نوع مقاله : مقاله پژوهشی
نویسندگان
1 مربی پژوهشی مرکز تحقیقات کشاورزی و منابع طبیعی استان مازندران
2 مربی پژوهشی مرکز تحقیقات کشاورزی و منابع طبیعی استان فارس
3 استاد گروه خاکشناسی دانشگاه تربیت مدرس
چکیده
کلیدواژه‌ها
عنوان مقاله [English]
نویسندگان [English]
Considering the fact that drought is frequently one of the limiting factors in crop production in dry regions, suitable solutions in overcoming drought is of major importance. For this purpose, an evaluation was made of the effect of potassium sulfate on improving the drought resistance of Chamran wheat variety (Triticum aestivum L.). The experiment was carried out in a completely randomized split plot design in three replications for three growing seasons (1999-02) at Darab Agr. Res. Center. The main factor consisted of four levels of irrigation extracted from the book on water requirement: 1. (the control); 2. Twenty percent less water than used for the control (as a moderate drought stress); 3. Frothy percent less water than used for the control (as medium level drought stress); and 4. Sixty percent less water than used for the control (as a severe drought stress), and the subfactor consisted of three levels of potassium, namely, 0, 100 and 200 kg K2O/ha as potassium sulfate. The three year research showed that the yield decreased under drought conditions. While the yield for the control treatment was measured at 5821 kg/ha, it was reduced to 5404, 3927 and 1967 kg/ha for moderate, medium and severe drought conditions, respectively. However, the rate of yield losses was reduced as a result of the application of potassium sulfate. In other words, with the application of potassium sulfate, yield losses were moderated even under severe drought conditions. The results also showed that the losses in grain yield were negligible as compared with the control even with a 20% reduction in water consumption. However, by decreasing the water consumption levels by 40% and 60%, instead of 20% severe drops in grain yields were observed. The application of 100 and 200 kg K2O/ha of potassium sulfate significantly lowered the grain yields by 9.5 and 16.3%, respectively, as compared with the control. The increases in grain yield seen with potassium applications were caused by the increases in the yield components. It was concluded as a whole that with the application of 200 kg K2O/ha, the level of drought resistance as well as the grain yield improved under drought conditions; the negative effects of moisture deficiency on the losses of grain yields were also moderated to some extent. Therefore, potassium application under various levels of drought stress can offer a practical solution for improving drought resistance as well as preventing yield losses in wheat.
کلیدواژه‌ها [English]
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