52 



BUSHBERG CATALOGUE. 



DISEASES OF THE GRAPE-VINE. 



INTRODUCTORY REMARKS. 



The vine, despite its vigor and longevity, is 

 subject to diseases the same as other organisms. 

 As the causes of these diseases can not be wholly 

 eliminated, and as comparatively few of the mala- 

 dies can be prevented or cured, our first aim 

 should be toward selecting healthy plants and 

 hardy varieties. 



You have already been warned against planting 

 grape-vines in heavy, wet soil, where water stag- 

 nates, or in places exposed to early and late frosts. 

 You have been impressed with the necessity of 

 clean cultivation, stirring the soil,* proper train- 

 ing, and thinning the fruit. If these points be 

 disregarded even the healthiest and most vigor- 

 ous varieties of vines will become diseased. 



Thaulvs to the efforts of scientists in both this 

 countrj' and Europe, our knowledge of grape dis- 

 eases, especially those caused by parasitic fungi, 

 has been materially increased during the past few 

 years. Our National Government has taken an 

 Important part in this work, and hand in hand 

 with our sister Republic France, has done a great 

 deal towards clearing up the mystery surround- 

 ing the subject. To the French we owe the dis- 

 covery of the Bordeaux mixture, the remarkable 

 effects of which, as a fungicide and as an agent 

 capable of producing physiological effects on the 

 higher plants, ai-e as yet only partially under- 

 stood. 



At the time the last edition of this catalogue 

 was issued our knowledge on the subject of grape 

 diseases was very meager. However, through 

 the kindness of our lamented friend, Dr. Geo. 

 Engelmann, we were able to present to our read- 

 ers, the latest known facts on the subject. As a 

 tribute to the memory of Dr. Engelmann we have 

 decided to publish again the article penned by 

 him, and first in the Transactions of the Academy 

 of Science, St. Louis. 1861, Vol. II, p. 165, and re- 

 vised by him for this catalogue in 1883. Many of 

 the points mentioned in the paper have long been 

 settled, still there is no gainsaying the fact that 

 the majority of the statements are as valuable to- 

 day as they were when written. 



We give below Dr. Engelmann's article, fol- 

 lowed by another prepared at our request bj^ Mr. 

 B. T. Galloway, of the United States Department 

 of Agriculture, who is acknowledged autliority on 

 this subject. Mr. Galloway's article, briefly and 

 in a practical manner, brings together the latest 

 facts on grape diseases and their treatment. 



The Diseases of Grape- Vines. 



BY DR. (JEORGE ENGELMANN. 



"The diseases of the grape are caused 

 principally by animal and vegetable parasites. 

 I leave others, who are more conversant with 

 the subject, to treat of the former, and will 

 niereh' state here that our sjiecies have all 

 grown up with the Phylloxera, and would 



* We are aware of the fact that in certain season.? and 

 peculiar soils, neglected vineyards, fillert with jjrass and 

 weeds, have osc;i))fd discuses and borne full crops, wliile 

 well-hoed and cultivated vineyards suffered sevei'ely, 

 especially from rot. Such cases, however, are excep- 

 tions, not the rule; notwithstanding, they have led 

 some srape-srrowers to advocate non-cultivation and 

 "ven srass-sowins in their vineyards. As a result of 

 Ills in a few years the vines became stunted and un- 

 productive. 



long ago have been extinguished , or rather 

 never could have lived, if that insect had 

 such power over them ; but they as well as 

 the insect live on, the latter having no other 

 nourishment than the grape-vines and their 

 I'oots — 3'ou may call it an accommodation be- 

 tween them. 



"More important for us in America are the 

 fungous diseases, which do our grape crops 

 more harm than the Phylloxera. It is said 

 that in Europe the}' have discovered over two 

 hundred kinds of fungi which live on the dif- 

 ferent parts of vines, but fortunately only a 

 few of them are really injurious. These are, 

 above all, the mildew of the leaves and the 

 black rot of the berries. In Europe, besides 

 our mildew, which has latel}' been introduced, 

 the}^ have the Oidium and the Anthracnose. 



"The Mildew {Peronnpora vUicoki) appears 

 in frostlike, white spots on the under side of 

 leaves (hairy as well as glabrous ones), and 

 may generall}' be observed here in Missouri 

 from the beginning of June, fostered by the 

 sultry and damp or wet weather usual at that 

 season ; in the Eastern States it seems to 

 come on later in summer and in the fall. 

 Though most common on the leaves, it some- 

 times also infests the petioles of the leaves, 

 the stems of the bunches, and the very young 

 berries. But even if it does not attack the 

 latter, the effect on the leaves alone, which 

 turn brown in spots and are eventually par- 

 tially or completely killed, destro^'S the fruit, 

 the berries shriveling from the base, turning 

 light brown without falling off. This is here 

 sometimes termed " brown rot." 



"The fungus at first pervades the cellular 

 tissue of the leaf ; then, a few days later, the 

 minute fungous stems protrude through the 

 stomats (breathing pores) of the lower sur- 

 face, forming little upright branching plant- 

 lets, which might be compared to a miniature 

 spruce tree, singly, not visible to the naked 

 eye ; at the end of the branchlets they bear 

 the summer spores (conidia), which mature, 

 are discharged, spread by wind or otherwise, 

 and when moistened germinate with aston- 

 ishing rapidity. Late in the season the fun- 

 gus produces what are called the resting 

 spores (oospores) in the interior of the leaf 

 tissues, ancl while the others propagate the 

 parasite in summer, these larger and more 

 enduring ones keep alive through winter and 

 insure its growth in the following summer. 

 Thus it is seen that the dead, mildewed leaves, 

 containing the resting spores, really do pre- 

 serve the germs for the next season's mildew. 

 These leaves ought to be destroyed by care- 

 fully gathering and burning them, or by 

 burying them deep in the ground. The 

 direct destruction of the funorus has often 



