The Cauliflower

by A. A. Crozier

The insect enemies of the cauliflower are the same as those which attack the cabbage and other related plants. The four here mentioned require to be specially guarded against. In preparing these notes I am indebted to Mr. L. O. Howard, of the Department of Agriculture, at Washington, for essential aid.

Flea Beetle (Phyllotrea striolata, Fabr).—This insect, also known as the "ground flea" or "Jack," seldom attacks the plants except while growing in the open ground, and is most troublesome in warm, sheltered situations. A safe preventive, therefore, is to grow the plants in beds or frames elevated about three feet from the ground. The objection to this method, aside from the extra labor involved, is the necessity of almost daily attention to see that the soil does not dry out. A supply of water must be conveniently at hand if this method is used, and it is desirable also, to prevent the beds drying out too quickly, to have the earth at least eight inches deep. In hot-beds this insect is seldom troublesome, being probably repelled by the fumes from the manure used. When the seed is sown in the open ground, as practised by many large growers, an extra quantity should be used to ensure against almost certain loss of some of the plants by the flea beetle. The soil should be rich and fine, so that the plants will pass the critical stage as quickly as possible. Sowing radish seeds with the cauliflower is practised by some, as this seed costs but little, and the radishes, coming up first, are attacked by the fleas, which, to some extent, saves the cauliflowers. When the fleas appear, almost any kind of dust will keep them in check somewhat. Lime and ashes are used, but plaster, which adheres to the leaves better, seems equally good. I have had good success with rancid fish oil, mixed as thoroughly as possible with water and sprayed upon the plants. An emulsion made of the oil, in the same manner as hereafter described for kerosene, would enable it to be used to better advantage. A decoction of tobacco, or fine tobacco dust, are standard remedies for this insect.

Cut Worms.—Cauliflower plants being fully twice as valuable as cabbage plants, and it being of more importance to have them started at the proper time, it is necessary to give greater care to protect them from cut worms. Absolutely clean land contains no cut worms, but such land is seldom used on which to plant cauliflower. Sod land, which is generally used, is nearly always full of cut worms. A multitude of remedies have been proposed for this pest, but few of them are of much value. The worms are most abundant and destructive in the latitude of New York during the month of May. Fortunately, cauliflowers are usually set out either earlier than this, for the early crop, so that they become well established and out of reach before their depredations seriously begin, or else, for the late crop, they are set toward the last of June, after the worms have begun to pupate, and are no longer troublesome. Until recently, digging and killing the worms by hand seemed to be almost the only practical remedy. Of late years, trapping the worms under bunches of grass or cabbage leaves, scattered over the ground preparatory to setting the plants, has been successfully resorted to. An improvement upon this method, recommended by the Entomologist of the United States Department of Agriculture, is now in use, and gives excellent satisfaction. It consists in poisoning with Paris green the leaves used to trap the worms, so that there is no need to collect and kill the worms by hand. A good way to do this is to spray with Paris green, in the usual way, a patch of young clover, then cut it and scatter it in small bunches over the cauliflower field a day or two before setting the plants. For the protection of a few plants in the garden, an effectual preventive against cut worms is to surround the stem with a cylinder of paper or tin. This need not touch the plant. One should expect to lose some plants, however, by cut worms, and be prepared with good plants to fill the vacancies.

Cabbage Maggot (Anthomya brassicæ, Bouché)—Dr. J. A. Lintner, State Entomologist of New York, says of this insect: "This is probably the most injurious species of the Anthomyiidæ, as its distribution is very extensive, both in Europe and America, and it has shown at times such capacity for multiplication as to cause the entire destruction of cabbage crops. It commences its attack upon the young plants while yet in the seed-bed and continues to infest them, in several successive broods, until they are taken up in the autumn. The larvæ operate by consuming the rootlets of young plants, and by excoriating the surface and eating into the rind of older ones, or even penetrating into the interior of the root. When they abound to the extent of seriously burrowing the stalk the decay of the root frequently follows in wet seasons, and entire fields are thus destroyed."

The same insect attacks the turnip, cauliflower, and probably other plants. A closely related species is very injurious to the radish. The presence of the insect most frequently becomes manifest upon the cauliflower about two weeks after the plants are set out, and is recognized by the plants ceasing to grow, and wilting or assuming a bluish appearance. Such plants should be at once removed, together with the earth immediately surrounding the root, and fresh plants which have been held in reserve set in their places. The only satisfactory remedies are preventive ones. The seed-bed should be composed of soil taken from the woods, or at least from some place where no cabbages or similar plants have been grown. But the most important precaution is to avoid growing the crop year after year upon the same ground, especially after the insect has made its appearance.

The following remedy, given by Francis Brill, in his pamphlet on "Cauliflowers," is worthy of careful trial. Mr. Brill says: "The ravages of the root maggot have made the growing of early cauliflower, and even early cabbages in many sections, almost an impossibility, but there is a remedy, when the maggot has attacked the roots of the plants, which may be known by a tendency of the leaves to wilt and droop in the heat of the day, very much the same as when affected by club root. Dissolve Muriate of Potash (analyzing 45 per cent. actual potash) in water in the proportion of one tablespoonful to the gallon; or double the quantity of Kainit or common potash salts (13 per cent. actual potash). Apply this directly to the roots, about one gill to each plant, whether seemingly affected or not, for the maggot will have done much harm before the plant will show it, repeating the application as occasion may seem to require. In sections where these maggots have been prevalent it will be well to make a solution of half the above strength, and when the plants are nicely started apply in the same manner as a preventive. Care and judgment must be used not to overdo the matter, thereby killing the plants as well as the maggots. Experiment a little at first."

H. A. March, of Washington, says: "The best thing that I have found for the maggot is a poor grade of sulphur, sulphur before being purified, that smells very strong. Sprinkled over the plants it seems to drive the fly away."

Cabbage Worm (Pieris rapæ, Koch).—The imported cabbage worm, now known all over the country, is the most troublesome enemy which attacks either the cabbage or cauliflower, and the most difficult one with which to deal. It seldom wholly destroys the crop, and is generally a little less destructive after a few years than it is at first, being kept in check by its natural enemies. It never disappears, however, and its numbers cannot be materially diminished for any length of time by artificial means. Among the partial remedies in use are the following:

1. Catch the butterflies with a net when they first appear in spring, before they have laid their eggs. This may keep the insect in check for a year or two when it first makes its appearance, as the butterflies are comparatively slow fliers, and may be caught without much difficulty by a spry boy, especially in the morning when the air is damp.

2. Early in the season keep the young plants excluded from the butterflies, and the whole place free from everything else of the cabbage tribe, except one or more patches of rutabagas or rape, on which the butterflies will lay their eggs. This piece is to be then plowed under.