小麦叶锈病是河南省小麦的重要病害之一.2009～2010年对河南省南阳市小麦叶锈病发生进行了系统调查.2009年病害始发于4月8日,此时田间病叶率为0.56%;4月22日～29日病害进入快速增长期,仅7d病叶率由4.11%速增至34.11%,病情指数由0.51攀升至6.57.5月6日病叶率和病情指数分别达78.78%和29.95,之后增速逐步减缓.2009年病情消长表现出＂S＂型曲线特征.2010年叶锈病的初发期与2009年相比约推迟了一个月,且病情显著减轻.通过对气象因子进行比较,推测2月～4月份的平均气温异常偏高是造成2009年南阳市小麦叶锈病严重发生的主要原因之一.%Wheat leaf rust is an important disease in wheat production in Henan provinve,China.The occurrence of the disease was systematically investigated during 2009 to 2010 in Nanyang city,Henan province.The disease was initially observed on Apr 8,2009,with a leaf disease incidence of 0.56%,and slowly developed before Apr 22.Rapid disease development occurred from Apr 22 to 29,in which the leaf disease incidence sharply rosed from 4.11% to 34.11%,and disease index from 0.51 to 6.67 only within 7 days.On May 6,the leaf disease incidence and disease index reached to 78.78% and 29.95,respectively,and their incremental rates subsequently stepped down.The increasing patterns of both leaf disease incidence and disease index exhibited the characteristics of an S-type curve.As compared to 2009,the occurrence of the disease was delayed for approximately one month in 2010,with markedly reduced leaf disease incidence and disease index during the growing seasons.Based on a comparison of climatic factors,the daily average temperatures for a month during Feb to Apr in 2009 were found to be much higher than normal years,which was speculated to be the main reason for the severe occurrence of wheat leaf rust in 2009 in Nanyang.
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