Jan., 1924] PROGRESS OF AGRICULTURAL EXPERIMENTS 1 1 



in co-operation with H. R. Kraybill (Agricultural Chemistry). Practically all 

 of the work on the fruit spurs which were sampled dm'ing the year of 1921 has 

 been completed and this phase of the project is nearly ready for publication. 



During the period of most active fruit bud formation, the spurs on the non- 

 fruiting sod plats, 10 per cent of which formed fruit buds, were lowest in total 

 nitrogen; those of the fruiting sod plats, none of which formed fruit buds, and 

 those of the non-fruiting nitrate plats, 44 per cent of which formed fruit buds, 

 were medium in total nitrogen ; and those of the fruiting nitrate plats, one-half 

 of one per cent of which formed fruit buds, were highest in total nitrogen. At 

 this same time the spurs from the non-fruiting sod plats were highest in starch; 

 those from the non-fruiting nitrate plats, medium in starch; and those from 

 the fruiting sod plats and the fruiting nitrate plats were lowest in starch. 



It has been believed that a condition of liigh starch and low nitrogen content 

 of the spurs during the time of fruit bud formation is essential for fruit bud 

 formation. Apparently other conditions are necessary also, since the non- 

 fruiting nitrate plat spurs, which had about the same total nitrogen content as 

 the non-fruiting sod plat spurs, were lower in starch and produced about 44 

 per cent of fruit buds, while those of the sod plats produced only 10 per cent. 

 An examination of the starch and total nitrogen analyses for the entii'e season 

 shows that the spurs from the trees grown in sod are in general lower in total 

 nitrogen and higher in carbohydrates than the spurs from the trees growai on 

 the nitrate plats. 



Effect of Defruiting upon Chemical Composition and Fruit Bud Formation. 



During the season of 1922 the fruit spur composition project was carried on 

 using fruit spurs from Duchess trees in the Thompson Orchard. In this expcri- . 

 ment it was planned to base the investigation upon the known fact that if a 

 fruit spur is deflorated at about the time the blossoms open or when they are 

 in the pink bud stage, it will usually form flower primordia the same season; 

 whereas, if the blossoms are allowed to remain upon the fruit spur and fruit is 

 allowed to set, it is extremely rare for flower bud formation to take place. 

 Three Duchess trees on which practically every fruit spur was carrying bloom 

 were completely deflorated just prior to the opening of the blossoms. Check 

 trees were allowed to set a full crop of fruit. 



From two other similar trees a sufficient number of blossoms were removed 

 so that every second spur bore fruit. The object of this experiment was to 

 test whether or not the fruit spur acts as an independent unit. Far-reaching 

 conclusions with reference to the feasibihty of overcoming the well-known 

 biennial habit of apple trees have been drawn by certain authorities on the 

 basis that each fruit spur acts independently of the other fruit spurs on the 

 tree. If this were true, one would expect the 50 per cent of the fruit spurs 

 which were deflorated to produce as high a percentage of bloom as those fruit 

 spurs on the trees in which all of the spiirs were deflorated. In other words, 

 the object of the experiment was to test whether or not the apples remaining 

 upon 50 per cent of the spurs on the tree would prevent fruit bud formation on 

 deflorated spurs on the same tree. In the spring of 1923 counts were, made on 

 the fruit bud formation of these trees and the results are given in Table 1. 



