EXPERIMENT STATION BULLETINS. 



463 



TABLE 13. HOLDING TEST OF WARK PEACHES_, 1921. 



The fruit from the plot dusted once only was found to be considerably 

 riper than that from the other plots so that on August 12 it was so ripe that 

 it had to be discarded. This condition would, of course, make the control 

 of brown rot more difficult. It may have been also due to the fact that the 

 fruit did not receive the first application. The difference in the condition on 

 August 13, of the fruit from the check plot and the plot dusted twice, was 

 marked. The fruit from the check plot was almost a total loss while that 

 from the dusted plot was in good condition. 



Hill's Chili and Gold Drop Peaches. Two blocks of Hill's Chih and one of 

 Gold Drop were used in an experimental way. One block of Chili trees con- 

 sisted of large, mature trees which were fillers in an apple orchard. The 

 other was a block of about 75 young bearing trees. The Gold Drops were also 

 mature trees set as fillers in an apple orchard. Gold Drop is a variety not 

 usually considered very susceptible to brown rot, but Hill's Chili, a susceptible 

 variety, usually rotted badly in these orchards in previous years. 



No early summer applications of dusting or spraying materials were made 

 on any of these trees. The Hill's Chili trees received an apphcation of sul- 

 phur dust on July 28. All trees were dusted, no check or untreated plot being 

 left at this time. The Gold Drop trees did not receive this application. 

 When the special application was made on August 31, check plots were left 

 untreated in each block of trees. Care was taken that these check plots were 

 not located in positions that were more favorable to rot development than the 

 dusted portions of the orchards. Where there was much variation in eleva- 

 tion, the check plots were located on the high ground so that they would have 

 the advantage of better air circulation. 



On August 31, when the dusting was done, conditions were ideal for such 

 work. The trees were wet from rain which had fallen during the night and 

 remained in this condition most of the forenoon. The dusting was finished 

 by 10:00 A. M. and there had been no wind to interfere. All trees were 

 dusted from two directions. 



RESULTS. 



Control of brown rot before harvest. On all Chili trees which were well 

 dusted, there was very little development of rot previous to the time the fruit 

 was picked. On the check trees of the young orchard the fruit rotted badly, 

 while on the check trees of the old orchard the presence of rot was indicated 

 largely by the fruit which dropped. The rot usually developed near the stem 

 end of the fruit and thus caused it to drop before the entire peach was decayed. 

 By the time the first peaches were ready to pick, there was much fruit on the 



