March, 1938] Agricultural Research in N. H. 11 



However, the outside rows which had had no crop during the season 

 preceding the fertilization showed no injury whatever. It is quite pos- 

 sible that only trees which have borne heavily during the preceding 

 season are susceptible to this injury. The work has been in charge of 

 G. F. Potter, W. W. Smith and M. A. Tingley. Chemical studies have 

 been made by T. G. Phillips of samples taken at intervals during the 

 winter from the roots, trunk, and branches of trees which had been 

 heavily fertilized and of their non-fertilized controls. There appears 

 to be a distinctly higher concentration of soluble nitrogen in the roots 

 of fall fertilized than of control trees. Samples from the trunk and 

 branches seem to show no consistent differences due to the fertilizer 

 treatment. {Adams Fund) 



Studies in Blossom Bud Formation 



Four or five per cent, more spurs blossomed last spring in the apple 

 plots sprayed throughout the season with mild sulphur than on the 

 plot sprayed with lime sulphur solution in 1934. This rather small 

 difference is the first observed, reports G. F. Potter. Since the forma- 

 tion of blossoms is conditioned rather early in the season, those formed 

 in 1934, the first year of the experiment, may not have been influenced 

 by the treatments. Owing to a pronounced biennial bearing tendency, 

 practically none were formed in any plot in 1935. The blossoms open- 

 ing this season were formed in 1936, and may well be the first that 

 could show a response to the spraying. 



The percentage of blossoms setting fruit in 1937 was very markedly 

 influenced by the spray treatment, being 10 to 20 per cent, higher on 

 the mild sulphur plots. In spite of the heavy set the apples grew as 

 large as on the lime sulphur plots, and, in consequence, the crop was 

 much heavier. This circumstance of heavy set and heavy crop will 

 have a tendency this season to reduce fruit bud formation for next year 

 on these trees. The leaf area was measured in midseason. There were 

 13 to 14 square inches per spur on the mild sulphur plot and less than 9 

 on the lime sulphur. This very significant difference may be due in part 

 to injury to the foliage which occurred this year and in part to higher 

 reserves of food stored in the tree from the previous season. 



Some trees of Northern Spy are also included in this block and re- 

 ceive the same treatments as the Mcintosh. Unfortunately, time did 

 not permit making a fruit spur count. Yield records indicate that, 

 both this season and as an average for the seasons of 1936 and 1937, the 

 trees sprayed with mild sulphur have been more productive than those 

 sprayed with lime sulphur. The differences are striking and of strong 

 statistical significance. {Adams Fund) 



Relation of Thinning to Blossom Bud Formation 



Further observations were made this season by G. F. Potter on the 

 Mcintosh trees in which biennial bearing had been overcome in 1936 by 

 thinning the fruit early in 1935. (Potter. Proc. A. S. H. S. 34:139) 

 The trees thinned in 1935 bore a good crop in 1936, while those not 

 thinned had practically no fruit. Nevertheless, blossom bud forma- 

 tion on these plots differed by only a small amount — much too small to 



