Kankakee Valley Post, Volume 9, Number 50, DeMotte, Jasper County, 2 November 1939 — FARM TOPICS [ARTICLE]

FARM TOPICS

PLANT DISEASE EASILY SPREAD Insects Are Found to Be Chief Carrier Agents.

By C. W. HUNGERFORD

How are plant diseases spread? There is little mystery in the answer to that question, though plant scientists, entorffologists, and others are constantly adding to our knowledge of the subject. Man, domestic animals, rodents, slugs, snails, birds, insects, wind and water are among the more common agencies that spread plant diseases. Insects are the most important spreaders of certain types of diseases, according to the results of tests conducted at the Idaho college of agriculture. Perhaps you have wondered just what causes plant diseases. Plant diseases have about the same causes as diseases of animals and humans. Fungi and bacteria cause many plant diseases. Others are caused by> a group of organisms known as viruses, which are too small to be detected with the most powerful microscope. Wind and rain act as agencies for spreading many plant diseases. In some of the winter wheat growing areas of the country the spores of the stinking ant are blown in such quantities that “smut showers” occur and many thousands of spores fall on every square foot of ground. Birds may also carry fungus spores. In one case a single downy woodpecker was found to be carrying over 750,000 spores of the chestnut blight fungus. The secret of control for many virus diseases lies in the control of insects, which are the principal means of spreading these diseases in the field. Much can be done to prevent the spread.of plant diseases in general by seed treatment and by general sanitary practices around the farm. Burning of diseased plants and disinfection of pruning tools and various containers are examples of proper sanitary practices.