The effect of humic acid, density and supplementary irrigation on quantity and quality of local chickpea (Cicer arietinum L.) of Neishabur

Legumes are from important food and feed resources with rich of protein for human and animals. Pulse seeds by having 18-32% protein have important role in human food regim specially in low input human feeding (Majnoun Hosseini, 2008). Nayyar et al (2006) have believed that flowering and pod setting stages are the sensitive stages of chickpea to drought and water stress at flowering stage with reducing of flowers fertility will reduce number of seeds per plant. Gad et al. (2012) reported that spraying of humic acid increased seed yield, 1000-seed weight and protein percent of peas. The aim of this study was to determine effect of density, supplementary irrigation and humic acid on quantity and quality of local chickpea )Cicer arietinum L. (of Neishabur.   Materials and methods In order to study the effect of humic acid, density and supplemental irrigation on yield, yield components, protein percent and yield of local chickpea (Cicer arietinum L.) of Neishabur, an experiment carried out in factorial based on Randomized Complete Block Design with three replications in field research of Islamic Azad university of Neishabur during 2012-2013. The factors was humic acid in two levels of application and non application of humic acid, plant density was in three levels of 20, 30 and 40 plants m-2 and supplemental irrigation in three levels of non irrigation, irrigation at flowering stage and irrigation at pod setting stage. In this study seeds were plated by hand. Each plot included five rows with four meters legth, row spacing 25 cm, plant distance on row based on density 20, 13.3 and 10 cm (20, 30 and 40 plants/m2, respectively). 10 plants were selected randomizedly from each plot and pods/plant, seeds/plant, 100-seed weight, plant yield and protein percent were measured. For determining of seed yield, two border rows and 0.5 m from two ends of middle rows were removed and remains were harvested and were put in oven for 48 hours in 70 °C and then were measured. For analysis variance of data software of SAS Ver.9.1.3 were used and treatment mean differences were separated by the least significant difference (LSD) test at the 0.05 probability level.   Results and discussion The effect of humic acid and density on all traits except 100- seed weight and protein percent was significant. All traits were affected by supplemental irrigation. Interaction of acid humic × supplemental irrigation on pods/plant, seeds/plant, plant yield, seed yield and protein yield ha-1 and interaction of density × supplemental irrigation on seeds/plant and plant yield was significant. Consumption of humic acid increased all traits. Seed yield in cosumption and non cosumption of humic acid was 2234 and 1752 kg ha-1, respectively. Increasing of density reduced yield components but seed yield and protein yield ha-1 were increased. Seed and protein yield in density of 40 plants m-2 was 2264 and 521.4 kg ha-1 respevtively. Irrigation increased all traits except protein percent. Seed yield in treatments of irrigation in flowering and pod setting stages was 2417 and 2330 and protein yield was 561 and 531.9 kg ha-1, respectively. In this study, maximum seed and protein yield were obtained by consumption of humic acid and supplemental irrigation at flowering stage with 2697 and 638.2 kg ha-1 that have not differences with cosumption of humic acid and irrigation at pod setting stage with 2648 and 615.3 kg ha-1. Maximum seed and protein yield with 2264 and 521.4 kg ha-1 belonged to treatment of 40 plants m-2.   Conclusion Humic acid and spacially density and supplemental irrigation affected chickpea seed and protein yield. Although by increasing of density yield components were decreased but, seed yield were increased. Irrigation at flowering stage had the highest effect on traits. Non irrigation increased protein percent but, protein yield in this treatment because of lower yield of chickpea was less than other treatments.