Evening Republican, Volume 18, Number 67, Rensselaer, Jasper County, 19 March 1914 — SMUT OF OATS AND ITS PREVENTION [ARTICLE+ILLUSTRATION]

SMUT OF OATS AND ITS PREVENTION

By C. A. Ludwig,

Botanical Depart-

ment, Purdue University Experiment Station. Purdue University Agricultural Extension.

In some localities there is a saying among farmers that when there are a good many of the black “blasted” heads in a field of oats, it is a sign of a good crop. ‘As a matter of fact, it is a sign that each head so affected is destroyed, and the crop decreased by just so much. The cause of the destruction of these heads is the loose sjr.’-Jt fungus of oats. This fungus, as shown by the reports of the plant disease correspondents of the Botanical Department (for the last six or seven years), has a very general distribution over the state, and causes damage in the different counties of an estimated severity varying from practically nothing to 10 or 12 per cent. Where this more severe injury oc-

curs, it is enough in most cases to take away all the profit from the crop. The disease is easily prevented, however, so that any injury greater than an altogether negligible amount (much less than one per cent) is hardly excusable on a well managed farm. This statement is rendered the more emphatically true by the fact that the treatment to be discussed destroys seed-borne spores of other harmful fungi and seems to stimulate the young' seedling, so that it would be a paying proposition in most cases even though there were no smut present. Life History. The point of weakness in the fungus is its method of infecting the

plant. The black masses, which at harvest time take the place of the ripened grains of oats, are made up of the spores. In the operations of cutting, hauling, threshing, etc., these spores are shaken- off and scattered in great numbers in the straw, chaff and grain. Many of them lodge on the threshed grains. When these grains are planted, the spores germinate along with the oats. The fungus grows into the young seedling, and grows upward with it, entering all the tillers, or stooling shoots. When blossoming and fruiting time comes, the parasite enters the heads and destroys them, so that instead of plump heavy grains, only a number of black masses of dusty spores results. The cut shows in good shape the appearance of such heads, and also the appearance of a normally developed one. The Remedy. The remedy for this disease, which was worked out at this station about 15 years ago, is simple and effective. It takes advantage of the one exposed place in the life history of the parasite which, as has already been mentioned, is the spore stage. The spores which do the infecting 'are those lodged on the outside of the grains at planting time. The method adopted is to kill the spores before the seed is sowed. The procedure is as follows: Sprinkle the seed with a solution of one pint of (40 per cent) formaldehyde solution to 60 gallons of water until thoroughly moist, shoveling over repeatedly to distribute the moisture evenly. Shovel into a pile and cover with sacks or canvas for at least two hours. It will be all right to leave it longer, even over night, but it should not be left long enough to start germination. After this treatment, spread the grain out to dry. Drying may be hastened by spreading in a thin layer and stirring occasionally with a rake. When dry enough, the seed may either be sown immediately or be stored until later. Care should be taken not to allow the treated seed to come in contact with sacks, bins or drills which are carrying the spores, or it will be freshly infected. The formaldehyde is not dangerous to use, as it is only a mild poison even when concentrated. In the dilute form inWhich it is used, it is practically harmless. The ofily disagreeable feature about it is that the strong solution and the vapor from it are irritating to the nose and eyes in much the same way and to about the same extent as with strong ammonia. With this simple procedure it 'is easy to treat seed oats for smut; and if the work be carefully done, it insures a crop free of the disease.