452 Bulletin 76. 



and render it worthless. Apply with a cloth swab, and only to 

 dormant plants. 



SUMMARY.* 

 Part I. 



1 . The shelling of grapes occurred to a very serious extent in 

 1890 and 1894. Page 418. 



2. This disease is probably not identical with apoplexie or with 

 rougeot, two diseases occasionally present in French vineyards. 

 Pages 420, 421. 



3. Insects do not cause the disease. Page 423. 



4. Fungi, especially the powdery mildew, may aggravate the 

 condition to a limited extent, but they cannot be held as the prime 

 cause of the trouble. Page 423. 



5. The " blight " or unnatural dying of the foliage is not the 

 cause of the malady, but is probably a manifestation of the action 

 of the same causes which produce the shelling of the grapes. 

 Page 424. 



6. The stems shrivelling before the berries mature is another 

 condition produced by the same cause. Page 425. 



7. The premature ripening of the berries is due to the same 

 causes as the blight of the leaves and the abnormal condition of 

 the fruit stems. Page 425. 



8. The premature ripening of the wood, while it may to a 

 certain extent be the cause of the shelling, can scarcely be con- 

 sidered as the fundamental cause of all the trouble. Page 425. 



9. Vines which are allowed to overbear are probably more lia- 

 ble to shell than are those not in the same condition. The weak- 

 ening of a plant causes it to succumb more easily to unfavorable 

 conditions. Page 425. 



10. Too much wood may increase the extent of the trouble, 

 for when the wood ripens it apparently takes its required nourish- 

 ment at the expense of the fruit. Page 426. 



11. Too rich land will scarcely cause shelling provided the 



* Note. — The conclusions regarding the shelling of grapes have been 

 drawn almost entirely from one season's observations, and the subject should 

 receive further attention in the future. 



