FERTILIZERS AND MANURES FOR THE ORCHARD 185 



lem should be viewed without prejudice from the stand- 

 point of discovering any limiting factor to maximum results. 

 If insufficient plant-food is available, this situation should 

 be sensed as soon as possible and the condition relieved. 

 It will depend, however, on the kind of trees, the soil, the 

 system of culture followed, the age of the trees, and finally 

 on the results of these conditions as manifested in the trees 

 themselves. This is not so unsatisfactory as it at first seems. 

 An experienced grower should have a sufficiently accurate 

 knowledge of what the possibilities of trees are, to determine 

 whether they need additional fertility. In general, the 

 stone-fruits, particular^ the peach, should be fertilized 

 each year after they come into bearing. The apple and pear, 

 when grown in the sod or mulch system, should usually be 

 fertilized. However, exceptions will present themselves; and 

 when these fruits are well tilled they may continue for many 

 years without need for additional plant-food materials, unless 

 they are inter-cropped. When trees are nob making an av- 

 erage terminal growth of at least several inches (6 to 12), 

 when the foliage is not a rich green color and held well into 

 the fall, and when they are not bearing good crops practi- 

 cally every year, it would be well to introduce additional 

 fertility either in the form of artificial fertilizers or manures 

 or both. However, the varietal factor enters here strongly; 

 also it should be determined whether the orchard is well 

 drained and free from other conditions known to be inju- 

 rious. All this, of course, means that in the case of doubt the 

 only definite answer can be obtained by the local test. If 

 a response is secured by any of the fertilizer elements or a 

 combination of them, their use should at once be extended 

 to the remainder of the orchard. Under many conditions, 

 very large financial returns may be secured from the use of 

 fertilizers; it is not wise to delay applying them until such 

 marked results are secured as on some of the impoverished 



