FIFTY-FIRST A>fNUAL REPORT. 27 



gen alone set very much heavier crops than the check, but apparently 

 not quite as heavy as phosphate plots. I think these statements will be 

 borne out later when yield data is presented. If phosphorus has been 

 responsible for increasing the set this will be the first recorded case that 

 I know of. 



Throughout the past season there were distinct differences between 

 the foliage of the various plots. The leaves of all plots receiving nitro- 

 gen alone or in combination, or of all plots except the check and acid 

 phosphate ones, were more numerous, larger and decidedly darker green 

 in color. The trees of the complete fertilizer, the sulphate of ammonia 

 and nitrate of soda plots were dense and one could not easily see through 

 them while the acid phosphate and check plot trees were open and had 

 sparse, light green foliage. 



Differences in growth were recognized early in the season and became 

 more marked as the season advanced. During the last week in August, 

 twigs representative of the longer growths of each plot were collected 

 and mounted to show differences of growth. These may be seen in the 

 room adjacent to this one. The average length of these twigs are as 

 follows : 



Sulphate of ammonia 8 inches 



Nitrate of soda 6.5 inches 



Check 2.9 inches 



Acid phosphate 2.9 inches 



Complete fertilizer 9.8 inches 



Acid phosphate and sulphate of ammonia (1 yr.) 5.1 inches 



It is noted that all plots receivi,ng nitrogen gave decidedly increased 

 twig growth. Phosphorus may have been responsible for some of the 

 increased growth in combination plots. Its failure to produce increased 

 growth where used singly may be due to its inability to give such response 

 or to the fact that the heavier setting of fruit taxed the trees to their 

 capacity and that yield was at the expense of twig growth. 



Dust failed to hold the scab in check in this orchard for some unknown 

 reason and this affords an excellent opportunity to compare plots for 

 disease resistance. Fortunately the duster was driven cross-wise of the 

 plots at each application and there appears no reason why one plot 

 should not have produced as clean fruit as another, barring the effects 

 of fertilizers. 



During early summer it was noticed that the fruit in the complete 

 fertilizer plot had less scab than the orchard as a whole. Closer observa- 

 tion throughout the season and during harvest showed marked differ- 

 ences between the complete fertilizer plot on the one hand and the check 

 and acid phosphate plots on the other. It would seem then that in 

 this orchard stimulation by fertilization has aided in controlling scab 

 or has made the fruit more resistant to disease attacks. 



The fruit was handpicked, run over a Gift'ord Sizer to get an idea as 

 to the effect of fertilizers in influencing size of fruits and then weighed. 

 The fruit was sized into four grades: less than two inches, two to two 

 and one-fourth inches, two and one-fourth to two and one-half inches, 

 and larger than two and one-half inches. For our purposes we will 

 combine the first two sizes. The average yield of handpicked apples 

 in pounds per tree is given below. 



