Diseases of wheat

Wheat is subject to more diseases than other grains, and, in some seasons, especially in wet ones, heavier losses are sustained from those diseases than are felt in the culture of any other culmiferous crop with which we are acquainted. Wheat may suffer from the attack of insects at the root; from blight, which primarily affects the leaf or straw, and ultimately deprives the grain of sufficient nourishment; from mildew on the ear, which operates thereon with the force of an apoplectic stroke; and from gum of different shades, which lodges on the chaff or cups in which the grain is deposited.


Blight originates from moist or foggy weather and from hoar-frost, the effects of which, when expelled by a hot sun, are first discernible on the straw, and afterwards on the ear, in a greater or less degree, according to local circumstances. Let a field be examined in a day or two after such weather, and a careful observer will soon be satisfied that the fibres and leaves of plants are contracted and enfeebled, in consequence of what may be called a stoppage of perspiration. This disorder may take place either earlier or later, but is most fatal when it appears at the time the grain is forming in the ear. It may appear at an earlier stage; and though the productive powers of the plant will thereby be lessened, yet, if circumstances are afterwards favorable, the quality of the grain produced may not be much impaired; or it may appear after the grain is fully formed, and then very little damage will be sustained, except by the straw.


Mildew may be ranked as a disease which affects the ear, and is brought on by causes somewhat similar to those which occasion blight, though at a more advanced period of the season. If this disorder comes on immediately after the first appearance of the ear the straw will also be affected, but if the grain is nearly or fully formed then injury on the straw is not much discernible. We have seen a crop that carried wheat that was mildewed where the straw was perfectly fresh, though, indeed, this rarely happens. A severe mildew, however, effectually prevents both grain and straw from making any further progress, the whole plant apparently going backward every day till existence in a manner ceases altogether. Something akin to mildew is the gum, which, in all warm moist seasons, attaches itself to the ear, and often occasions considerable damage. All these different disorders are generally accompanied by insects, and by minute parasitic vegetable growths, considered by many to be the authors of the mischief that follows. Their appearance, however, may justly be attributed to the diseased state of the plant; for wherever putrefaction takes place, either in animal or vegetable substances, the presence of these parasites will never be wanting.

Another disorder which affects wheat and is by several people denominated the real rust, is brought on by excessive heat, which occasions the plants to suffer from a privation of nourishment, and become sickly and feeble. In this atrophic state a kind of dust gathers on the stalks and leaves, which increases with the disease, till the plant is in a great measure worn out and exhausted. The only remedy in this case, and it is one that cannot easily be administered by the hand of man, is a plentiful supply of moisture, by which, if it is received before consumption is too far advanced, the crop is benefited in a degree proportional to the extent of nourishment received, and the stage at which the disease has arrived.

Some people have recommended the sowing of blighted and mildewed wheat, because it will vegetate; though certainly the recommendation, if carried into practice, would be attended with imminent danger to those who attempted it. That light or defective wheat will vegetate and produce a plant we are not disposed to contradict, but that it will vegetate as briskly, or put out a stem of equal strength, and capable of withstanding the severe winter blasts as those produced from sound seed we must be excused for not believing. Let it only be considered that a plant of young wheat, unless when very early sown, lives three or four months, in a great measure, upon the nourishment which it derives from the parent seed; and that such nourishment can, in no view of the subject, be so great when the parent is lean and emaciated as when sound, healthy and vigorous. Let it also be remembered that a plant produced from the best and weightiest seed must, in every case, under a parity of other circumstances, have a stronger constitution at the outset, which necessarily qualifies it to push on with greater energy then the season of growth arrives. Indeed, the economy of nature would be overturned should any other result follow. A breeder of cattle or sheep would not act more foolishly, who trusted that a deformed diminutive bull or ram would produce him good stock, than the corn farmer does who uses unsound or imperfect seed.


A solution of common salt in water, in the proportion of a pound to a gallon, is an excellent remedy for the mildew on grain. After sprinkling three or four days, the mildew will dissapear, leaving only a discoloration on the straw where it was destroyed. The best and most expeditious way of applying the mixture is with a flat brush such as is used by whitewashers. The operator having a pail of the mixture in one hand, with the other he dips the brush into it, and makes his regular casts as when sowing grain broadcast; in this way he will readily get over ten acres in the day, and with an assistant a great deal more. About two hogsheads of the mixture will suffice for an acre. Wherever the mixture touches the mildew immediately dies.


Dissolve three ounces and two drachms of sulphate of copper, copperas, or blue vitriol, in three gallons and three quarts, wine measure, of cold water, for every three bushels of grain that is to be prepared. Into another vessel capable of containing from fifty-three to seventy-nine wine gallons, throw from three to four bushels of wheat, into which the prepared liquid is poured until it rises five or six inches above the grain. Stir it thoroughly, and carefully remove all that swims on the surface. After it has remained half an hour in the preparation, throw the wheat into a basket that will allow the water to escape, but not the grain. It ought then to be immediately washed in rain, or pure water, which will prevent any risk of its injuring the germ, and afterwards the seed ought to be dried before it is sown. It may be preserved in this shape for months. Another method, which has been tried in Russia, is to espose the seed for one or two weeks to a dry heat of about 80 or 90.

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