苜蓿褐斑病在新疆的发生

OCCURRENCE OF COMMON LEAFSPOT OF ALFALFA IN XINJIANG

采用重点调查和定点定期系统调查的方法对新疆苜蓿褐斑病的发生及危害进行了研究。结果表明，苜蓿褐斑病在北疆严重发生或中度发生，在南疆地区轻度发生。春季返青和各茬苜蓿刈割后１７～２２ｄ，田间陆续开始发病。夏、秋季发病较重，发病盛期从７月中旬到９月下旬。重病田提前刈割可有效地延缓病情的发展，降低产量损失。

Using the method of major investigation and location and regular systematical investigation, the occurrence and harm of alfalfa leafspot in Xinjiang were investigated. The result showed that the common leafspot occurred seriously or mediately in northern Xinjiang, and lightly in southern Xinjiang. The disease appeared in spring reviving and 17～22 days after cutting, and serious in summer and autumn. The severe period was from mid-July to last-September. Pre-cutting in the heavily infected field could delay the disease development and decrease yield loss.