Powdery Mildew
Powdery mildew is a foliar disease at early stages and is very similar to downy mildew. Plants affected at early stages fail to develop full-grown fruits.
The causal pathogen is Phodosphaera xanthii, the colonies appear on the upper and lower surface of the leaves. Development is favored by high humidity and temperature.
What are the symptoms
Typical symptoms appear as white powdery mold primarily on the upper leaf surface. On the lower leaf surface, symptoms occur as circular patches or spots and first occur on older leaves. Severely affected foliage becomes brown and shriveled, and defoliation may occur.
Impact to the crop
Fruits of the affected plants do not develop fully and remain small which directly affects the quality and quantity of yield.
How to control
Use of resistant varieties, plant in an area with high light intensity and with good air circulation, Avoid excessive use of N fertilizer or use od slow-release fertilizer, removal of weeds and other possible alternate hosts, application of protectant fungicides such as benomyl and azoxystrobin for susceptible varieties
Source: Dela Cueva, FM, CB Pascual, CM Bajet and TU Dalisay. 2015. Pests and diseases of economically important crops in the Philippines.Pest Management Council of the Philippines, Inc. c/o Crop Protection Cluster, University of the Philippines Los Banos, College, Laguna
