EXPERIMENT STATION BULLETINS. 



445 



EXPp]RIMENT AT FENNVILLE. 



Further work with pears to compare dusting with spraying was conducted 

 in the P. H. Broe orchard at Fennville. The trees in this orchard are mature 

 and are of several varieties. Although all varieties were dusted or sprayed 

 aUke, the Bartlett was the only one considered in the results. 



Materials and applications. The experiment started with the pink or 

 cluster apphcation; both plots having received a "pre-pink" (or delayed 

 dormant) application of lime-sulphur, 6^-50, for pear psylla control. This 

 spray was undoubtedly of great value for the control of scab this year, as 

 weather conditions very favorable for scab development prevailed during 

 the period when the buds were expanding. No check plot was left because 

 of the necessity to spray for pear psylla. 



Three other applications for scab control were made after the "pre-pink" 

 stage. 



1st. When buds had separated in the clusters. 



2nd. Calyx apphcation. 



3rd. Two weeks after second application. 



For the first application sulphur alone was used on the dusted plot and 

 bordeaux mixture on the sprayed plot. For the calyx application Niagara 

 "All-in-One Mixture", containing sulphur, lead arsenate and nicotine sul- 

 phate was used on the dusted plot and on the sprayed plot lime-sulphur, 

 1 to 40, lead arsenate and Black Leaf 40 were used. For the third application 

 90-10 sulphur-lead dust and bordeaux mixture with lead arsenate were used. 

 The dusted plot received an apphcation of "All-in-One Mixture" on July 8 

 for pear psylla but the sulphur and lead arsenate in it was undoubtedly 

 beneficial for the control of scab and worms. 



RESULTS. 



Scab control. When the fruit was picked, the crop from three dusted 

 trees and three sprayed trees was sorted and counted with the results shown 

 in table 8. 



The percentage of scab on the fruit from both plots was very low and 

 practically all the scab was in very small spots. There were only two or 

 three pears in each lot which were badly scabbed. When comparing these 

 results the fact that both plots received a "pre-pink" application of lime- 

 sulphur spray must be considered. This early application, as stated above, 

 was probably very important in the control of scab this season, as the period 

 when the buds were expanding was the only time during the season when 

 weather conditions were really favorable for scab development. 



