PHYSIOLOGICAL RESPONSE OF SESAME TO SOIL MOISTURE STRESS AND POTASSIUM FERTILIZATION IN SANDY SOIL. | ||||
| Fayoum Journal of Agricultural Research and Development | ||||
| Article 8, Volume 23, Issue 1, January 2009, Page 88-111 PDF (553.34 K) | ||||
| Document Type: Research articles. | ||||
| DOI: 10.21608/fjard.2009.197017 | ||||
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| Authors | ||||
| Fatma A. Abdo; N. A. Anton | ||||
| Crop physiology Res. Dep., Field Crops Res. Institi., A.R.C., Egypt. | ||||
| Abstract | ||||
| A field trail was conducted at Ismailia Agricultural Research Station during the two successive seasons 2006 and 2007 to study the physiological response of sesame cv. "Shandaweel-3" to three levels of available soil moisture depletion (ASMD) namly wet (20-25%), medium (45-50%) and dry (65-70%) as well as potassium fertilization at the rates of 0, 24, 48 kg K2O/fed and spraying 1% K2O alone or in combination with added 24 kg K2O/fed. Results of combined analysis could be summarized as follows: - Increasing soil moisture stress up to 65-70% ASMD significantly decreased plant height, fruiting zone length, leaf area index (LAI) at 56, 70 and 84 days after sowing (DAS), relative growth rate (RGR), net assimilation rate (NAR) at 56-70 and 70-84 DAS, total chlorophyll, carotenoides contents of leaves and chlorophyll fluorescence. Whereas, proline content in leaves was significantly increased. Dry treatment significantly reduced 1000-seed weight, number of capsules, capsules, straw and seed weights/plant, straw and seed yields/fed as well as total carbohydrates and oil contents in seeds. Exposing sesame plants to severe water deficit decreased relative water content of leaves (RWC), seasonal water consumptive use (WCU), water use efficiency (WUE) and transpiration rate (TR), while stomatal resistance (SR) was increased. The maximum value of WUE was obtained when plants received medium treatment compared with wet or dry treatments. - Applying 24 kg K2O/fed in combination with spraying 1% K2O significantly increased plant height, fruiting zone length, LAI at 56, 70 and 84 DAS, RGR at 56-70 and 70-84 DAS, NAR at 56-70 DAS, total chlorophyll, carotenoides contents of leaves, chlorophyll fluorescence, 1000-seed weight, number of capsules, capsules and seed weights/plant, straw and seed yields/fed. While, straw weight/plant was significantly increased when plants received 48 kg K2O/fed. Proline content of leaves and SR significantly increased without adding potassium fertilizer. The maximum value of total carbohydrates and oil contents in seeds, RWC, TR, WCU and WUE recorded the highest values when plants were treated with 24 kg K2O / fed and sprayed by 1% K2O. - The interaction effect between water stress and potassium fertilization was found to be significant on LAI at 56 DAS, carotenoides content of leaves at 70 and 84 DAS, chlorophyll fluorescence, leaf proline content, number of capsules/plant, capsules, seed and straw weights/plant, total carbohydrates and oil contents in seeds, RWC at 70 and 84 DAS, SR and TR. The maximum value of WUE was obtained when plants were irrigated at 45-50% ASMD and received 24 kg K2O / fed with spraying 1% K2O. | ||||
| Keywords | ||||
| Sesame; Water stress; Potassium fertilization; Sandy soil | ||||
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