STATE POMOLOGICAL SOCIETY. 6l 



my experience, I have found that winter-kilHng of fruit buds 

 has a more direct correlation with soil moisture, air drainage, 

 and humidity, than it has with the plant food supply. In the 

 peach there is a decided delaying of maturity of fruit by the use 

 of nitrogen. By the skilful handling of nitrate of soda as a 

 fertilizer one may be able to delay the normal ripening period 

 of this fruit from a week to ten days. Stewart had similar 

 results with the apple. It is possible, however, that delayed ma- 

 turity may be accounted for by the decrease in the amount 

 of sunlight reaching the fruit, due to the excessive growth of 

 foliage caused by the nitrogen in the fertilizer. One would 

 expect that heavy applications of nitrogen would give an in- 

 creased size to the fruit, but this does not appear to be so. On 

 the contrary, we have found in peaches and Stewart has found 

 in apples that heavy applications of mineral nitrogenous fer- 

 tilizers tend to decrease the average size of the fruit. In the 

 case of the use of barnyard manure this is not the fact; on the 

 contrary, the size of the fruit is increased. This increase is 

 probably due directly to the influence of the humus which barn- 

 yard manure forms in the soil, thus increasing the soil's water- 

 holding capacity. Soil moisture probably has more to do with 

 size of fruit than any other single factor. 



Trees heavily fertilized with nitrogen, usually produce fruit 

 that is deficient in color. The heavy growth of foliage shades 

 the fruit to such an extent that the proper colors of the fruit 

 fail to develop. It has been pretty conclusively proven that 

 color is more dependent upon sunlight than upon any other 

 factor. In fact, it may be possible that sunlight is the only factor 

 concerned in producing color. It has also been our experience 

 that, contrary to common belief, nitrogenous fertilizers are a 

 great aid to a heavy set of fruit buds. In our work with peaches 

 the trees most heavily fertilized with nitrogen have produced 

 the greatest number of fruits, thus showing that growth and fruit 

 production are not necessarily antagonistic functions of plants. 

 It is probably true, however, that heavy excesses of nitrogen do 

 seriously interfere with fruit production. The soil moisture is 

 here again a most important factor. Decreased or delayed fruit 

 production in orchards heavily fertilized with barnyard manure 

 is probably due more to the addition of humus to the soil, thus 

 increasing its water-holding capacity, than to the nitrogen in 

 the manure. 



