Control. - No satisfactory method known. The most that can be done is to go over the patch three or four times during the summer, cut out and burn the blighted canes. Ginseng. Blight (Alternaria panacis). - Papery brown spots on the leaves, which spread until the whole leaf is involved. Also attacks the seed heads, producing a blast.
Control. - In the spring before the plants come through the ground spray the soil thoroughly with copper sulfate, 1 pound to
10 gallons of water. As the plants are breaking through the soil, spray with bordeaux, 3-3-50. Spray repeatedly while the plants are coming through the ground, making a special effort to cover the stems. Keep all growth covered with spray throughout the summer. Spray the seed heads thoroughly just after the blossoms fall, and again when they are two-thirds grown. Destroy all diseased tops. Fiber Rot (Thielavia basicola). - Commonly called rust or rusty root, from the characteristic appearance. The plants eventually wilt and die.
Control. - Treat the soil with acid phosphate at the rate of 1000 pounds to the acre. Dip the roots in bordeaux mixture, 3-3-50, before planting. Mildew (Phytophthora cactorum). - Attacks tops shortly after they come up.
Control. - Thorough spraying early, as for blight, will control this disease. Wilt (Acrostalagmus sp.). - A sudden wilting of the whole plant, caused by the action of the fungus in the sap tubes of the root.
Control. - Remove the wilted plants as soon as discovered in order to prevent further spread. Root-rot. - Caused by various soil organisms. Favored by wet, soggy soil.
Control. - Underdrain the soil thoroughly. Golden-seal. - Consult treatments under Ginseng. Gooseberry. - Mildew (Sphaerotheca mors-uvce). - A powdery mildew attacking the fruit and young growth of English varieties of gooseberpy.
Control. - As soon as the leaves begin to unfold, spray with potassium sulfid, 1 ounce to 2 gallons of water. Rust (AEcidium grossularice). - Orange-colored rust pustules on the fruit and under side of the leaves.
Control. - Early spraying as for Mildew. Keep down sedges and grasses.
Grape. Anthracnose (Sphaceloma ampelinum). - Occurs on the fruit as a definite dark brown spot with a lighter auriole ; on canes as deep pits with an elevated red margin, and on veins of the leaves, causing the leaves to crimp. Occurs on all varieties, especially Roger's hybrids. Not so abundant as formerly.
Control. - It is said that an early spraying before the buds open with sulfate of iron, 100 pounds to 50 gallons of water, is very important. Later sprayings for black rot will also be effective in preventing spread.
Black-rot (Guignardia bidwellii). - The most serious disease of grapes east of the Rocky Mountains, especially southward. Attacks all green parts. Produces a brown circular spot on leaves, a black, elongated, sunken pit on petioles, canes, etc., and on the berry a brown rot with shriveling and wrinkling ; finally the berry becomes black and hard.
Control. - This disease may be controlled by timely applications of bordeaux mixture, 4-4-50. It is of great importance that spraying be done before rain storms, as the berry enlarges so rapidly. Spray (a) when the third or fourth leaf has unfolded ; (b) as soon as the blossoms have fallen; (c) when the berries are the size of a pea ; (d) in about two weeks. In a wet season make two more applications. After July 20 make the bordeaux 4-2-50, or use ammoniacal copper carbonate. In case of dense foliage all applications except the first two should be made by hand. Attach trailers to the sprayer, and have two men following to apply the spray directly to the clusters. About ten acres can be sprayed in a day, and the total cost of labor and material should not exceed 75 cents per acre for each application.
California Vine-disease. - An obscure disease, which destroyed thousands of acres of vines in California. Cause not known, and at present practically unknown and of no importance economically.