Smut is a parasitic fungus, and springs from a spore (which corresponds to a seed in higher plants). This germinates when the grain is seeded and, penetrating the little grain plant when but a few days old, grows up within the grain stem. After entering the stem there is no evidence of its presence until the grain begins to head. At this time the smut plant robs the developing kernels of their nourishment and ripens a mass of smut spores.

These spores usually ripen before the grain, and are blown about the field, many spores becoming lodged on the ripening grain kernels. The wholesale agent of infection is the threshing machine. For this reason the safest plan is to treat all seed wheat and oats each year.

Secure a 40 per cent solution of formalin (the commercial name for formaldehyde gas held in a water solution). About 1 ounce is required for every 5 bushels of grain to be treated.

Clean off a space on the barn floor or sweep a clean space on the hard level ground and lay a good-sized canvas down, on which to spread out the wheat. See that the place where the grain is to be treated is swept clean and thoroughly sprinkled with the formalin solution before placing the seed grain there.

Prepare the formalin solution immediately before use, as it is volatile, and if kept may disappear by evaporation.

Use 4 ounces of formalin for 10 gallons of water. This is sufficient for 600 pounds of grain. Put the solution in a barrel or tub, thoroughly mixing.

The solution can be applied with the garden sprinkler. Care must be taken to moisten the grain thoroughly. Sprinkle, stir the grain up thoroughly and sprinkle again, until every kernel is wet.

After sprinkling, place the grain in a conical pile and cover with horse-blankets, gunny sacks, etc. The smut that does the damage lies just under the glume of the oats or on the basal hairs of the wheat. Covering the treated grain holds the gas from the formalin within the pile, where it comes in contact with the kernels, killing such smut spores as may have survived the previous treatment. After the grain has remained in a covered pile 2 to 4 hours, spread it out again where the wind can blow over it, to air and dry.

As soon as the grain can be taken in the hand without the kernels sticking together, it can be sown in the field. The grain may be treated in the forenoon and seeded in the afternoon.

Since this treatment swells the kernels it hastens germination and should be done in the spring just before seeding time.

While the copper sulphate or blue-stone treatment is valuable in killing smut, the formalin treatment can be given in less time, is applied so easily and is so effectual that it is recommended as a sure and ready means of killing smut in wheat and oats.