February, 1929] agricultural experiments 1928 13 



are decidedly biennial in bloom it is probable tbat the fluctuation over a 

 series of years would not be as great as these reported in this, the first 

 season in which complete data were taken. 



Chemistry of Fruit Bud Formation 



An extensive investig^ation of the chemical constituents of fruit spurs 

 has been conducted by G. F. Potter and T. G. Phillips. Spurs were stud- 

 ied from 26 different plots of Baldwin trees which showed a considerable 

 variation in fruit bud formation, rangin,^ from about 2 percent to practically 

 60 percent. The analyses for dry matter, soluble and insoluble solids, 

 reducing sugar, sucrose, phlorizin, starch, acid hydrolyzable material, 

 soluble and insoluble nitrogen, were studied statistically to determine the 

 constancy of the relation between the amount of each substance present and 

 the proportion of spurs forming flowers. The results indicate that a pri- 

 mary relation with fruit bud formation could be established only with the 

 size of the spur as measured by dry weight or soluble and insoluble solids 

 and with the percentage of nitrogen present soluble, insoluble, or total. 



Work completed by L. R. Tucker this year indicates that with Baldwin 

 apple trees growing under New Hampshire conditions, the greatest terminal 

 twig growth is made during the year when the tree or branch is bearing 

 fruit. In classifying the growth of 1,000 branches, it was found that bear- 

 ing branches from bearing trees made the greatest terminal growth. Non- 

 bearing branches on trees which had fruit on other branches made the next 

 best growth, and the least growth was made by the branches on non-bearing 

 trees. Fruit bud formation, however, is in the reverse proportion, being 

 greatest on the non-bearing trees, next greatest on the non-bearing limbs of 

 the bearing trees, and practically absent in the case of bearing limbs on 

 bearing trees. (Adams Fund.) 



FINDING THE VALUE OF THINNING APPLES 



A study of the eflFect of thinning on the size and market value of the fruit 

 and crop of Baldwin ayjples was started by H. A. Rollins. Pairs of trees, 

 similar in size, set of fruit, and growing under the same soil conditions, 

 were selected. One tree of each pair was thinned and the other not. Five 

 such pairs of trees were used in 1928 in each of four orchards in different 

 localities in southern New Hampshire. At harvest time eight random 

 samples of 25 apples each were picked from each tree, from high and low 

 positions, on the east, west, north, and south sides of the tree. The diam- 

 eter of each one of the 200 apples from each tree was accurately measured, 

 the percentage of the colored surface estimated, and a record made of all 

 types of defects and blemishes. 



The records show that the size of the fruit and the amount of color is 

 increased by thinning, but these benefits were accompanied by a decrease in 

 the total crop, which in large measure affects the benefits. On a percentage 

 basis the fruit from the thinned trees appeared much better than the fruit 

 of the unthinned. Thinned trees showed a considerably higher proportion 

 of fruit of the large sizes. However, when this is calculated to the total 

 number of pounds of fruit of each size on the tree, the thinning was not a 

 paying proposition. The thinned fruit was superior in color and freedom 

 from blemishes, but probably not enough to affect the results to any marked 



