芒果白粉病(Oidium mangiferae Berthet)发生流行规律及其综合防治研究

A STUDY OF THE EPIDEMICS OF OIDIUM MANGIFERAE BERTHET AND ITS INTEGRATED MANAGEMENT

芒果白粉病在云南景谷湿热气候芒果种植区 ,对 3年芒果树、象牙芒果树花序、幼果为害率分别为 75.4%～ 91 .6% ,3 2 .1 %～ 54 .3 % ,严重的达 1 0 0 % ,是幼果脱落的主要原因之一 ,损失产量 2 5%～ 3 0 % ,病重树基本绝收。芒果白粉病于2月中、下旬至 5月上、中旬发生为害 ,3月上、中旬至 4月中、下旬为发生高峰期 ,正与芒果盛花期吻合。该病繁殖和侵染最适温度为 1 5℃～ 2 5℃ ,相对湿度为 80 %～ 1 0 0 %。采取综合防治措施 ,特别在盛花期、盛花末与座果交替期各喷药防治 1～2次 ,花序、幼果为害率下降为 5.2 %～ 7.6% ,2 .9%～ 3 .7%。提高了座果率 ,挽回产量 1 5%～ 2 0 %。

An investigation was conducted in mango plantations in Jinggu county of Yunnan province, which is characterized by a tropical rain climate. Oidium mangiferae Berthet, one of the main diseases affecting mango trees, was found to attack the inflorescences and immature fruits of 3 year old mango trees with an infecting rate of 75.4%～91.6% and 32.1%～54.3%, respectively, resulting in severe fruit drop and a yield loss of 25%～30%. This disease occurred from mid and late February to early and mid May, with the peak occurring from early and mid March to mid and late April, which coincided with full bloom of the tree. The optimum temperature for its multiplication and infection ranged from 15℃ to 25℃ and the optimum relative humidity from 80% to 100%. With interated management measures, especially 1 or 2 sprays of pesticide at each of the stages of full bloom, late bloom and fruit setting, reduced infecting rate to 5.2%～7.6% and 2.9%～3.7%, respectively and decreased yield loss by 15%～20%.