62 PEACH LEAF CURLI ITS NATURE AND TREATMENT. 



were sent to a number of orchardists in the peach-growing centers 

 of Ohio in the winter of 1893-94. During this and the succeeding 

 winter over fifty orchardists, located in twenty-five difi'erent peach- 

 growing centers of the State, received carefully prepared instructions 

 for winter spraying for curl. The instructions for both winters were 

 planned, in the usual manner of experimental work, a number of 

 unsprayed or control trees being left for comparison with the trees to 

 be treated with each spray to be tested. The object in thus planning 

 the work was the same as for that in Michigan and elsewhere — that is, 

 to obtain such striking contrasts between sprayed and unsprayed trees 

 that they would form long-remembered object lessons for all who 

 should chance to see them. 



The spray work of the Ohio Agricultural Experiment Station after 

 1890 was quite extensive; but the treatment of peach leaf curl is not 

 mentioned in the bulletins on orchard spraying published by that 

 station in December, 1891, and February, 1893,^ although in the 

 latter (Bui. No. 48, p. 12) the spraying of peach trees for other 

 diseases is considered. In the spring of 1893, however. Prof. W. J. 

 Green sprayed a considerable number of 3"oung peach trees, just 

 planted, the object being ""to deteiTnine the truthfulness of the 

 ><tatements that had been made concerning the effect of spraying upon 

 peach trees." In relation to curl, Professor Green says that he "did 

 not see any effect until the season of 1894," during which and in 1895 

 ''there was some effect noticeable." He says further, in this connec- 

 tion: "'I am aware that other work in this direction had been done 

 before 1 commenced, because I received my suggestions from some 

 other source, but I can not now recall the particular case." (Letter 

 dated September 30, 1899.) 



Upon these results obtained by Professor Green, and supported by 

 the work of Benton in California and Taft in Michigan, were based 

 the subsequent experiments of Prof. A. D. Selby in the orchard of 

 William Miller, of Gypsum, Ohio.^ These experiments were begun, 

 according to Professor Selby, in April, 1895,^ but no results with 

 leaf curl were obtained until 1896,* as in 1895 there was no difference 

 between sprayed and unsprayed trees in the amount of curl developing, 

 it being so insignificant as to be without evident effect. The curl 

 which developed in 1896 enabled Mr. Selby to obtain some contrasts 

 between sprayed and unsprayed trees, but these contrasts were not as 



1 Green, W. J., The Spraying of Orchards, Ohio Agr. Exp. Sta. Bui. No. 9, Dec, 

 1891, Vol. IV, second series; Bui. No. 48, Feb., 1893, p. 12; and a letter from Pro- 

 fessor Green, dated Wooster, Ohio, Sept. 30, 1899. 



^Letter from Prof. A. D. Selby, dated Wooster, Ohio, Sept. 13, 1899. 



'L. c; also Ohio Agr. Exp. Sta. Bui. No. 92, March, 1898, pp. 237-24.5. 



♦Ohio Agr. Exp. Sta. Bui. No. 92, March, 1898 p. 245; also Thirtieth Ann. Rept. 

 Ohio State Hort. Soc, pp. 87, 



