172 THE PEACHES OF NEW YORK 



Preventive remedies have so far met with but indifferent success; probably 

 the best method of control is to destroy the mummy-like fruits and all 

 other sources of infection either by picking them from the trees, or much 

 better by plowing them under deeply. Even so it is impossible to exter- 

 minate all of the countless myriads of brown-rot spores. Spraying with 

 the self -boiled lime-sulphur mixture three times at intervals of three weeks, 

 beginning as the calyxes drop, is the appointed preventive but the results 

 are uncertain, as this is one of the diseases in which it is difficult to touch 

 the spot in spraying. Varieties of peaches show various degrees of sus- 

 ceptibility to brown-rot. 



Peach leaf-curl {Exoascus deformans (Berk.) Fuckel) is the best- 

 known and probably the most prevalent fungus disease of the peach in 

 New York. The disease appears in early spring as the leaves unfold and 

 continues until warm, dry, summer weather prevails. The name describes 

 the disease so that all may know it — the leaves curl, then become puckered, 

 distorted and much thickened, turn from normal green to yellow, tinged 

 with red, and finally fall. In severe cases the trees may be defoliated, 

 though a second covering of leaves almost always comes out. Leaf-curl 

 is most prevalent and most virulent in cool, moist weather. The disease 

 is easily controlled by spraying with lime-sulphur, bordeaux mixttire or 

 any other good fungicide applied while the trees are dormant. 



In common with other species of Prunus the foliage of peaches is 

 attacked by several fungi which produce diseased spots on the leaves, the 

 dead areas usually dropping out leaving holes as if punctured by shot, 

 giving the names " shot-hole fungus," " leaf -spot " and " leaf -blight." 

 Two fungi are in the main responsible for these leaf -troubles, Cylindros- 

 porium padi Karsten and Cercospora circumscissa Saccardo. The ravages 

 of these fungi are prevented by the use of the self-boiled lime-sulphur 

 mixture. With these, as with other fungi, cultivation has a salutary 

 effect as it destroys diseased leaves which harbor the fungi during their 

 resting period and keeps the trees vigorous enough to resist the fungi. 



Peach-scab {Cladosporium carpophilum Thiim.) is a common and 

 destructive fungus in peach-growing districts on the Atlantic seaboard 

 and is found rather frequently in New York but seldom does much injiory 

 in the State. It appears in sooty, black spots and blotches on the surface 

 of the peach, causing atrophy and hardening of the parts affected which, 

 in severe cases, crack badly. Twigs and leaves may be affected. White- 

 fleshed sorts suffer most and are ruined for the market even in mild attacks. 



