番茄叶霉病的发生与防治研究

Study on Occurrence and Control of Tomato Leaf Mould

调查研究表明：番前叶霉病在西安地区春季覆盖大棚和大棚秋延栽培中出现春秋２个发病高峰，以春季发病危害严重。在保护地适温高湿下，从发病始期至盛期，只需１０～１５ｄ，病叶率可达３０％～９０％，产量损失１０％～２５％。当地栽培的番前品种对叶霉病均无抗性。番茄叶霉病发病程度主要与棚内外湿度密切相关，薄膜类型、浇水方式、二次覆盖等对病害的发生均有影响。Ｃｌａｄｏｓｐｏｒｉｕｍｆｕｌｖｕｍｃｏｏｋｅ在ＰＳＡ培养基上２０～２７℃时，菌落发育良好，高于３０℃时，菌落停止生长。在饱和湿度下，２３℃时，分生饱子４ｈ后萌发。用分生饱子悬浮液接种幼苗，叶片湿润时间越长，发病率越高。定植前采用硫磺粉熏棚，发病初期喷洒７０％甲基托布津ＷＰ、波尔多液，对番茄叶霉病均有良好的控制效果。

The study indicated that tomato leaf mould occurred in plastic protecied field inXiian area with two peaks i. e ,one peak was in spring ;another was in autumn. The occurrence inspring was more serious. Under the condition of high humidity and proper temperature ,only 10-15 days were needed for the disease to develop from initial stage to prevailing stage. The diseaseincidence on leaf could reach 30%～90% which cause yield losses by 10%～25%.No resistant varieties. to the disease have been found among local commerial varieties.Due to the close correlation between humidity and field disease incidence ,the disease severitycould be affected by the following factors, type of plastic film, way of irrigation and using ofgroundcovering plastic film.The fungus , Cladosporium futvum cooke,grows well on PSA medium at the temperature of20～30℃. Whereas 'the fungus colony cease to develop at the temperature higher than 30℃.Spores germinate 4 hours later under saturated humidity and at the temperature of 23℃.When tomato seedlings were sprayed with spore suspension,the longer the leaves were mois-turized ,the more serious the disease incidence were.Those methods such as : fumigating the plastic tunnel with sulphur before transplantig ,spray-ing Topsin-M 70% WP or Bordeaux mixture at the initial stage of the disease development gavegood control of the disease.