58 PEACH LEAF CURL: ITS NATURE AND TREATMENT. 



spraying for scale. These marked trees were scattered, here and there 

 one, throughout the entire 40-acre block. In February the marked 

 trees were very thoroughly sprayed over all parts, as much as two 

 gallons of spray being applied to each tree. After this work was 

 completed the entire block, with the exception of the trees already 

 treated, was sprayed as high as the forks of the main limbs, thus 

 avoiding any injury to swelling buds. As before stated, curl devel- 

 oped seriously in the Sacramento Valley in the spring of 1893, and 

 the result was that the unsprayed trees, as well as those sprayed 

 only on the main limbs, were nearly denuded by the disease, while 

 the scattered trees which had been sprayed throughout were in 

 full and vigorous foliage and growth. In the writer's notes upon the 

 examination of this orchard on May 22, 1893. it is stated that the 

 trees fully treated in this block were loaded with fruit and in full leaf, 

 while the trees sprayed only to the forks of the limbs were nearly bare 

 and alm'ost wholly destitute of fruit on the unsprayed parts. Such 

 fruit as was found on the unsprayed branches was inferior in size and 

 quality. It is further stated that the absence of fruit on the untreated 

 branches as compared with the aliundant yield of the treated branches 

 gives such a striking contrast as to be almost beyond belief.^ 



Mr. William N. Runyon, of Courtland, Cal., treated a large acreage of 

 peach trees with lime, sulphur, and salt in the winter of 1892-93. He 

 states that the trees sprayed once while dormant were practically free 

 from curl, while trees of the same variety not sprayed were badly 

 affected.'^ He also ^ives an observation of interest in connection 

 with the habits of the fungus, and one since indorsed by the writer, 

 that is, that the disease '' will not spread from an unsprayed to a sprayed 

 tree." In letters from Mr. Runyon^ relative to this work, he 

 remarks that although he had heard that a mixture of lime, sulphur, 

 and salt was beneficial in controlling curl, he had no idea that the result 

 would be so nearly a complete prevention. He says that it was only 

 when curl leaf had become quite prevalent on unsprayed trees that 

 he noticed its almost total absence on those that had been sprayed. 

 The most striking instance, he states, was where about 50 three year 

 old nectarine trees stood in rows adjoining about a dozen full-grown 

 trees of the same variety that had shown curl for years. The young 

 trees, hot having shown any scale, were left unsprayed, and were a 

 mass of curl, while the old trees, which were given the regular treat- 

 ment, were almost entirely free. In this orchard about 60 acres of 

 peach trees were also sprayed, the work being done about the 1st of 



» F(jr further notes and tabulated records of some of this work of the spring of 

 1893 the reader is referred to Chapter YII under Notes on the Auxihary Experi- 

 ments in Cahfornia. 



2 Answer to circular letter of Nov. 25, 1893. 



3 Letters dated Courtland, Cal., Jan. 31, and Mar. 8, 1894. 



