THE MONTHLY BULLETIN. 175 



Influence of Thinning Upon Trees. 



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

 reasons why thinning should be practiced : tirst, 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 being deprived of proper growth in so doing. Our 

 trees, I fear, are too often w^orked to death and we wonder why in a few 

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

 not har\'ested. 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 forever, 

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

 land for year after year Avill 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 overbearing. 



Thinning to prevent branches from breaking down under their 

 weight of fruit is quite generally practiced, but more generally do we 

 find tlie prop doing this duty. Some of the best horticulturists of our 

 land have claimed that props have no place in the orchard, and are 

 indicative of improper methods of pruning and thinning. While with 

 only a very limited experience in the State it would be hasty to condemn 

 such a practice, yet the system is open to criticism. If proper pruning 

 and thinning will do away with the use of these unsightly and unhandy 

 appliances, and also relieve the trees of too heavy a burden, then by 

 all means the pruning and thinning shears should be brought into more 

 general and more intelligent iLse. 



In the case of apples at least a heavy crop is usually followed 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, consecpiently 

 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 impos- 

 sible by overproduction. There is experimental evidence which goes to 

 prove that this is also true in the case of peaches. Professor C. P. 

 Close, in the Delaware State Keport of 1902, comments upon results 

 he attained in thinning Elberta peaches, as follows : 



"The writer has conducted a number of experiments in thinning 

 peaches, plums and apricots and has gotten most favorable results. 

 These favorable results have not only been marked in the year in 

 which the thinning was done, but also in the two following seasons 

 at least. There has been an influence which caused the thinned 

 trees to set a good load of uniformity distributed fruit, while 

 adjoined unthinned trees set either an excessively heavy or a very 



