The following advice (mostly adapted from Whetzel and Stewart) covers the most frequent types of fungous disease appearing to the home gardener. Many other kinds, however, will almost certainly attract his attention the first season if he looks closely. The standard remedy is bordeaux mixture; but because this material discolors the foliage the carbonate of copper is sometimes used instead. The treatments here recommended are for New York; but it should not be difficult to apply the dates elsewhere. The gardener must supplement all advice of this character with his own judgment and experience, and take his own risks.

Apple Scab

Usually most evident on the fruit, forming blotches and scabs. Spray with bordeaux, 3-3-50, or lime-sulfur, 1-40; first, just before the blossoms open; second, as the blossoms fall; third, 10 to 14 days after the blossoms fall. The second spraying seems to be the most important. Always apply before rains, not after.

Asparagus Rust

The most common and destructive disease of asparagus, producing reddish or black pustules on the stems and branches. Late in the fall, burn all affected plants. Fertilize liberally and cultivate thoroughly. During the cutting season, permit no plants to mature and cut all wild asparagus plants in vicinity once a week. Rust may be partially controlled by spraying with bordeaux, 5-5-50, containing a sticker of resin-sal-soda soap, but it is a difficult and expensive operation and probably not profitable except on large acreage. Begin spraying after cutting as soon as new shoots are 8 to 10 in. high and repeat once or twice a week until about September 15. Dusting with sulfur has proved effective in California.

Cabbage And Cauliflower Diseases

Black-rot is a bacterial disease; the plants drop their leaves and fail to head. Practice crop rotation; soak seed 15 min. in a solution made by dissolving one corrosive sublimate tablet in a pint of water. Tablets may be bought at drug stores.

Club-root or club-foot is a well-known disease. The parasite lives in the soil. Practice crop rotation. Set only healthy plants. Do not use manure containing cabbage refuse. If necessary to use infested land, apply good stone lime, 2 to 5 tons per acre. Apply at least as early as the autumn before planting;' two to four years is better. Lime the seed-bed in same way.

Carnation Rust

This disease may be recognized by the brown, powdery pustules on the stem and leaves. Plant only the varieties least affected by it. Take cuttings only from healthy plants. Spray (in the field, once a week; in the greenhouse, once in two weeks) with copper sulfate, 1 lb. to 20 gal. of water. Keep the greenhouse air as dry and cool as is compatible with good growth. Keep the foliage free from moisture. Train the plants so as to secure a free circulation of air among them.

Chestnut

The bark disease of chestnut has become very serious in southeastern New York, causing the bark to sink and die and killing the tree. Cutting out the diseased places and treating aseptically may be useful in light cases, but badly infected trees are incurable, in the present state of our knowledge. Inspection of nursery stock and burning of affected trees is the only procedure now to be recommended.. The disease is reported in New England and western New York.

Chrysanthemum Leaf-Spot

Spray with bordeaux, 5-5-50, every ten days or often enough to protect new foliage. Ammoniacal copper carbonate may be used, but it is not so effective.

Cucumber Diseases

"Wilt" is a disease caused by bacteria that are distributed chiefly by striped cucumber beetles. Destroy the beetles or drive them away by thorough spraying with bordeaux, 5-5-50. Gather and destroy all wilted leaves and plants. The most that can be expected is that the loss may be slightly reduced.

Downy mildew is a serious fungous disease of the cucumber known among growers as "the blight." The leaves become mottled with yellow, show dead spots, and then dry up. Spray with bordeaux, 5-5-50. Begin spraying when the plants begin to run, and repeat every 10 to 14 days throughout the season.

Currant Diseases

Leaf-spots and anthracnose are caused by two or three different fungi. The leaves become spotted, turn yellow, and fall prematurely. They may be controlled by three to five sprayings with bordeaux, 5-5-50, but it is doubtful whether the diseases are sufficiently destructive on the average to warrant so much expense.

Gooseberry Powdery Mildew

The fruit and leaves are covered with a dirty white growth of fungus. In setting a new plantation, choose a site where the land is well underdrained and where there is a good circulation of air. Cut away drooping branches. Keep the ground underneath free from weeds. Spray with potassium sulfide, 1 os. to 2 gal.; begin when the buds are breaking and repeat every 7 to 10 days until the fruit is gathered. Powdery mildew is very destructive to the European varieties.

Grape Black-Rot

Remove all "mummies" that cling to the arms at trimming time. Plow early, turning under all old mummies and diseased leaves. Rake all refuse under the vine into the last furrow and cover with the grape hoe. This cannot be too thoroughly done. The disease is favored by wet weather and weeds or grass in the vineyard. Use surface cultivation and keep down all weeds and grass. Keep the vines well sprouted; if necessary sprout twice. Spray with bordeaux mixture, 4-4-50, until the middle of July, after that with ammoniacal copper carbonate. The number of sprayings will vary with the season. Make the first application when the third leaf shows. Infections take place with each rain, and occur throughout the growing season. The foliage should be protected by a coating of the spray before every rain. The new growth especially should be well sprayed.

Hollyhock Rust

Fig. 212. Eradicate the wild mallow (Malva rotundifolia). Remove all hollyhock leaves as soon as they show signs of rust. Spray several times with bordeaux mixture, taking care to cover both sides of leaves.