82 



Diseases of Economic Plants 



Results of Experiments for the Control of the Peach Brown- 

 Rot, Marshallville, Ga., 1908 



For the comlnned treatment of peach scab and brown-rot, 

 at least three apphcations of the self-boiled lime-sulfur, 

 8-8-50, are necessary; first, when the petals drop; second, 

 about three weeks later; third, about a month before the 

 fruit ripens. The time of the last application must be deter- 

 mined by the ripening date of the variety. Though a late 

 treatment would be effective against brown-rot, to avoid 

 staining the fruit the last spraying should be made a month 

 before the fruit ripens. Three applications are sufficient for 

 the Elberta and earlier varieties. A fourth treatment is 

 often desirable for later maturing varieties. 



There seems to be no question as to the advisability of 

 spraying the peach orchard where brown-rot and scab are 

 troublesome, but other risks are oftentimes to be encoun- 

 tered. The curculio and other insects readily break the skin 

 of the peach and admit the brown-rot fungus even through a 

 coating of the spray mixture, so that a certain amount of rot 

 may always be expected when the conditions are favorable. 



Scab ^^' '^'- (Cladosporium carpophilum Thtim.). — This 

 disease, which is widespread and so common that many 

 people regard it as an integral part of the peach, may con- 

 sist of isolated, sooty, black specks, or of black specks so 

 numerous as to coalesce into large blotches. These some- 

 times cover as much as one-third or one-half of the peach. 



