26 



UNIV. OF N. H. AGR. EXPERIMENT STATION 



[BuUetin 221 



vase form trees is for the most part only such as is necessary to maintain 

 the different foundation branches in approximate!}^ equal and balanced 

 growth. On the semi-leader plot relatively severe pruning is necessary 

 on the central branches in order to reduce their growth and cause greater 

 development of the laterals. 



The yield for the present season is probably more closely related to 

 individual differences in the trees than to any effect of the pruning up to 

 date. One of the points of greatest interest will be the proportion of 

 different grades of fruit on the basis of color and quality which may be 

 obtained from trees pruned to different types of head. 



Fertility in the Peach Orchard {Hatch Fund) 



The winter of 1924-1925 being mild, a large number of peach buds 

 survived, and a full crop of peaches was harvested during the summer of 

 1925, The yields under the different treatments and the present diameter 

 of the trunk in inches are shown in Table XII. 



Table XII — Yields and trunk diameters in peach fertility experiment, 1925 



Plot 



1 

 2 



3 



4 



Average 

 1-2-4-5 

 Average 



1-4 

 Average 



2-5 



Treatment per 

 tree 



2 pounds nitrate of soda 



2 pounds nitrate of soda, 1 pound muriate 



of potash 



Check 



2 pounds nitrate of soda, 3 pounds acid 



phosphate 



2 pounds nitrate of soda, 1 pound muriate 



of potash, 3 pounds acid phosphate 



Nitrogen alone or in combination 



Xitrogen without potash 



Nitrogen with potash 



The results of this experiment are not so conclusive as might be de- 

 sired because of the relatively small size of the plots and because it is not 

 certain that the different plots are under perfectly similar soil conditions. 

 The treatments are not repeated on different plots, and it is therefore 

 impossible to eliminate the error due to differences in soil. 



It may be noted, however, that there is manifestly increased yield on 

 the four fertilized plots as compared to the check. While in peaches the 

 trunk diameter is not closely correlated with total size and growth of the 

 trees, there is a difference in growth in the several plots which is evident 

 to the eye and which is not expressed by the trunk diameter measure- 

 ments. The check plot and the division rows between the other plots 

 which do not receive the nitrogenous fertilizer are distinctly smaller in 

 total spread of branches than are those which receive the nitrogen. The 

 average increase in yield for the plots which received nitrogen as com- 

 pared to the check which receives none is approximately 32 pounds per 

 tree. This increased yield due to nitrogen is in substantial agreement with 



