Occurrence of Powdery Mildew of Autumn Delayed Tomato Cultivated in Facilities Soilless Matrix and Test of Its Pesticide Control

【Objective】The aim of this paper was mainly to investigate the occurrence and spread of Powdery mildew from autumn delayed tomato under the conditions of facilities soilless matrix cultivation and the control effects ot 7 chemical pesticides on Powdery mildew were surveyed to screen the low toxicity and high efficient pesticides.【Method】The classification and investigation of the diseases were made by 5 sample points.comparaed control effect difference of different pesticide on tomato powdery mildew by field plot test.【Result】Autumn delay tomato powdery mildew occurred on September 28,reached the peak on November 20.Tomato powdery mildew occurrenced and spreaded when the average temperature of greenhouse aroud 13 ℃,humidity 75% in early November.The early stages of tomato powdery mildew,7 fungicides were effective against more than 99%.Early onset,control effect of 40% Myclobutanil was 86.36%,the best control effect.【Conclusion】Tomato powdery mildew was horizontal and vertical expansion in the field,Tomato disease of autumn delay stubbles began to appear in September late,was the optimum pesticide time.and Myclobutanil was the best choice,Flusilazole,Azoxystrobin and Diniconazole can be used as the rotationally applied bactericide.