supplementary irrigation in order to reducing of drought severity in food legumes. Materials & MethodsThis study was performed to evaluate the effects of supplementary irrigation on some agronomic traits and grain yield of four chickpea genotypes. The experiment was conducted for three consecutive seasons during 2010-13 under field condition in Maragheh Dryland Agricultural Research Station (Latitude 37°15′ N, Longitude 46°15΄ E, and Altitude 1720 meter above sea level). The main plots were irrigation three-time (irrigation at planting, irrigation at planting and flowering times, and irrigation at planting, flowering and pod filling period). Each irrigation treatment included 40 mm water application in the experimental field. The sub plots were four Kabuli chickpea genotypes (Azad, Arman, ILC482 and a Turkish landrace from Van city). The soil of the experimental site is clay-lome, and the climate of the station is cold and semi drought with mean long term annual rainfall 360 mm, and with mean maximum and minimum absolute temperature about 37°C and -25°C in summer and winter, respectively. The mean annual air temperature in station is 9.3°C. Each experimental plot was 6 planting rows with 6 meter length and 25 cm distance between two rows. Some agronomic traits such as number of days from planting to 50% of flowering and maturity, pod filling period, plant height, 100 seed weight, dry biomass, grain yield, harvest index and productivity score of genotypes were noted and analyzed by MSTAT-C program. The comparison of means method was Duncan’s Multiple Range Test in 5% probability level. Results & DiscussionCombined analysis of variance showed that the year factor had significantly affected in all studied traits. The effect of irrigation times was significant on all traits except 100 seed weight, harvest index and productivity score. There were significantly differences among the genotypes in plant height, 100 seed weight, grain and dry biomass yields, harvest index and productivity score. The interaction of year×genotype significantly affected on all traits except plant height, dry biomass weight, harvest index and productivity score. Results showed that interaction effect of irrigation time by genotype was significant on seed and dry biomass yields. It shows that different studied genotypes had different responses to supplementary irrigation times. The highest seed yield and dry biomass in all studied genotypes belonged to three-time irrigation. Azad cultivar seed yield under irrigation at planting time and flowering stage time was 1029 Kg.ha-1 that comparing with its yield under irrigation only at planting time (648 Kg.ha-1) increased about 58.8%. It was the highest increasing in response among all studied genotypes for this treatment. The lowest response (increasing seed yield) under two-time irrigation (planting time+flowering time) belonged to Turkish landrace and was 28.9%. In comparison of genotypes seed yields between one time irrigation treatment (irrigation at planting time) and three-time irrigation treatment (irrigation at planting+flowering and pod filling period) the highest and lowest increasing (71.6% and 51.3%) belonged to Arman cultivar and Turkish landrace, respectively. The interaction of year×irrigation time×genotype had not significantly effect on studied traits. The highest seed yield (1064 Kg.ha-1) belonged to the three times irrigation treatment. Among the studied genotypes, the highest seed yield (939 Kg.ha-1) belonged to ILC482. ConclusionIn conclusion and based on the results it would stated that, application of 40 mm irrigation increases grain yield and improve most of the agronomic traits in spring cultivation of chickpea crop under Maragheh dryland condition.