Alfalfa. Leaf Spot (Pseudopeziza medicaginis).— Small black spots on the leaves. Causes the leaves to turn yellow and fall.

Control. — Frequent close mowing usually holds the disease in check.

Dodder (Cuscuta epithymum).—A tangled mat of yellow threads entwining the alfalfa stems. Usually appears in spots in the field and spreads from these points. Is easily spread by the rake, and especially in seed. Dodder is not a fungus, but a specialized parasitic plant of the morning-glory family.

Control. - As soon as discovered, cover the infested spot with straw and oil and burn. Screen the alfalfa seed to remove seed of . dodder. Make a screen 12 inches square by 3 inches deep with a 20 X 20 mesh wire-cloth made of No. 34 steel wire. Sift each half pound of seed vigorously for one half minute. Almond. Blight (Coryneum beyerinkii). - See Peach Blight, p. 275.

Yellows. See under Peach. Apple. Blight. - The same disease as Pear Blight, which see.

Bitter-rot or Ripe-rot (Glomerella rufomaculans). - Produces a browning and drying of the fruit. Progressing in concentric rings from a central point. Attacks nearly mature fruit. Also occurs on limbs, where it produces a canker scarcely distinguishable from New York apple-tree canker (p. 264).

Control. - Trim out all cankers early in the spring, and remove all mummied apples from the trees. In addition to the sprayings for apple scab, make three, four, or five sprayings with bordeaux mixture, 3-3-50, according to the severity of the disease and the character of the summer as regards rainfall.

Black-rot of fruit. — Fruit stage of the New York apple-tree canker disease, which see.

Blotch (Phyllosticta solitaria).- Attacks fruit, twigs, and leaves. Blotches a quarter of an inch or more in diameter appear on the fruit. These often coalesce, and the fruit often cracks deeply. Scurfy cankers are formed on the twigs while very small; circular spots a quarter of an inch in diameter are formed on the leaves. Ben Davis is especially susceptible.

Control. - Careful pruning to remove cankered twigs. Spray as for apple scab and bitter rot.

Brown-rot.- See under Cherry (p. 267).

Canker. - Smooth cankers in bark of trunk and limbs usually indicate blight, rough ones New York apple-tree canker.

Collar-rot. - A dead area in the bark near the ground ; often girdles the tree. Cause not known. May be started in some cases by the fire-blight organism, in others by winter injury. Common on King, Baldwin, and Ben Davis.

Remedy. - As soon as noticed, cut away dead bark and wood to the living healthy tissue. Swab the wound with a solution of corrosive sublimate, 1:1000, and paint over with a lead paint which is free from turpentine. Slit the callus on the edge from year to year to make it spread faster, and keep dead wood well protected with paint.

Crown-gall {Bacterium tumefaciens). — See under Peach, p. 276.

New York Apple-tree Canker (Sphceropsis malorum). — The fungus causing the disease attacks limbs, causing roughened cankers and often girdling the limb ; attacks leaves, causing a reddish brown leaf-spot, and on the fruit produces a black rot. Abundant on Twenty Ounce.

Control. — Remove and burn old cankers. Clean out and disinfect small cankers as for collar-rot. Soak old limbs well with spray mixture when spraying for scab. Spraying as for apple scab usually controls black rot of fruit, though in the Ozark region a late spraying may be advisable for leaf-spot. Cultivate thoroughly.

Powdery Mildew (Sphcerotheca leucotricha). — Attacks nursery stock, covering the leaves with a grayish white, powdery mildew. Also on leaves and twigs of new growth in the orchard, often causing the leaves to fall.

Remedy. — Lime-sulfur, 1-40, as applied for scab is a specific.

Rust (Gymnosporangium macropus). — A bright yellow rust appearing on the young leaves and fruit. Enfeebles the whole tree and produces one-sided fruits. It is known that one stage in the cycle of the fungus is the cedar apple, which occurs on the red cedar. Apples are always infected from the cedar, never from apple to apple.