Effect of nitrogen and supplemental irrigation on yield and yield components of chickpea (Cicer arietinum L.) cv. Azad

Introduction Currently, the population growth and low protein content of cereals, has attracted the attention of people to legumes nitrogen fixing bacteria in their roots, are effective on soil fertility and after harvest of these products, large amounts of nitrogen will be added to the soil (Majnoon hosseini, 1993). Among legumes, chickpeas (Cicer arietinum) with cultivated area about 11 million ha and production of 650 kg/ha (kochaki et al., 2004), has more adaptations than the climatic conditions of the country, especially with the most dry farming areas of Iran compared to other legumes (Bagheri et al., 1997). Generally, legumes are highly sensitive to water deficit stress (Labidi et al., 2009). Gan et al. (2004) have mentioned that chickpea seed yield decreased by 50% when stressed during pod formation and 44% when stressed during flowering. In different crops as well as in chickpea, differential genotypic response to drought stress as a result of variation in physiological parameters has been reported (Gunes al., 2008). Drought stress is the most important challenges in production of chickpea in Golestan province. On time using of water in the most sensitive stage of plant growth will result in higher production yield. The aim of this study was to evaluate the effect of nitrogen and supplemental irrigation on quantity and quality traits and nitrogen percent of Azad cultivar of chickpea. Materials and methods In order to study the effect of nitrogen and supplemental irrigation on yield and yield components of Azad cultivar of chickpea, an experiment as factorial based on RCBD in three replications was carried out in farm of Gonbad Kavous University in 2015-2016. Two factors was nitrogen in three levels of none consumption, consumption of 25 and 50 kg nitrogen/ha and supplemental irrigation in three levels of none irrigation, irrigation at flowering stage and irrigation at flowering + seed filling stages. Row spacing was 30cm and 10 cm between plants in the each row. Each plot contained four rows of 4 meters. To determine the grain yield, border rows and 0.5 meters rows from both sides of the excluded middle and the rest were harvested. To determine yield components 10 plants were randomly collected and traits were measured. Results and discussion: The results analysis of variance (mean squares) showed that effect of nitrogen and supplemental irrigation on traits of number of pods per plant, number of seeds per plant, 100-seed weight, grain yield, plant dry weight, harvest index and protein yield was significant at 1%. Effect of nitrogen on trait protein percent was significant at 5% and supplemental irrigation was no significant on trait protein percent. The maximum seed yield and protein yield was obtained from consumption of 50 kg N respectively with 3346 and 793/8 kg/ha. The minimum seed yield and protein yield was obtained from non consumption of N respectively with 1880 and 412/9 kg/ha. The maximum seed yield and protein yield was obtained from irrigation at flowering + seed filling stages respectively with 2923 and 649/7 kg/ha and the minimum seed yield and protein yield was obtained from none irrigation treatment respectively with 2199 and 515/9 kg/ha. Irrigation at flowering + seed filling stages produced the greatest amount of yield components. Nitrogen consumption increased all traits. The maximum and the minimum harvest index of chickpea belonged to 50 kg N/ha and none consumption of nitrogen, respectively. Conclusion The results showed that all traits except protein percent were released under the influence of nitrogen and supplemental irrigation. All traits were increased by nitrogen application. The most amounts of traits related to irrigation at flowering + grain filling stages and then irrigation in flowering stage. High amounts of yield components in this treatments increased seed yield.