72 PEACH LEAF CURL*. ITS NATURE AND TREATMENT. 



effects of one year's treatment extended to the crop or foliage of the 

 second year. 



AVhile peach leaf curl did not develop seriously in the Sacramento 

 Valley in 1894, it prevailed quite extensively in other portions of the 

 United States. This resulted in acquiring facts bearing on the experi- 

 ments for 1895 in the Rio Bonito orchard. The experiments planned 

 by the Department and carried out by growers in the East and in the 

 north Pacific States, where leaf curl developed, showed that one 

 thorough spraying during the dormant period of the tree was sufficient. 

 The experiments of 1895 were consequently modified from those of 

 1894 in respect to the number of applications made, as well as in other 

 respects found to be advisable. 



SPRAT WORK CONDUCTED IN 1895. 



In the spray work in the Rio Bonito orchard during the winter and 

 spring of 1895, the same block of Lovell peach trees was selected as 

 that treated the previous year, and in each case the same unsprayed or 

 control rows were left as in 1894. In 1895 the number of experiments 

 made in this block was 38, as in the previous year, but three of the 38 

 rows were not sprayed, being left without treatment for the purpose 

 of observing the action of sprays applied in 1894 upon the crop and 

 foliage of 1895. These three rows were numbers 4, 24, and 53, each 

 of which had received two treatments in 1894. The facts thus learned 

 are considered farther on. The spray work of 1895 included but a 

 single spraying of each row designed for treatment. As already indi- 

 cated, each experunent included one treated and one untreated row, 

 each row having 10 immediately adjoining trees. By treating one row 

 on either side of each control row the latter served as a contrast row 

 for both sprayed rows. By referring to the plat of the block, p. 69, 

 this arrangement may be seen. Row 1 is sprayed; row 2, unsprayed; 

 row 3, sprayed. These three rows make two experiments — rows 1 

 and 2 compared make the first experiment, while rows 3 and 2 com- 

 pared make the second experiment. In like manner rows 4 and 5 and 

 5 and 6 make two experiments. These illustrations will be sufficient, 

 as the entire block, with the exception of the three rows already 

 noted, was treated according to the same general plan. 



In considering the application of sprays in the experiments of 1895, 

 the nature of the sprays used, the formulae according to which they 

 were prepared, the location of the rows treated, and the dates of appli- 

 cation, as well as the location of the control rows for comparison, are 

 set forth in the table which follows. That the reader may better grasp 

 the nature of all treatments which each row had received the previous 

 year, the formula for the sprays applied in 1894 are placed at the left 

 of the treatment given the same rows in 1895. 



