江苏省小麦纹枯病发生规律与病害消长因素分析

STUDY ON OCCURENCE OF WHEAT SHARP EYESPOT IN JIANGSU AND THE FACTORS INFLUENCING ITS DEVELOPMENT IN FIELDS

研究结果表明,小麦纹枯病田间发生规律大体有冬前发生期、越冬稳定期、返青上升期、拔节盛发期和抽穗后枯白穗显症期五个阶段。小麦越冬前和早春拔节期有2个发病高峰,小麦根围土中病原菌群体数量消长也出现相应的2个高峰,病菌数量高峰较小麦发病高峰约提前20—25天。秋冬降雨量的多少是影响冬前病害发生的主导因子,影响春季病害发生程度的重要气象因素是温度。相关性测定表明,温度与病害发生程度呈显著正相关。因地制宜适期精量播种、平衡施肥和冬前防除麦田杂草等栽培技术,均能有效地控制和减轻小麦纹枯病的发生与为害。

This study indicated that the occurence of wheat sharp eyespot in the field can be divided into five periods,i. e. disease appearing period before winter,stabling period during winter,spreading period at the begining of wheat growth in spring, outbreak period at wheat jointing stage and withered ears appearing period after heading. There are two peaks of the disease occurence before winter and at early spring, in relation to which, two peaks of the amount of Rhizoctunia spp. in the rhizosphere also appear, but earlier than disease peaks for about 20 - 25 days. The amount of precipitation before winter is the main factor influencing disease occurence in wheat planting area. The higher moisture (due to higher precipitation), the more serious disease. The most important factor influencing the disease development in spring is temperature which significantly correlates to the disease severity. It also explored that cultural practices are the factors influencing disease development and , therefore, the disease can be effectively controlled in the spring by properly delaying of sowing time, rationally applying of fertilizer to avoid excess nitrogen, reasonable seed quantity, and well weeding before winter.