عنوان مقاله [English]
Dust storms over Middle East are one of the most important environmental and pollution problems. In order to assess the effects of dust deposition and supplemental irrigation on yield and yield components of chickpea, an experiment was conducted at the research farm of Agriculture and Natural Resources Campus of Razi University, Kermanshah, in 2013-2014 growing season based on RCDB with three replicatins. Treatments of the experiment included supplemental irrigation as the main plot factor with 2 levels (No-irrigation and irrigation at poding stage). and dust deposition as the sub plot factor with7 levels (Control, dust application at vegetative stage, dust application at poding stage, dust application at pod filling stage, Washing at the end of vegetative stage, Washing at the end of poding stage and Washing at the end of vegetative and poding stages).Supplemental irrigation and dust deposition had significant effect on yield and yield components of chickpea. Drought stress reduced yield and yield components. With dust application at vegetative stage (67.86 g.m-2), poding stage (79.37 g.m-2) and pod filling (79.52 g.m-2) seed yield reduced. With Washing leaves at the end of vegetative and poding stages seed yield (85.20 g.m-2) increased.
Materials and Methods
This study was conducted during 2013-2014 at the research Farm of Razi university in Kermanshah state in the west of Iran (47º 9′ E and 34º 21′ N), 1319 meters above sea level. The soil of the research area was clay loam (36.1% clay, 30.7% silt) and was cultivated with chickpea previously. Treatments included supplemental irrigation as the main plot at 2 levels (control (non-irrigation) and irrigation at poding stage. Other treatments included dust deposition as the sub plot at 7 levels (Control (non-treatment, dust application at vegetative stage, dust application at poding stage, dust application at pod filling stage, Washing at the end of vegetative stage, Washing at the end of poding stage and Washing at the end of vegetative and poding stages). Experiment was a randomized complete block design with three replications. The Analysis of variance using SAS softwares was performed for studied parameters. The means were compared using Duncan test at level of 0.05 probabilities.
Results and Discussion
Dust particles deposited on chickpea leaves resulted in the reduction of the total dry matter and seed yield. Interaction of supplemental irrigation and dust deposition on biological yield, seed yield, harvest index, number of seeds per plant, number of pods per plant and number of lateral branches were significant. The highest biological and seed yield were obtained due to the interaction of Supplemental irrigation and Control (no dust deposition) with 341 and 144 g.m-2, respectively. Zia-Khan et al., (2015) reported the mean reduction of yield in the dusted treatment was about 28%, indicating that the stress conditions in this experiment were relatively severe. Chaurasi et al (2013) reported a decrease in dry matter of groundnut planted in the vicinity of a cement factory, and an increasing rate of groundnut dry matter accumulation was observed while the distance of farm and factory increased.. By cleaning the dust particles of the leaves at the end of growth and poding stages, carbon assimilation and finally grain yield slightly increased. This findings are also according to Zia-khan et al., 2014. Chouhan & Joshi (2010) reported that the growth of wheat at 0.5km distance from a Cement industry was lesser than to plants farther from the cement industry. Armbrust, (1986) Reported a decrease in dry matter accumulation after three days of dust application.
According to the results of this experiment, the drought stress and the dust deposition on leaf surfaces, cause a reduction in light absorption of leaves, reduction stomata conductance, photosynthesis and transpiration and increase leaf temperature. The results of this study show that yield and yield components of chickpea adversely affected by dust deposition at different growth stages. Future researches should focus on the effect of dust deposition on other crops like wheat and the ability of crops to capture the dust deposition in different climatic regions.