Control. - The treatment is very different in the two cases. If the spore is on the surface of the seed, it may be killed with formalin; but if the seed is infected internally, a different treatment is necessary. The formalin treatment is very simple and inexpensive. Select a clean place on the barn floor, and heap the seed grain upon it. Make a solution of formalin at the rate of 1 pint of formalin to 50 gallons of water. Use as many gallons of this solution as there are bushels of grain to treat. Shovel the grain over, and at the same time spray the formalin over with a sprinkling pot. Shovel over twice, and then cover two hours or over night with blankets or canvas. Spread out the grain to dry. Make allowance for swelling of the seed at the rate of one peck per acre. When the infection is internal, the hot water process of treatment must be resorted to. Obtain a reliable thermometer, and make arrangements to keep a quantity of water at perfectly uniform temperature. Soak the seed in water at ordinary temperature for five to seven hours. Then place it in small loose sacks or wire baskets containing not more than a half peck each, and allow to drain. Provide two tubs or vats, of 30 or 40 gallons capacity, which can be heated, or provide in addition an iron kettle for heating a quantity of water. Heat the water in the two vats to the temperature indicated below. Immerse the drained sacks of seed in tub 1 to remove the chill, then suspend in tub 2 for the indicated length of time. Keep the temperature of tub 2 constant by applying heat or adding small amounts of boiling water. Treat for the indicated time, remove, and dry.
Barley. Covered Smut (Ustilago hordei). — The covering is thin and easily broken, and when old may resemble loose smut.
Control. — Formalin, as indicated above. Loose Smut ( Ustilago nuda). —The smutted heads are loose and black from the first.
Flower infection. Control. — Hot water, as indicated above. The temperature of tub 2 should be 127° F., and the seed should be left in fifteen minutes. If the temperature of tub 2 varies slightly from 127°, the length of treatment should be lengthened or shortened accordingly as the temperature is below or above that desired.
In no case should the temperature go above 129° or below 124° F. This treatment will also be effective for covered smut.
Oats. Loose Smuts ( Ustilago avenae and Ustilago levis). — Both characteristic loose smuts, and both seedling infection. Control. - Formalin treatment, as indicated above.
Stinking Smut or Bunt (Tilletia foetens). - Can be detected in the field by the flaring of the beards, in the bin by the peculiar fetid odor and by breaking open the kernels. The seed coat remains intact.
Seedling infection. Control. - Formalin treatment, as above.
Loose Smut (Ustilago tritici). - Characteristic loose smut of the head appearing at blossoming time.
Flower infection. Control. - Hot water, as indicated above. The temperature of tub 2 should be 129° F., and the seed should be left in ten minutes. If the temperature of tub 2 should go above 129° or fall below 126° the length of treatment should be diminished or increased accordingly. In no case should the temperature go above 131° or below 124°
F. Storage rots (Penicillium expansum and P. italicum). - These two organisms are responsible for much of the rot appearing in storage or transportation. The former is the common one on apples, the latter on oranges and lemons. These organisms are not able to enter through an unbroken surface, but are dependent upon cracks, bruises, scab spots, etc.
Control. — Avoid puncturing the skins with shears or fingernails, handle and pack with care to prevent bruises, and spray to prevent scab spots. Store at a temperature of 32°. In making long distance shipments, pre-cool the car and ship under ice.