68 APPLE GROWING IN CALIFORNIA. 



If apples are allowed to grow in clusters so that they are touching one 

 another the larvae not only take advantage of the ideal point of entry 

 between the apples, but the sprayer is placed at a decided disadvantage, 

 for he finds it extremely difficult to get the spray where it will be eaten 

 by the worms. Varieties that have a tendency to cluster are nearly 

 always riddled by codling moth if the pest is present in large numbers, 

 unless the clusters are broken up by thinning. 



INFLUENCE OF THINNING UPON TREES. 



As far as the trees themselves are concerned there are three main 

 reasons why thinning should be practiced : first, it allows them to make 

 a proper growth; secondly, it prevents breakage of limbs, and thirdly, 

 it induces uniform annual crops. 



A tree is capable of taking just so much plant food in the way of 

 nitrogen, potash, phosphoric acid, etc., from the soil through its roots, 

 and carbon from the air through its leaves. An excessive amount of 

 fruit is apt to require most of this food at the expense of a good thrifty 

 growth. The desire of most orchardists is to develop a tree to bearing 

 size in the shortest possible time, and to have it bear abundant crops 

 each season, often depriving it of proper growth in so doing. Our 

 trees, I fear, are too often worked to death, and we wonder why in a 

 few years ' time they begin to deteriorate and the crops of former years 

 are not harvested. The splendid deep soils so full of plant foods that 

 we find so commonly in our state, will do much towards bringing about 

 the heavy annual bearing so greatly desired, but no soil will last for- 

 ever, and the time will come when trees, or whatever else may be grown 

 on land for year after year, will develop large crops only at the expense 

 of growth and health, unless something is done in the way of fertilizing 

 to build up the soil and thinning to prevent over-bearing. 



Thinning to prevent branches from breaking down under their 

 weight of fruit is quite generally practiced, but too frequently do we 

 find the prop doing this duty. A heavy crop of apples is usually fol- 

 lowed by a light one. This is undoubtedly due to the fact that the 

 trees are allowed to bear too heavily during seasons of good crops, con- 

 sequently the formation of fruit buds for the next season's crop is 

 prevented. A tree not only has to mature its crop of fruit and make 

 a certain amount of growth during a season, but it also has to make 

 fruit buds for the succeeding season, a process which is frequently 

 rendered impossible by overproduction. 



THINNING BY PRUNING. 



The cutting out of wood containing fruit buds during the dormant 

 season may be done as the first step in thinning the crop. Pruning, 

 when done with the idea of thinning the fruit, must be done intelli- 

 gently and not by men whose only knowledge of the business consists 

 in their ability to cut off a branch because they think it interferes with 

 the proper shape of the tree. Because of no knowledge of the bearing 

 habits of an apple tree we sometimes see trees from which all the fruit 

 spurs have been cut as high above the ground as a man can reach. 

 These are exaggerated cases, but serve to illustrate the fact that too 

 little attention is paid to some of these fundamental principles which 

 1'Orir upon the subject of thinning. 



