CHAPTER XXIV 



PRUNING— THE SEASON 



The subject of pruning has been shown to present three major aspects, 

 one of which is a consideration of the varying response from pruning at 

 different seasons. Theoretically at least this involves a study of the 

 different effects from pruning each successive month, or perhaps at more 

 frequent intervals. Practically the question is much less complicated, 

 involving principally a comparison of the effects attending pruning during 

 the growing season with those following winter pruning. 



Pruning at Different Times During the Dormant Season. — Prun- 

 ing at different times during the dormant period may, however, re- 

 ceive brief consideration. Dormant or winter pruning is generally 

 understood to mean late winter or early spring pruning, since it is usually 

 done then. Winter pruning, however, may begin as soon as the plants 

 become more or less dormant in the fall and may continue into the spring 

 until vegetation is starting actively. The supposed advantages and 

 disadvantages of pruning at different times during the dormant period 

 have been long discussed. Apparently so far as any effect on the amount 

 and character of subsequent growth is concerned there is little or no 

 difference. This is brought out clearly by experimental work with apples 

 in England* and in Minnesota^ and with grapes in New York.^* On the 

 other hand since there is a gradual translocation of food materials from the 

 canes to the trunk and roots of the grape during a 3- or 4-weeks period 

 following leaf fall,"*^ pruning before this translocation is complete or after 

 the reverse movement has begun in the spring should result in a some- 

 what greater check to vigorous growth of the vine than a corresponding 

 pruning during the period between these extremes. This effect has 

 been noted both in France*" and in California.^ 



In California the time of winter pruning has been found to be impor- 

 tant in determining when grape vines of. the Vinifera group start growth. 

 Vines pruned immediately after the fall of the leaves started earliest; 

 those pruned in midwinter started about 4 days later and those pruned 

 considerably later, when bleeding commenced, were delayed about 6 days. 

 "Pruning when the terminal buds commenced to swell retarded the 

 lower buds 11 days, and, when the terminal buds had grown 2 or 3 inches, 

 20 days."^ In other words the lateness of starting of the buds was in 

 the order of the lateness of the pruning. 



In commenting on some of the practical applications of these facts in grape 

 culture in California Bioletti'' remarks: "The retardation of the starting of the 



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