Jan., 1924] PROGRESS OF AGRICULTURAL EXPERIMENTS 



23 



the practice of applying nitrate of soda to strawberry plants is not an uncom- 

 mon one in New Hampshire. The results of this experiment being computed 

 from the average of four different plots should be fairly accurate and should 

 indicate a benefit from the practice, if any such existed. 



During and just prior to the fruiting season, differences in the color of the 

 various plots could be distinguished, those which received nitrate being darker 

 green than those which received none. Samples were taken of one hundred 

 leaves chosen at random from the nitrate plots and from the check plots. It 

 was found that the area of the leaves from the high nitrate plots averaged 6.8 

 square inches, while on the check plots the average area of leaf was 5.8 square 

 inches. 



A similar experiment has been outlined on a strawberry bed which will fruit 

 in 1924. Applications of nitrate made at intervals throughout the growing 

 season will be compared with similar applications of acid phosphate and with 

 apphcations of nitrate in the fall. 



Observations were made on August 3 on the number of runners which had 

 formed in proportion to the mother plants. Only two plots had received 

 fertilizer prior to August 3, namely: the plot in which nitrate of soda was used 

 at three different times during the growing season, and the plot in which acid 

 phosphate is'appHed in a similar way. The number of runners per mother 

 plant was found to be 1.21 on the plots which had received nitrate, 1.00 on 

 the plot which had received phosphorus, and 1.25 and 0.9 respectively, on the 

 plots which had received no fertilizer. It is apparent that there were no signif- 

 icant differences in the number of runners due to the effect of fertilizers. A 

 number of strawberry crowns have been preserved in fixing solution for micro- 

 scopical examination to study the time of fruit bud formation in the straw- 

 berry in New Hampshire. 



Pruning Experiment with Apples. 



The type of head "pruning experiment has been carried on exactly as in 

 previous seasons. The trees have now completed the fourth season of growt,h, 

 and the semi-leader trees have all of the foundation branches which they are 

 expected to carry permanently. From this date the leaders will be suppressed. 

 The usual records have been taken on the amount of wood removed in pruning. 

 Owing to the increase in size of the trees it is no longer feasible to measure the 

 length of the twigs removed, but the branches have been weighed. Measure- 

 ments of the increase in trunk diameter have also been made as an index of 

 total growth of the trees. The data are given in Table V. 



T.VBLE V. — Data on type of head pruning experiment. 



