Physiological Response of Alhagi pseudoalhagi to Root Exhausting Management During Fallow Season

بمنظور ارزيابي توان جوانه زني بالقوه ريشه هاي ريزومي قطع شده خارشتر به عنوان شاخصي از امكان رشد مجدد آن پس از اعمال مديريت مكانيكي، آزمايش هاي متعددي در مركز تحقيقات كشاورزي و منابع طبيعي خراسان رضوي طي سال هاي 85-1384 به اجرا درآمد. مقاطع ميكروسكپي ريشه تهيه گرديد تا ماهيت ريزومي آن مشخص گردد. اثرات قطع ريشه در مزرعه مورد آزمون قرار گرفت. بدين منظور در يك مزرعه كاملا پوشيده از خارشتر، سه عمق 10، 20 و 30 سانتيمتري شخم در طي فصل آيش اعمال گرديد. 20، 30 و 50 روز بعد از اعمال تيمارها تعداد ريشه هاي قطع شده اي كه مجددا جوانه زده بودند ثبت گرديد. توان رويش مجدد بخش پاييني ريشه هاي تيمار شده در عمق خاك نيز مورد بررسي قرار گرفت. بدين منظور ريشه خارشتر از 4 عمق 0، 10، 20 و 30 سانتيمتري از سطح خاك در يك مزرعه با توزيع طبيعي گياه قطع گرديد. تاريخ جوانه زني، ارتفاع گياه، سطح سايه انداز كانوپي، تعداد شاخه ها و ماده خشك در رويش هاي مجدد 7، 10، 17، 24، 34، 41 و 58 روز پس از اعمال تيمار ها يادداشت گرديدند. شاخص هاي رشد ازجمله سرعت رشد گياه و سرعت جوانه زني نيز محاسبه گرديدند. نتايج نشان دادند كه تفاوت معني داري در توان جوانه زني ريشه ها با طول قطع متفاوت در مزرعه وجود دارد..در عين حال هيچ يك از ريزوم هاي كاشت شده در گلدان ها قادر به جوانه زني نبودند. عمق قطع تاثير معني داري بر ويژگي هاي رشد اين گياه داشت. ارتفاع نهايي، سطح سايه اندازو وزن خشك تك بوته توسط افزايش عمق به شدت كاهش يافتند. مي توان نتيجه گرفت كه با افزايش عمق قطع تا 30 سانتيمتر امكان مديريت موفق تر خارشتر وجود خواهد داشت.

A series of experiments were conducted in Khorasan Agricultural and Natural Resources Research Center (Mashhad, Iran) to evaluate potential germination ability of detached rhizomatous roots as an index of recovery after mechanical management during 2005-2006. Microscopic cross sections were prepared to study the rhizomatous nature of the roots. Effects of the in situ root detaching were examined. Three depths of plough i.e. 10, 20 and 30cm were applied at a field highly infected with camelthorn (Alhagi pseudoalhagi) during fallow season. Samples were taken to record the number of germinated detached roots 20, 30 and 50 days after treatment. To quantify revival of mechanically treated rhizomes undetached from root bases, further experiments were performed during the fallow season of 2005. Camelthorn was cut off from 4 different soil depth i.e. 0, 10, 20 and 30 cm at an infected field with natural distribution. Date of germination, plant height, canopy shading area, number of shoots and dry matter were recorded at 7, 10,17, 24, 34, 41 and 58 days after treatment (DAT). Various physiological indices including plant growth rate and germination rate were determined. The results revealed that roots with various length of detachment at the field differ significantly in ability to recover. However, no germination in all pot experiments was recorded. Soil depth for cutting off roots could make significant differences on plant growth characteristics. Final shoot height was significantly reduced by depth of cutting. Almost the same pattern was recorded in case of canopy shading area and single plant dry matter. In conclusion, the deeper plow depth the more suppressed plants are, and as a consequence, we have better camelthorn management.