Some Grape Troubi^es of Western New York. 453 



available food supply is present in proper proportions for the use 

 of the plant. Page 426. 



12. Nitrogen apparently increases the amount o shelling. 

 Lands which are rich in this element of plant food seem to suffer 

 more than those growing in land that makes a smaller growth of 

 wood. Page 427. 



13. The shelling of grapes upon soils rich in nitrogen is pro- 

 pably not due to an inherent tendency of the nitrogenous food to 

 produce shelling, but rather to a faulty ratio between the amounts 

 of available plant food. Page 427. 



14. The kind of soil, not considering the food supply con- 

 tained in it, does not appear to exercise any marked influence 

 upon the degree of shelling. Page 427. 



15. Too much cultivation seems to aggravate the trouble, 

 probably on account of the larger amount of nitrogenous food 

 liberated by the operation. Page 427. 



16. Excessive drought alone cannot be held as the sole cause of 

 the trouble, although it is probable that the dry weather caused 

 the loss to be greater than it would otherwise have been. Page 428. 



17. Excessive rains after a prolonged drought may have influ- 

 enced the severity of the shelling but to what extent is not 

 known. Page 429. 



18. A weak root system would have an effect upon a plant 

 similar to that exercised by allowing it to overbear, and a like 

 tendency towards shelling would exist. It seems probable from 

 the fact that young vines, as a rule, shell the most, that the lim- 

 ited root system may be in part responsible for the trouble. 

 Page 429. 



19. A want of barnyard manure has been ascribed as a cause, 

 and the trouble, in one case, has been stopped by its use. Page 431. 



20. No evidence at hand goes to show that shelling is due to 

 a want of phosphoric acid. Page 431. 



21. Many vineyardists have apparently stopped the shelling 

 by applications of potash. Page 431. 



22. Potash seems to be the food required by the plant in the 

 majority of the cases in which the vines shell and it may be 

 wanted in all cases. Page 432. 



23. The principal reason for this lack of potash is undoubt- 



