340 



PRINCIPLES AND PRACTICE OF PRUNING 



to the stake. In this case it may break off at the bottom, or at least 

 will form an awkward crook near the ground when it matures. In 

 either case it is difficult to form a good trunk the following year. 

 Even when the ties do not break, the cane will not be well suited 

 for the commencement of a trunk, as the joints will be so long that 

 it will be impossible to leave enough well-placed buds at the winter 

 pruning. 



Both these difficulties are avoided by timelY topping. When such 

 vigorously growing canes have grown 12 or 18 inches above the top 

 of the stake they are cut back about level with the stake. This is 

 most conveniently done with a long-bladed knife or a piece of split 

 bamboo. After topping, the cane ceases to grow in length and 

 laterals start at most of the joints. It is less 

 exposed to the action of the wind and the laterals 

 supply the buds needed for forming the vine at 

 the winter pruning. 



The result of the second season's growth, 

 then, is to produce a single vigorous cane 

 with or without laterals. This is the cane which 

 is to develop into the permanent trunk of the 

 vine. It must not only be large and vigorous, 

 but must be properly matured. If the vine is 

 allowed to grow too late in the season, an early 

 frost may destroy the unmatured cane and much 

 of the results of the year's growth will be wasted. 

 Such a frost may indeed kill the entire vine. 

 Grafted vines are particularly liable to injury 

 from this cause, as if they are killed down to the 

 union they are completely ruined. Ungrafted 

 vines when killed to the ground may be renewed 

 from a sucker next year. This sucker, however, 

 is likely to grow with such vigor that it is even 

 more liable to injury from an autumn frost than 

 the original shoot. 



This late growth is much more likely to occur 

 with young vines than with old. The old vines 

 stop growing earlier because their energies are 

 directed into the crop, and as they produce a 

 larger amount of foliage they draw more upon 

 the moisture of the soil, which therefore dries 

 out earlier. 



If possible, late growth of the young vines must be prevented 

 and the wood matured before frost. This is accomplished by means 

 which promote the drying of the soil in autumn. Late irrigations 

 should be avoided. Cultivation should usually stop by midsummer. 

 In very moist, rich soils it is often an advantage to grow corn, sun- 

 flowers or similar crops between the rows of vines to take ofT the 

 surplus moisture. In some cases it is good practice to let the sum- 

 mer weeds grow for the same purpose. 



FIG. 285 



GRAPE SPUR 



Letters and lines 



indicate positions 



of good and bad 



cuts (253). 



