24 N. H. AGR. EXPERIMENT STATION [Bulletin 212 



There appear to be no significant differences in either the amount of wood 

 removed in pruning or the growth of the trees. In most experiments the un- 

 pruned trees have been found to make a greater growth than those which have 

 been pruned. In this experiment only a small number of trees have been 

 left unpruned, and all of these, unfortunateh', are unfavorably located with 

 reference to soil and moisture conditions. The data from these unpruned 

 trees are probably not of any significance. 



Fertility in the Peach Orchard. 



A crop of peaches was harvested in this orchard for the first time during the 

 season of 1923. The average yields for the various plots, which include the 

 Belle of Georgia, J. H. Hale, and Elberta varieties, were as follows: 



Plot 1. (Treatment: 200 lbs. Nitrate of Soda per acre), 3.7±0.5 baskets. 

 Plot 2. (Treatment: 200 lbs. Nitrate of Soda, 120 lbs. Muriate of Potash), 



6.5±0.4 baskets. 

 Plot 3. (Check), 2.9±0.3 baskets. 

 Plot 4. (Treatment: 200 lbs. Nitrate of Soda, 350 lbs. Acid Phosphate), 



1.9±0.3 baskets. 

 Plot 5. (Treatment: 200 lbs. Nitrate of Soda, 350 lbs. Acid Phosphate, 120 



lbs. Muriate of Potash), 3.9±0.6 baskets. 



Close study of the orchard raises some question as to whether or not the plots 

 on the northwest side are as favorably located as those in the central and 

 eastern sides of the orchard. This diflficulty common to all single plot experi- 

 ments may vitiate the yield records on each specific treatment. However, 

 the average yield of the plots which receive nitrogen was 4.0 baskets as com- 

 pared to 2.9 baskets on the check. Records of diameter increase have also 

 been made on this orchard and correspond to the differences in yield, in that 

 growth has been greater on the trees receiving nitrogen. 



Plant Breeding. 



Sweet corn breeding which was begun under this project was not studied 

 during the season of 1923. The seed is on hand and wUl be planted in 1924. 



Maintenance of Soil Fertility in the Garden. 



The son fertility plots were planted by J. R. Hepler (Horticulture) to pota- 

 toes in 1923. The seed used was certified seed from New Brunswick, and there 

 was no leaf curl or mosaic disease to limit the crop. On Plots 3 and 7, rye was 

 sown in the fall of 1922 for a green manure crop. The plots are approximately 

 seven-eighths acre in size, half of which is treated with 2000 pounds of lime 

 every second year. All told, about 6000 pounds of lime have been applied, or 

 just about the requirement for these plots. 



Plots 5 and 7 dropped so low in yield in 1922 that an application of eight 

 tons of manm-e per acre was made on them. This is the only fertilizer these 

 plots have received since 1919. 



The effect of chemicals on potatoes is shown by comparing Plots 1 and 5, 

 which received only manure, with Plots 2, 4, and 6. Plot 1 received 32 tons, 

 and Plot 5, 8 tons per acre. The manure plus fertilizer plots, 2, 4 and 6, showed 



