14 UNIV. OF N. H. AGR. EXPERIMENT STATION [Bulletin 216 



Effect of Defruiting Upon the Chemical Composition and Fruit Bud Forma- 

 tion of the Apple. During the spring of 1922 Duchess apple trees were selected 

 for the purpose of studying the effect upon composition of fruit spurs of remov- 

 ing the fruit at blossom time. Three types of spurs were sampled at frequent 

 intervals throughout the season from these trees as follows: (1) spurs bearing 

 fruit from trees which had not been defruited and which bore a heavy crop of 

 fruit ; (2) spurs not bearing fruit from trees which blossomed heavily but which 

 were defruited entirely at blossom time; (3) spurs not bearing fruit from trees 

 which blossomed heavily but which had every other spur defruited at blossom 

 time. In addition the fruit from spm-s which were bearing fruit was sampled. 



During the past year the analytical work upon these samples has been 

 practically completed, in co-operation with H. R. Kraybill (Agricultural 

 Chemistry). The methods of preservation of samples and of analysis were 

 similar to those of the previous experiment. The following determinations 

 were made: moisture, free reducing substances, sucrose, soluble carbohydrates 

 hydrolyzable by weak hydrochloric acid, starch, acid hydrolyzabla material, 

 total nitrogen, total phosphorus and ash. 



In the spring of 1923 blossom counts were made upon the spurs remaining 

 upon the trees. These results show that 41.4 per cent of the spurs of the totally 

 defruited trees, 10.3 per cent of the spurs of the 50 per cent defruited trees and 

 9.2 per cent of the spurs of the non-defruited trees formed fruit buds. 



Very significant differences were found in the composition of the spurs under 

 the different treatments. The data are being tabulated and prepared for 

 publication. 



Plant Metabolism Studies. 



The work during the past year has been devoted by H. R. Kraybill and T. O. 

 Smith (Agricultural Chemistry) to making an analysis of the 22 samples of to- 

 mato tissue preserved. A modified system of Koch's method of tissue analysis 

 has been used which consists in separating the material into three fractions as 

 follows: Fi Lipoid fraction; Fs water soluble fraction and F3 water, ether and 

 80 per cent alcohol insoluble fraction. The work of making the extractions is 

 practically completed and the determination of the distribution of nitrogen, 

 phosphorus and sulphur in the respective frac-tions will be carried out during 

 the present year. 



HATCH AND STATE PROJECTS. 



Sooty Mould. Sooty mould caused a good deal of concern to apple growers in 

 1922, and in 1923 some experiments were begun by O. Butler (Botany) for the 

 purpose of studying methods of control in the Baldwin orchard of Mr. Thomas 

 Brackett at Bayside, N. H. The orchard is close to tide water and is subject 

 to fog in late summer and autumn. In 1922 sooty mould was abundant in the 

 orchard, which had never been thoroughly and systematically sprayed. In 

 1923 a number of plots were laid out and sprayed, as indicated in Table III. 

 On studying the table it wiU be noticed that the lime-sulphur and Bordeaux 

 mixture employed were used at strengths somewhat different from those in 

 common practice. The difference between 1-40 or 1^50 lime-sulphur solution 

 and the wash used is, however, less than one-tenth per cent, a difference too 



