3. Hand pick the worms from the plants after they are set out, for the first one or two hoeings, or until the worms become very numerous.
4. Spray with kerosene emulsion, made by using two gallons of kerosene, one-half pound of common or whale oil soap, and one gallon of water. Dissolve the soap in the water, and add it, boiling hot, to the kerosene; then churn, while at least warm, for five or ten minutes, by means of a force pump and spraying nozzle, until the mixture loses its oiliness and becomes like butter. When used, dilute one part of the emulsion with about fifteen of water, and spray it upon the plants by means of a force pump and spraying nozzle. This emulsion is also excellent for the cabbage louse and many other insects. In the report of the United States Department of Agriculture for 1883 may be found a description and figure of a suitable spraying apparatus.
5. Pyrethrum, one ounce to four gallons of water; or, better still, mixed one part with about twenty parts of flour and applied while the dew is on, is an effectual remedy.
6. Hot water, at 130° Fah., will kill the cabbage worms and not injure the leaves. Boiling water, placed in sprinkling cans and taken directly to the field, will be about the right temperature by the time it can be applied. Experiments with a few plants may be needed to enable one to get just the right temperature to kill the worms and not injure the plants.
7. Take half a pound of London purple to thirty pounds of finely pulverized dust of any kind, the finer and drier the better; mix thoroughly, passing all through a meal sieve. Dash a small pinch into the heart of the plant, so that it will settle as dust on all the leaves. Repeat after every rain. Half a pound will serve for one application over forty acres. Store any that remains in a very dry place until again wanted.
8. Professor Gillette, of Colorado, finds the best remedy to be Paris green, thoroughly mixed, one ounce with six pounds of flour, and dusted lightly over the plants while the dew is on.
FUNGUS DISEASES.
There are several parasitic fungi which are more or less destructive to the cauliflower at different stages of its growth. The principal diseases of the cauliflower due to fungi are the following:
Stem Rot.—This is an old disease, which attacks the cauliflower, cabbage and other vegetables in wet seasons. It has received various other names, such as "consumption," "humid gangrene," etc. Professor Comes,[B] who has studied this disease in Italy, believes it to be the same as the "humid gangrene" which occurs in Germany, and which is there attributed to the parasitic attack of the fungus known as Pleospora Napi. He finds this and other fungi present, but does not himself consider them the direct cause of the disease, which he attributes solely to the abundance of manure and moisture in the soil, and an excess of water in the plant, at a time when it is subject to sudden changes of temperature. Beyond a doubt, however, the real cause of the disease is the presence of one or more fungi, whose development is favored by the damp weather. The subject requires further study.
In this country this disease has been reported from Michigan, New York, Maryland and Florida. On Long Island, in 1889,[C] the cauliflower crop was almost entirely destroyed by this disease, which was attributed to the heavy rains at the time the plants were heading. Some fields were a total loss, and from the best fields many of the heads spoiled before they reached the market.