16 BULLETIN 1104, U. S. DEPARTMENT OF AGRICULTURE. 



A study of the data presented in Table 5 shows that there was no 

 clear-cut response to the fertilizer treatment as evidenced in the. 

 fruit. Certain observations on the effect of these fertilizers are 

 worthy of note. Each year there was a markedly higher percentage 

 of sound fruit in the nitrogen plat than in any other. The percentage 

 of bad tissue browning in the fruit from trees of this plat, however, 

 was also highest during the first season and second only to that of 

 the manure plat the second year. In checking over the individual 

 tree records on this plat, the remarkable fact has developed that 

 during each year the trees producing the highest percentage of fruit 

 which became badlj' browned were in this nitrogen plat. The foliage 

 and general appearance of these trees have been the best of those 

 under test, and generally the fruit has been either exceptionally good 

 or exceptionally bad in its tendency to brown internally. These 

 phenomena will be considered further under the subject of crop yield 

 and browning. 



The phosphate and check plats have had only a moderate percent- 

 age of browning. There has been little sound fruit, however. Gener- 

 ally, the fruit has shown traces of browning, with little entirely 

 sound and little particularly bad. 



On the whole, there has been a higher average percentage of brown- 

 ing in the manure plat than in any other. The percentage of sound 

 fruit has been low, and there has been an abundance of bad browning, 

 particularly bad core browning, in the fruit. 



In general, it may be said that the results have been negative so 

 far as causing or preventing browning through fertilizers is con- 

 cerned. The points brought out are of interest, however, particularly 

 when viewed in the light of the relationship of browning to yield, 

 discussed later in this bulletin. 



RELATION OF INTERNAL BROWNING TO THE INDIVIDUAL TREE. 



During the early investigations of this trouble it was apparent 

 that there is oftentimes a very distinct variation in the extent of 

 browning which appears during storage in fruit from different trees, 

 even when such trees are growing adjacent to each other. Conse- 

 quently, for the past six years fruit from the different trees in the 

 orchards under observation has been kept separate, and the average 

 performance records of a large number of trees over a period of 

 several years have been obtained. Only the summaries of these 

 records will be presented here. 



It was in the minds of the investigators during the first years 

 in which these records were made that the tendency of the fruit 

 to brown in storage is a tree characteristic and that certain trees 

 tended to produce fruit year after year that was inherently sound, 

 while other trees regularly produced fruit that tended to become 



