148 Repokt of the Department of Botany of the 



and his associates, J. G. Grossenbacher and W. 0. Gloyer. To 

 Mr. Grossenbacher, in particular, the writer is under obligation 

 for much valuable assistance. The number of summer primings 

 varied from two to six in different seasons. At each pruning 

 every plant on plats II, IV and VI was carefully examined and 

 all dead or dying canes cut out, carried away and burned. In 

 the removal of diseased canes an attempt was made to cut low 

 enough to remove all of the fungus. It will be shown later that 

 this was sometimes found difficult to accomplish. 



A brief account of each year's work on the experiment will now 

 be given. 



FIRST SEASON. 



During the first season of the experiment (1907) the three 

 treated plats (II, IV and VI) were summer pruned six times on 

 the following dates: May 20, June 10 and 26, July 17, August 

 16 and September 20. The small size of the plants at this time 

 made it practicable for a man to cover two rows at each passage 

 through the field. The primings were placed in small piles be- 

 tween the rows and afterward carried out to the ends of the rows 

 and burned. In the first pruning there were found large numbers 

 of canes of the previous season's growth with 4 to 10 inches of 

 their upper portion dead and without leaves. Some of these may 

 have died from other causes than necrosis, but all were carefully 

 cut out. Frequently, the pith was discolored for a distance of 

 several inches below the lowest point of wood discoloration. In 

 some cases this necessitated the removal of living branches. 



SECOND SEASON. 



In 1908 four primings were made as follows: June 2 and 26, 

 July 31 and August 21. The first priming of this season should 

 have been made earlier as the new shoots were so long (12 to 14 

 inches) that they hid the dead branches. Fifty dead canes were 

 removed in the first pruning and 46 in the second. In the third 

 pruning Mr. Grossenbacher noted 198 new cane infections and 

 49 old ones besides numerous leaf infections. In the fourth prim- 



