CONTROL OF PEACH BACTERIAL SPOT. 5 



ducted in that section of the orchard. The trees themselves had 

 been well pruned and were of good average size. The soil was, 

 in texture, good peach soil, but inclined to be somewhat lacking 

 in natural fertility. 



In 1914 treatment was as follows: Plat 1, consisting of 18 trees, 

 received 2 pounds of nitrate of soda per tree; plat 2, consisting of 6 

 trees, received 1 pound of nitrate of soda per tree; plat 3, consisting of 

 12 trees, received 3 pounds of nitrate of soda per tree; plat 4, consist- 

 ing of 18 trees, received 3 pounds of bone meal per tree; plat 5, con- 

 sisting of 12 trees, received 6 pounds of bone meal per tree; and plat 

 6, consisting of 12 trees, received 4 pounds of acid phosphate per tree. 

 The f ertilizer was applied on May 4 in a ring or band about the trees, 

 directly below the ends of the branches. The application of fertilizer 

 was immediately followed by cultivation. 



On June 8 the disease was evident, though not as yet serious, in 

 all the plats, including both treated and untreated trees. The 

 amount of infection in all plats appeared to be about equal. Each 

 plat had some trees which were next to the meadow, the grass of 

 which extended nearly to the trunks of the trees. In all cases these 

 trees, deprived by the meadow of their proper share of food materials 

 and moisture, were the worst affected. By July 2 plats 1, 2, and 3 

 (the nitrate plats) showed few leaf infections except in the case of 

 the trees close to the meadow. Even these, however, were much 

 freer from the disease than were the untreated trees. The leaves of 

 the unfertilized trees showed considerable injury, about 20 per cent 

 of them being affected. Plats 4, 5, and 6 (the bone-meal and acid- 

 phosphate plats) appeared to be somewhat better than the untreated 

 portion of the orchard, but the difference was not nearly so striking 

 as the difference between the nitrate-of-soda plats and the untreated 

 trees. 



By the end of the season the untreated trees had lost fully one- 

 third of their leaves. Of the remaining leaves, about 30 per cent 

 showed some injury from the disease. On the nitrate-of-soda plats 

 there was little def oliation from the disease, and few leaves showed any 

 infection. Most of the injury was on the trees next to the meadow. 

 The leaves of the trees in these plats were large and possessed the 

 dark-green color characteristic of healthy peach leaves, which is the 

 usual effect of fertilizing peach trees with nitrate of soda. Plats 4, 5, 

 and 6 (the bone-meal and acid-phosphate plats) were in somewhat 

 better condition than the untreated plats, but not especially so. It 

 will be noted that, while at the beginning of the season injury from 

 the disease was slight and about the same in all the plats, it later in- 

 creased and became commercially important only on those plats 

 which had not received the nitrate-of-soda treatment. 



