Gourd Pests and Diseases

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General Information

Classes of Fungicides: Inorganics are protective (preventative) fungicides

Sulfur: one of oldest fungicides used, about 8 million pounds used in 1990 in U. S.; works as a general growth inhibitor; advantages include cheap cost and ease of application (dusts); disadvantages include limited spectrum of activity (best on mildews), must be applied frequently at a high rate and phytotoxic at high temperatures.

Classes of Fungicides: Sterol inhibitors

Sterol inhibitors: large group of fungicides, widely used, broad spectrum of activity, has both protective and curative activity; include imazalil (Fungaflor), triforine (Funginex), fenarimol (Rubigan), mycobutanil (Nova), propiconazole (Tilt) and triadimefon (Bayleton).

Classes of Fungicides: Fumigants

Highly volatile chemicals that have fungicidal activity; include methyl bromide (controls fungi, nematodes, insects and weeds) and chloropicrin.

Classes of Fungicides: Antibiotics

Antibiotics are substances produced by microorganisms which inhibit growth of plant diseases in very dilute concentrations. Streptomycin (Agri-Mycin): used as dust, spray and seed treatment, mostly for bacterial diseases.

Proper Timing of Application to Spray Nova or Bayleton for Control for Powdery Mildew

For most diseases it takes at least a week from the time the fungus enters the plant until the symptoms appear. In the case of Phomopsis fruit rot, the fungus enters the fruit during bloom and symptoms do not appear until the fruit begins to ripen (harvest). Depending upon the weather, it may take two weeks for black rot symptoms to appear. Once symptoms appear, it is too late to control the disease; therefore, proper timing of the application is critical. The fungus must be controlled before or shortly after it enters the plant.