Root-gall, Root-Knot, Crown-gall, Hairy-root (Bacterium tumefaciens). — Hairy roots or tumerous outgrowths on the roots and root crowns ; sometimes occurs on trunks and limbs. Primarily a nursery disease. Does not seem to be a serious disease on peaches in the North, but is reported as very serious in the South. Attacks a wide range of orchard plants, including apple, pear, brambles, grape, etc.

Control. — Reject all stock showing symptoms.

Rosette. — An obscure southern disease of peach trees and some kinds of plums, characterized by bunchy growths containing very many rolled and yellowish leaves which fall prematurely. The tree dies the first or second year. There is no premature fruit as in yellows. It is often accompanied by gummosis of the roots. The disease is communicable by budding, and it may enter through the roots. All affected trees should be exterminated. Known in South Carolina, Georgia, Kansas, and Arkansas.

Scab or Black-spot (Cladosporium carpophilum). - Black scablike spots on the fruit, often causing it to crack deeply.

Control. - Self-boiled lime-sulfur, as applied for Brown-rot.

Yellows. - A fatal disease of peaches ; also attacks nectarine, almond, apricot, and Japanese plum. Cause unknown. The first symptom in bearing trees is usually the premature ripening of the fruit. This fruit contains definite small red spots, which extend towards the pit. The second stage is usually the appearance of " tips," or short, late, second growths upon the ends of healthy twigs, and which are marked by small, horizontal, usually yellowish leaves. The next stage is indicated by very slender shoots, which branch the first year and which start in tufts from the old limbs, bearing narrow and small yellowish leaves. Later the entire foliage becomes smaller and yellow. In three to six years the tree dies. The disease spreads from tree to tree. It attacks trees of any age. Known at present only in regions east of the Mississippi. Peculiar to America, so far as known.

Preventive. - Pull up and burn all trees as soon as the disease appears. Trees may be reset in the places from which the 1 yellows " trees were taken. Laws aiming to suppress the disease have been enacted in most peach-growing states, and the enforcement of them will keep the disease well under control. Pear. Blight {Boxillus amylovorus). - A very serious bacterial disease. Bacteria winter just at the edge of the dead wood in trees blighted the previous year. With the advent of warm spring days they ooze through the bark in sticky drops and are carried by bees and flies to blossoms. The blossoms blight, and the spur may also blight. Plant-lice carry bacteria from blighted blossoms to spurs and shoots. If a spur becomes blighted, the bacteria may spread in the bark of the limb, causing a depression or canker. This may girdle the limb and cause its death. The leaves turn black and stick tenaciously, even through the winter. Succulent water sprouts are very apt to blight and cause large cankers. Generally distributed in North America, and known only in America. Attacks apple, quince, mountain ash, hawthorn; the Spitzenburgh is specially liable to attack.

Control. — Clean up hedgerows of hawthorn, old blighted pear trees and apple trees. In early spring cut out the blight of the previous year and disinfect the stubs with corrosive sublimate, 1-1000. Clean out cankers with a sharp knife, and disinfect. Paint over with lead paint. At blossoming time make a systematic daily inspection for blossom blight, and break it out. Watch for blight in the shoots. When it appears get a long-handled pruning-hook, fasten a sponge near the knife, and saturate it with corrosive sublimate solution, 1-1000. Clip out the blighted twigs, cutting five or six inches below the blight, and sop the pruned stub with the sponge. During a blight epidemic, drop all other work. The work must be done systematically and persistently, or not at all. One week's work may save the pear crop and the pear trees. Leaf-blight and Cracking of fruit (Fabrea maculata). — Attacks nursery stock of pears and quinces, beginning as small circular brown spots on the leaves. These spread, and if numerous cause the leaf to fall. The same disease produces a black spot or pit on the fruit.