Roya Nezamivand Chegini; Mahmood Ghasemnezhad; Mohammad Hassan Biglouei
Abstract
In this study, effect of deficit irrigation from olive fruit set to ripening stage was investigated. Treatments were control (100ETc), the first one regulated deficit irrigation (RDI1); 100% ETc from fruit set to beginning of fruit ripening and 50% ETc after that to harvesting, the second one regulated ...
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In this study, effect of deficit irrigation from olive fruit set to ripening stage was investigated. Treatments were control (100ETc), the first one regulated deficit irrigation (RDI1); 100% ETc from fruit set to beginning of fruit ripening and 50% ETc after that to harvesting, the second one regulated deficit irrigation (RDI2); 100% ETc from fruit set to pit hardening and 50% ETc thereafter to harvest, the third one (RDI3); 100% ETc during fruit set to the pit hardening and the beginning of ripening to harvest and 50% ETc at pit hardening, and no irrigation (rainfed). Fruit and oil yield and oil quality characteristics were evaluated. Results showed that the highest yield of fruit (30.41 kg per tree) and olive oil (5.86 kg in dry weight), the least peroxide value (8.33 meq O2/kg) andK270 (0.164), alsothe highest water use efficiency for fruit and oil production (24.24 and 64.4 kg/m3 , respectively) were in RDI3. The least yield of fruit (8.96 kg per tree) and oil (18.1 kg dry weight) and the highest peroxide value (23 meq O2/kg) was observed in rainfed. Overall, results showed that RDI during fruit pit hardening could increase water use efficiency, whitout reducing fruit yield, quality and oil percentage.
Hamed Ashraf; Hedayat Zakizadeh; Seyed Mohammad Reza Ehtesham; Mohammad Hossein Biglouei
Abstract
In order to evaluate three species of mycorrhizal fungi (Glomus clarum, Glomus fasiculatum and Glomus mosseae) and drought stress (80, 55 and 30 percent of field capacity) on characteristics of grass genera, Lolium perenne, Poa pratensis, Festuca aurandiancea and Agropyron elongatum, a factorial experiment ...
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In order to evaluate three species of mycorrhizal fungi (Glomus clarum, Glomus fasiculatum and Glomus mosseae) and drought stress (80, 55 and 30 percent of field capacity) on characteristics of grass genera, Lolium perenne, Poa pratensis, Festuca aurandiancea and Agropyron elongatum, a factorial experiment based on randomized complete block design was carried out in the greenhouse using a cylindrical pots. According to the results, Lolium showed the highest root colonization with G. mosseae while Poa showed the lowest colonization with G. clarum. Drought stress reduced the root colonization of Festuca and Lolium in all mycorrhizal treatments, but increased the root colonization of Agropyron and Poa with G. clarum and G. fasiculatum. At highest level of stress, G. fasiculatum and G. mosseae increased the chlorophyll and carotenoid contents of grass genera, more than 38 percent. Grasses symbiotic with G. mosseae showed the highest relative water content and lowest electrolyte leakage and malondialdehyde content compared to grasses symbiotic with other species of mycorrhizae. In general, mycorrhizal fungi could reduce the adverse effects of drought stress on grass characteristics, but the tendency to symbiosis and that’s influence on the grass genera under stress, were different.
Kamran Amiri Nasab; Mahmood Ghasemnezhad; Hedayat Zakizadeh; Mohammad Hassan Biglouei
Abstract
Drought preconditioning, which is irrigation with low frequency and longer duration, could be used for extending root system and suppressing drought damage in plants. In the present study, the effect of drought preconditioning for 30 days on increasing tolerance to drought stress in two turfgrass species, ...
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Drought preconditioning, which is irrigation with low frequency and longer duration, could be used for extending root system and suppressing drought damage in plants. In the present study, the effect of drought preconditioning for 30 days on increasing tolerance to drought stress in two turfgrass species, creeping bentgrass (Agrostis stolonifera cv.Palustris) and tall fescue (Festuca arundinacea cv. Greystone) was investigated. Drought preconditioning and control plants were irrigated for 50 days with different levels of soil suction (20-23,40-43, 50-53 and 70-73 centibar), and finally, plants were watered up to field capacity point for 15 days, in order to recovery. The results showed that drought preconditioning increased root to shoot length ratio in both grass species. Preconditioning in both species also showed the higher leaf peroxidase, superoxide dismutase, ascorbat peroxidase and catalase activity than control plants at the end of 50 days of drought stress treatments. At recovery stage, activity of antioxidant enzymes was higher only in preconditioned creeping bent grass compared to control plants. Overall, drought preconditioning could increase drought stress tolerance in both turfgrass species by increasing root to shoot ratio and improving enzymatic antioxidant systems.
