2G THE CONTROL OF APPLE BITTER-KOT. 



group of plots that the ideal treatment would have been live applica-. 

 cations at intervals of two weeks, beginning June 12. Comparing 

 Nos. 12 and 15, it is further noted that a dela}- of two weeks— from 

 July 10, the date the first application was given No. 15, to July 25, 

 the date treatment began on No. 12— made a difference of 37.3 per 

 cent in favor of the earlier applications, representing the difference 

 between success and failure. 



Considering the series of Plots 2 to 8, which combine the three early 

 applications for scab and the later applications for bitter- rot, No. 3 is 

 the most satisfactory. This plot was sprayed seven times, namely, on 

 April 8, May 1, and May 9 for scab, and on June 12, June 27, July 

 10, and July 25 for bitter-rot, and the result was 56 bushels of sound 

 fruit and only 2 bushels of rotten fruit from the two trees, or 96.5 

 per cent of sound fruit. Plots 4, 5, and 6 each had a slightly larger 

 percentage of sound fruit, but scarcely enough to pay for the addi- 

 tional spraying which they received. However, the bitter-rot fungus 

 is so influenced by weather conditions that it is scarcely safe to follow 

 No. 3 and stop spraying as early as July 25. The treatment (eight 

 applications) given Plot 4= would doubtless be necessary in some seasons 

 to prevent both scab and bitter-rot. The results obtained in Plots 15, 

 16, and 17 seem to indicate that four applications at intervals of two 

 weeks, beo-inning June 12, June 27, or even as late as July 10, would 

 be the most satisfactory treatment, when the cost of spraying is con- 

 sidered, but as a rule it pays to give three or four treatments earlier 

 in the season for apple scab, leaf-spot, and codling moth, and, there- 

 fore, these early spring applications, combined with the early summer 

 applications, undoul)tedly give the most satisfactory results. 



The lesson to be learned from Plots 7 and S, as compared with Plot 

 6, is that the omission of the June and July applications is almost 

 fatal to the crop. Comparing Plots 7 and 8, it is seen that the one 

 extra application given to the former on July 25 resulted in a saving 

 of 28.4 per cent over the latter. Again, comparing Plots 11 and 12, 

 it is seen that one extra application given to the former on July 10 

 resulted in a saving of 33.1 percent over the latter. These results 

 emphasize the importance of spraying at the right time, and in order 

 to be sure of covering the proper tiiue the applications must be spread 

 out over a long period. 



EFFECT OF THE TREATMENT ON OTHER DISEASES. 



Seah.— It is already well known that apple scab is easily controlled 

 bj^ spraying with Bordeaux mixture. This disease was completely 

 prevented on the trees in the experimental plots receiving the three 

 early api^lications, namely, first, just before the trees bloomed; second, 

 as soon as the blossoms were shed, and third, eight days later. Some 

 scab appeared on the trees not so treated, but this variety of apple 



