THE MONTHLY BULLETIN 



CALIFORNIA STATE COMMISSION OF HORTICULTURE 



Vol. IlL October, 1914. No. 10. 



PRUNING THE APPLE WITH SPECIAL REFERENCE TO 



SUMMER WORK. 



By W. H. VoLCK,* Watsonville, California. 



Pruning; fruit trees has been a mneh discussed subject, both among 

 those direetly and indirectly interested in such matters. ^lany ideas or 

 notions are prevalent, especially with the practical growers. One of the 

 most general of these ideas is that a great difference in treatment is 

 necessary with the various kinds of fruit trees. According to this idea 

 some kinds are pruned heavily and regularly, and others lightly and 

 occasionally, and still others not at all. This notion about pruning is 

 one of those ideas which has developed largely as a matter of heai'say 

 and not as a result of actual experiments. We cannot point to a case 

 where all classes of fruit trees, growing under similar conditions, have 

 been pruned in different w^ays for a term of years and the results 

 weiglied and measured. 



]\ly observations lead me to conclude that had such an experiment 

 been conducted, there would be little meaning in the title of this paper. 

 That is to say, the available evidence indicates that the ultimate methods 

 of pruning will be much the same for all classes of fruit trees. It is not 

 intended to discuss such an ultimate method, obviously for the lack of 

 experimental proof, but in this paper I wish to describe certain 

 experiments with apple trees that form the basis of our present recom- 

 mendations. 



These pruning experiments are of recent date, and have not liad that 

 test of time which gives final proof, but the method evolved is in 

 harmony with all that we know regarding the successful growth of 

 trees in general. Thi.s method is, therefore, on a more substantial basis 

 than the actual duration of the experiment would seem to indicate. 



The pruning experiment was undertaken as a part of the apple 

 mildew investigation. This investigation has been in progress for a 

 numlier of years, and is jointly conducted by my office and that of the 

 Fruit Disease Investigation, United States t)epartment of Agriculture, 

 represented by ^Ir. W. S. Ballard. All statements regarding the 

 experiment refer to this investigation. 



In the fall and winter of 1912 and 1913, we began pruning a four 

 acre block of Yellow Newtown Pippins located on the C. H. Rodgers 

 place, near Watsonville. This block was one in which much experimental 

 spraying had been done and which had been turned over to us by the 

 owners of the property for such work. The trees were then about 

 twelve years old. but small for their age. due in part to the effect of a 

 previous planting of prunes which had been removed to reset w^ith 



* Address be "ore the State Fruit Growers' Convention. Davis, California, June 1 

 to 6, 1914. 



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