56 PEACH LEAF CUKL: ITS NATURE ATSTD TREATMENT. 



trees in 1892.' He says he used a spray in 1892, 1893, and 1894, 

 which was effectual against scale and most fungi. This spray was 

 composed of lime, sulphur, and sulphate of copper, and was applied 

 in the winter. 



In the East, about this time, mildew, brown rot, black spot, rust, and 

 curl were attracting the attention of peach growers and causing 

 serious losses in some sections, and a good many growers were trying 

 summer sprays for the control of one or more of them. Mr. F. P. 

 Herr, of Ridgely, Md., writes^ that for three successive years prior 

 to 1895 he sprayed with limewater, Bordeaux mixture, and arsenical 

 mixtures, and that everything he used produced absolutely negative 

 results, except the arsenites, which injured both foliage and fruit. It 

 would appear probable from these results that the sprays were applied 

 too late to be effective against curl. Mr. L. B. Geiger, of Hoffman, 

 Pa., writes'^ that he was formerly troubled with leaf curl i-n his 

 orchard^ but has had very little of late years. The reason of this, he 

 thinks, is the fact that he has sprayed his peach trees with Bor- 

 deaux mixture several times each year since 1892. He states that at 

 least 75 per cent of the crop of one variety was thus saved. Whether 

 the spray work was done in the winter, or whether, owing to the 

 number of applications made, the summer spray persisted in its action 

 through the following winter, is not known. 



It was in 1892 that Prof. L. R. Taft, of the Michigan Agricultural 

 Experiment Station, first obtained the idea that peach leaf curl could 

 be controlled by the application of winter sprays. This gentleman 

 has supplied the leading facts respecting his work.* He says: "In 

 1892 I was making a series of experiments with Bordeaux mixture 

 and solutions of copper sulphate to learn the strength that could be 

 used upon various plants and trees without injury. These materials 

 were applied at different times, the sprayings being at intervals of 

 about four weeks, from April to July, and while some trees received 

 but one application, others were sprayed two, three, and four times. 

 It was noticed, the trees sprayed in April with either copper sulphate 

 or Bordeaux mixture had no curled leaves, while unsprayed trees and 

 those that were not sprayed until June or July were seriously injured 

 by leaf curl. 



"From the marked difference in the injury from the leaf curl to 

 the sprayed and unsprayed trees, 1 felt very confident that the disease 

 could be held in check to a large extent by the use of fungicides, and 

 in writing Bulletin 92, in December, 1892 (published in March, 1893), 

 I make the statement that ' it is quite certain that the disease can be, 

 to some extent, held in check by their use,' in referring to the effect 



1 Letters dated Medford, Oreg., Dec. 14, 1894. 



^Letter dated Ridgely, Md., Feb. 15, 1895. 



=* Letter dated Hoffman, Pa., Mar. 18, 1895. 



•'Letter dated Agricultural College, Mich., Aug. 31, 1899. 



