FERTILIZERS, OTHER THAN NITROGENOUS 227 



are generally too poorly suited to fruit production, even with the aid of 

 such palliative measures as liming. 



Season for Applying Fertilizers. — Comparatively few data are avail- 

 able upon which to base a decision as to the best time for appl^ang 

 fertilizers of different kinds in the orchard. Without doubt many factors 

 have a bearing in this connection. Among the more important may be 

 mentioned: the varying states or conditions of the plant as the season 

 advances, the changing nutrient value of the soil, moisture supply includ- 

 ing the possibihty of losses from leaching and bacterial activities of differ- 

 ent kinds. It is only as these are understood and properly evaluated in 

 each individual case that fertilizer applications can be timed to best 

 advantage. When easily soluble nitrogenous fertilizers are required 

 large amounts should not be put on in the fall, during the winter or too 

 early in the spring, on account of the danger of leaching. Indeed, this 

 is always a prime consideration in making nitrogen applications, though 

 relatively unimportant with other fertilizers. On the other hand, 

 fertilizers carrying nitrogen in organic combination must be applied 

 sufficiently early to give disintegration processes time for making 

 the nitrogen available to the plants before it is too late for them to 

 absorb it. 



Frequent observation and experience indicate that orchard fruits 

 respond very quickly to easily soluble nitrogenous fertilizers such as 

 nitrate of soda and sulphate of ammonia, when these are made as growth 

 is starting in the spring or later during the growing season. Thus 

 Ballou^ reports a greatly increased set of fruit in weak, devitalized apple 

 trees when nitrate of soda was applied just before the opening of the 

 flowers. In this case not more than 3 weeks had elapsed before it was 

 clearly evident that the trees were receiving benefit from the application. 

 In fact this immediate effect of quickly available nitrogen has led to the 

 general practice of applying it just as growth is starting and it would 

 seem that experience bears out the wisdom of so timing nitrate appli- 

 cations. On the other hand, when nitrogen is needed, not so much for 

 aiding the setting of fruit or perhaps for increasing the vegetative growth 

 made during the early part of the current season — this latter being an 

 influence which, as yet, has not been very accurately determined — but 

 rather for its effects the following season, through organic products 

 elaborated during the summer and fall months and stored through the 

 winter, the best time for fertilizer apphcations may be quite different. 



Some evidence in support of this last suggestion is furnished by experi- 

 mental work in England. ^^ Apphcations of quickly available fertihzers 

 to orchard trees of a number of varieties in August, supplemented by 

 applications in the spring at the time of fruit setting, caused trees to bear 

 annual crops. The immediate effect of the midsunnner applications is 

 to cause the trees to hold their foliage later in the fall, thus accumulating 



