a f; h a; m k; a a; m m
Abstract
Almost all districts of the country are experiencing quantitative and qualitative decline of agricultural water resources. Considering the extensive expansion of greenhouse cultivation and importance of tomato production, and in order to evaluate the combined effect of salinity and drought stress on ...
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Almost all districts of the country are experiencing quantitative and qualitative decline of agricultural water resources. Considering the extensive expansion of greenhouse cultivation and importance of tomato production, and in order to evaluate the combined effect of salinity and drought stress on growth and yield of tomato plant (Lycopersiconesculentum Mill. Cv. Oriental), four levels of irrigation (125% ETc, 100% ETc, 75% ETc and 50% ETc) and six levels of salinity (0.1, 1.3, 3, 5, 7 and 9 dS/m) were factorially combined in a completely randomized design with 3 replication in a greenhouse soilless culture. Yield and its indexes were measured during the crop growing season. As expected, results indicated that salinity of the nutrient solution and drought stress had significant negative effects on yield and growth indexes of plant. Yield data were fitted on different production functions (simple linear, logarithmic linear, quadratic, and transcendental). The results indicated that the simple linear form was the optimum form. The S1W4 treatment (EC= 0.1 dS/m, and 50% ETc) with 34.6 kg/m3 and S5W1 treatment (EC= 7 dS/m, and 125% ETc) with 6.4 kg/m3 had the highest and lowest water use efficiency, respectively. The iso-yield curves showed that by increasing irrigation water amounts, water with higher salinity can be applied without changing the yield.
a f; h a; m k; a a; m m
Abstract
In order to investigate the economics of simultaneous effect of salinity anddrought stress on growth and yield of tomato plant (LycopersiconesculentumMill.Cv. Oriental), four levels of irrigation (125% ET, 100%ET, 75%ET and 50%ET)and six levels of salinity (0.1, 1.3, 3, 5, 7, and 9 dS/m) were combined ...
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In order to investigate the economics of simultaneous effect of salinity anddrought stress on growth and yield of tomato plant (LycopersiconesculentumMill.Cv. Oriental), four levels of irrigation (125% ET, 100%ET, 75%ET and 50%ET)and six levels of salinity (0.1, 1.3, 3, 5, 7, and 9 dS/m) were combined in afactorial and completely randomized design with 3 replication in a greenhousesoilless culture. Economic model of deficit irrigation optimization was extractedand used for growing tomato in a greenhouse under salinity and drought stresses.The results of this model showed that the net profit of full irrigation of tomato insoilless culture in greenhouse using water of 0.1, 1.3, and 3 dS/m was equal to thenet profit of deficit irrigation at 36%, 21%, and 24%, respectively. Thus,considering the large number of tomato greenhouses with soilless production andvery high price of chemical fertilizers and other costs related to plant nutrition andirrigation, applying approximately 25% deficit irrigation will cause acorresponding reduction in total costs of production, which is economicallysignificant.
Mohammad Kafi; Farzad Hoseinpanahi
Abstract
A field experiment was conducted to evaluate wheat response to low irrigation at the Ferdowsi University of Mashhad, in 2011. Experimental design was split plot with 7 irrigation treatments (main plot), 2 cultivars (sub plot), and 3 replications. Irrigation treatments included full irrigation (FI), without ...
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A field experiment was conducted to evaluate wheat response to low irrigation at the Ferdowsi University of Mashhad, in 2011. Experimental design was split plot with 7 irrigation treatments (main plot), 2 cultivars (sub plot), and 3 replications. Irrigation treatments included full irrigation (FI), without irrigation during spring (NI), irrigation at stem elongation and pollination stages (SP), irrigation at stem elongation and beginning of grain filling stages (SG), irrigation at pollination and beginning of grain filling stages (PG), irrigation at stem elongation, pollination and beginning of grain filling stages (SPG), irrigation at stem elongation, pollination and beginning and middle part of grain filling stages (SPGG). The varieties included Pishgam (drought-resistant) and Gascogne (drought-susceptible). The Results showed that the grain yield of SP، SG، PG، SPG و SPGG treatments decreased by 36%, 40%, 47%, 31%, and 17% compared with the control (FI), whereas their water use decrement were 59%, 58%, 57%, 49%, and 38%, respectively. The drought-resistant cultivar had higher biological and economic yield than the drought-susceptible one, but the biological yield difference between them was more than their economic yield (14% vs. 5%). The highest and the lowest rates of WUE were related to SPGG (1.71) and NI (0.69) treatments. In overall, stem elongation and pollination were the most drought sensitive stages based on this experiment results, therefore, in order to reach high yield under water shortage, irrigation at both of these stages are essential.