6 BULLETIN 543, TJ. S. DEPARTMENT OP AGRICULTURE. 



During 1914 there was no fruit on any of the trees in this orchard, 

 the fruit buds in the peach orchards of northwestern Arkansas having 

 been killed by low temperatures in January. 



The experiments of 1915 were conducted in the same orchard as 

 were those of 1914. Plat 1, consisting of 34 trees, was treated with 

 nitrate of soda at the rate of 2 pounds per tree; plat 2, consisting of 

 24 trees, was treated with nitrate of soda and dried blood at the rate 

 of 1^ pounds of the former and 1 pound of the latter per tree. Six 

 trees between these two plats were left untreated and were con- 

 sidered as checks, as was also the remainder of the orchard. 



Owing to the press of other work, the fertilizers were not applied 

 until May 22. The orchard had been cultivated a week before and 

 was again cultivated on June 1. The trees had bloomed on April 25 

 and had set a good crop. 



On June 10 there was very little of the disease on the nitrate plats, 

 but considerable was beginning to show on the untreated plats. 

 The large dark-green leaves of the nitrate plats were in sharp con- 

 trast to the relatively pale leaves of the unfertilized plats. By June 

 30 the contrast was much greater, as the disease had given a ragged 

 appearance to the foliage of the untreated plats, while the nitrate 

 plats remained nearly free from infection. 



On August 5 the fruit was just beginning to ripen. On certain 

 limbs of the untreated trees there was considerable injury to the 

 fruit, though not enough to be of importance commercially. The 

 fruit of one limb, for instance, would be badly affected, while that of 

 the remainder of the tree would be free from injury. There was 

 almost no injury to the fruit of the nitrate plats. 



By the end of the season the difference in the appearance of the 

 foliage of the nitrate plats and the untreated ones was as great as 

 during the previous season. The difference between this damage 

 and the total damage caused by the bacterium was about the same 

 on both the fertilized and unfertilized trees as during the previous 

 season. There was no perceptible difference between plats 1 and 2 

 in so far as the amount of infection was concerned. Eight of the 

 fertilized trees which bordered on the meadow were considerably 

 more affected than the others in the same plats, but were infected 

 much less than the unfertilized trees. 



During both years the nitrate plats included the trees which during 

 1913 suffered the heaviest infection. Sixteen of the trees treated 

 with nitrate of soda in 1914 were included in the nitrate plats in 1915. 

 These, however, showed no superiority, in so far as resistance to the 

 disease was concerned, over those which had not received fertilizer 

 during the previous year. In the experimental plats of both 1914 

 and 1915 the sole difference in the treatment of the plats, including 

 the check plats, was one of fertilization. All had been given the 



