442 STtATE BOARD OF AGRICULTURE. 



tained a pressure of about 225 pounds. A large power duster was used for 

 dusting and the material was applied from two directions at each application. 

 The work was usually done early in the morning but atmospheric conditions 

 were not always satisfactory. 



The description of the experiment in the Hawley orchard will be given 

 here and the results of both experiments will then be discussed together. 



EXPERIMENT ON THE HAWLEY FARM. 



Another experiment was conducted on the H. E. Hawley farm in a block 

 of 100 twelve-year-old Bartlett trees. This orchard is farther from the lake. 

 Most of the trees bore a fair to good crop of fruit in 1920 but in 1919 there 

 was such a light crop that very little spraying was done and much scab 

 developed. 



Materials and applications. This block was divided into four plots and 

 treated with the same materials as listed in the preceding discussion of the 

 Merritt experiment. The only difference being that lime-sulphur was used 

 at the rate of 1-40 instead of 1-50. The applications were made at the same 

 periods as in previous experiment but all of each plot received the "pre- 

 pink" application. This experiment, then, was a comparative test of lime- 

 sulphur, sulphur dust and copper sulphate dust, applied according to a 

 schedule which calls for the first application when the buds are in the "pre- 

 pink" stage. 



Weather conditions. The early part of the season was very favorable for 

 scab development because of frequent rainfall during the period when the 

 blossom buds were expanding. The control of scab during this period was 

 difficult because of cool weather which prevailed for some time after the buds 

 had reached the "pre-pink" stage. The buds developed slowly and there 

 was excellent opportunity for scab infection on portions of the blossom stems 

 or buds that became exposed after the "pre-pink" stage but before the time 

 of the pink application. After the blooming period the weather was. quite 

 dry and unfavorable to scab development. This statement of weather con- 

 ditions apphes to both orchards, although the conditions during the summer 

 were probably more favorable for scab in the Merritt orchard because of its 

 proximity to the lake. 



RESULTS. 



Scab control. Counts were made in the Merritt orchard from a bulk lot 

 of fruit picked from a large number of trees of each plot. Counts giving the 

 results of the "pre-pink" application were made only on the sulphur dust 

 plot because of the fight crop. The number of applications given each group 

 in the following table is indicated by the numbers in the column headed 

 "appfications". Number 1 — refers to the "pre-pink", 2 — to the pink or 

 cluster, 3 — to the calyx application, and 4 — to the one made two weeks after 

 the calyx application. 



