64 PEACH LEAE^ CURL: ITS NATURE AND TREATMENT. 



A bulletin of the Cornell Agricultural Experiment Station, by 

 George F. Atkinson/ which appeared in September, 1894, treats of leaf 

 curl and plum pockets. Respecting the treatment of leaf curl, Mr. 

 Atkinson says that some experiments had been made in various places 

 by spra3'ing the trees with Bordeaux mixture for the prevention of the 

 disease. Some of the experimenters regard it as certain, he states, 

 chat the disease can to some extent be checked by this method, and 

 adds: '' It is quite likely that, in some cases at least, another disease 

 is confused with leaf curl, and this fact might account in those instances 

 for the results claimed." The doubts here expressed as to the results 

 of the work in New York do not appear to have been supported by any 

 field work of the station , and may have arisen from Mr. Atkinson's under- 

 standing of the perennial habits of the fungus causing the disease. 

 There se^ms to have been no winter spraying for curl by the Cornell 

 Station before the spring of 1898, and the results then obtained are in 

 perfect accord with those obtained in 1894 by growers cooperating 

 with the Department. In the spring of 1898 scA'eral experiments were 

 instituted and carried out by B. M. Duggar and H. P. Gould. The 

 results of this work are given in a bulletin by Mr. Duggar, published 

 in February, 1899.' 



The efforts to control peach leaf curl by winter sprays in Canada, 

 so far as concerns the work of the Canadian Government, appear t( 

 have begun nearly simultaneously in Ontario and British Columbia. 



At the experiment farm at Agassiz, British Columbia, the peach 

 orchard had suffered severely from curl prior to the introduction of 

 winter spraying. The superintendent, Mr. Thomas A. Sharpe, 

 reported for 1892 that of the large number of peach varieties at that 

 time on the farm — about 116 — only 5 escaped leaf curl, and the attack 

 was severe.^ In the report for 1893 it is said that leaf curl was worse 

 that 3^ear than ever before. Of about 129 varieties on the farm the 

 Malta was the only variety on the level land that was entirel}^ free.* 

 In the spring of 1894 the trees were sprayed with strong Bordeaux mix- 

 ture when the leaves were partly expanded, but no leaf curl developed 

 that year, even the unsprayed orchards not being troubled by it/ 

 It should be stated here, however, that the work done was too late to 

 have given good results had curl developed, and that it did not properly 

 constitute a preventive spraying. Whether this late spraying was 

 owing to the nature of the season, or whether it was supposed that 

 such treatment would control the disease, is not known to the writer. 



^Atkinson, Geo. F., Leaf Curl and Plum Pockets, Cornell Agr. Exp. Sta. Bull. 

 No. 73, Sept., 1894, pp. 324-326. 



2 Duggar, B. M., Peach Leaf Curl, etc., Cornell Agr. Exp. .^u.. Bull. No. 164, Feb., 

 1899, pp. 377-384. 



8 Kept. Exp. Farms, 1892, p. 278. 



* Kept. Exp. Farms, 1893, pp. 342, 343. 



5 Kept. Exp. Farms, 1894, p. 404. 



