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Simulation of simultaneous effect of salinity and drought stresses on grain yield of rice cv. Hashemi
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Abstract: (4422 Views) |
| Simultaneous effect of salinity and drought stresses and their critical limits imposed on cv. Hashemi (most common rice cultivar in Guilan province) was investigated. Also the best model to estimate the reduction of plant's water absorption due to simultaneous interaction of salinity and water stresses was identified. Experimental treatments consisted of three levels of irrigation continuous flood irrigation (3 cm water height) and two intermittent irrigation (4 and 8 days intervals) and five levels of salinity by using irrigation water with electric conductivity of 1, 2, 3, 4 and 5 dS.m-1applied in factorial based randomized block design with four replications. Results indicated that for rice plant yield loss threshold due to drought stress occurred at soil moisture about 80% of saturation. Salinity threshold for this cultivar was at soil extraction of 2.83 dS.m-1 which implies it’s sensitivity to salinity. Among the evaluated models, the best model for predicting the reduction of plant's water absorption due to simultaneous effect of salinity and water stresses is Homaee and Feddes for rice. In this model, by subtraction of yield reduction threshold osmotic pressure from the soil water pressure in permanent wilting point, simultaneous effect of salinity and water stresses assumed to be less than total or product of these stresses. It is concluded that under conditions when drought and salinity stresses are not balance, predictions by this model are closer to observation and the prediction of relative low grain yield is possible. |
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| Keywords: Drought stress, Salinity stress, Rice and Water uptake models |
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Full-Text [PDF 381 kb]
(2420 Downloads)
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Type of Study: Scientific & Research |
Subject:
Special
Received: 2015/02/15 | Accepted: 2015/02/15 | Published: 2015/02/15
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