近年来中国水稻病虫害发生及趋势分析

水稻是中国重要的粮食作物之一，年种植面积3000万ha，约占粮食作物种植面积的1/3，稻谷产量占粮食总产量的45%。生物灾害是影响中国水稻稳产、高产的重要因素之一。全国每年因水稻病虫害为害虽经防治仍然造成经济损失400-500万t。稻飞虱、稻纵卷叶螟、水稻螟虫、稻瘟病、纹枯病是中国水稻生产上为害严重的几种重要的病虫害，2001-2004年全国水稻病虫害发生面积超过8500kha次，其中2003年稻飞虱、稻纵卷叶螟、水稻螟虫发生面积占总发生面积的72。5%。近年来水稻病虫在全国的发生特点表现为：一、大部地区病虫害发生较重，重大病虫暴发强度大。发生危害严重的病虫有水稻螟虫、稻纵卷叶螟、稻瘟病，发生程度中等以上的有稻飞虱、水稻纹枯病；二、次要病虫上升，为害加重。一些过去偶发性的次要病虫水稻条纹叶枯病、水稻细菌性条斑病、稻曲病等，发生面积扩大，发生程度明显上升，已经或正逐渐上升为重要病虫害；三、发生面积较大，波及面广。2004年以来，西北太平洋副热带高压强度偏强，厄尔尼诺事件将进一步发展，将有利于迁飞性害虫稻飞虱、稻纵卷叶螟的发生为害。近年来，随着粮食种植效益的提高，早稻面积将继续回升，单双季稻混栽面积将进一步加大，对水稻螟虫、稻飞虱、稻纵卷叶螟发生为害有利；部分地区部分高产、优质但易感稻瘟病的水稻品种种植，有利于稻瘟病的发生流行。

Analysis on the Occurrence and Development of Rice Diseases and Insects in China

Rice is one of the important crops in China with annually acreage of 30 million ha, accounting about one-third of whole grain acreage. Rice production is about 45% of total grain production. While, biological disaster is one important barrier to reduce the food quality and yields. It is estimated that losses caused by rice diseases and insect pests arrived 4~5 million tons even after control. Rice plant hopper, rice leaf borer, snout moth insect, rice blast, rice sheath blight are major pests occurred in China. It is estimated that occurrence acreage of rice insects and diseases surpassed 8.5 million ha during 2001-2004, among which, occurrence acreage of rice plant hopper, snout moth insect, rice leaf borer occupied 72.5% of the total acreage of rice insects and diseases. In recent years, occurrence of rice insects and diseases have showed that: rice insects and diseases happened severely in majority of paddy fields, the severest insects and disease include snout moth, leaf borer, and rice blast, rice plant hopper, rice sheath blight disease have occurred in a mid-level scale; Some disease, e.g. rice strip virus, Xanthomonas oryzae pv. oryzicola, Ustilaginoidea oryzae (Patou.) Bref, which did not often occur in many paddy fields, become to be severe problem with gradually increased area, and damage degree; the affected area extended with the enlarged insects and diseases occurrence. Since 2004, north-west pacific high pressure intensity has been stronger, the El Nino event further will further develop, which will be advantageous to migrating insects, rice plant hopper and leaf border. Along with the grain planting benefit enhancement, the early rice area will continue to rise again, planting area of the single double-crop rice will further enlarge. Rice snout moth insect, plant hopper and leaf borer will cause damages advantageously; Rice blast in certain regions on partial high yield and high quality rice varieties is advantageous to occur popularly.