CULTIVATION OP THE QBAPB UNDEB GLASS. 155 



DISEASES OF VINES. 



Shanking. — This formidable disease has been a fruitful 

 theme of conjecture, and many reasons have been assigned for its 

 cause, and as many remedies propounded. It makes its appear- 

 ance just as the grapes are changing from their acid to their 

 saccharine state, arrests this transformation, the berry remaining 

 acid, and becoming in a short time shrivelled. The little stem 

 or shank, which attaches the berry to the bunch, decays, which 

 is all the functional derangement apparent to the eye, hence the 

 term shanking, applied to the disease. 



It is probable that several causes may combine in the pro- 

 duction of this disease; prominent among these are over-cropping, 

 injury to the foliage by red spider, or other cause, the roots 

 of the vine having penetrated into a cold, wet subsoil, or the 

 roots having made a late, succulent growth, by reason of the 

 border being too rich and damp, and perhaps too plentifully sup- 

 plied with manure water. These causes may not aU exist at any 

 one time, but some one or more of them will be found to have 

 just so far enfeebled the vine as to make its loss of vigor apparent 

 in tliis way, when in nothing else does it seem to manifest any 

 lack of healthy action. The trouble is thought by the ablest 

 gardeners to be owing to the want of weU ripened, iine and 

 woody roots at the time when winter sets in, roots that are 

 ripened to their extremest points. If instead of being thus ripened, 

 they are from any cause coarse and soft, with a spongy texture, 

 when winter sets in, all these spongy fibres will die and decay 

 during the winter, back to the main stem roots, from which they 

 issued. When the vines start to grow again the main roots 

 throw out young fibrous rootlets to supply their place ; but these 

 are unable to supply the vine with sufficient nutriment to sup- 

 port both the requisite wood and fruit, hence the shanking of 

 the firuit, while the other functions of the vine seem to be per- 

 fonned in a healthy manner. If it be certain that the shanking, 



