160 MISSOURI STATE HORTICULTURAL SOCIETY. 



ing periods which would prove fatal to the less protected stylospores; at 

 least, all the evidence at hand would lead us to believe that such is the 

 case. For a long time the summer stage of the fungus was known as 

 PJioma uvicola, but after the discovery of the form last described this 

 name was dropped, and the name for the mature form, which is PJiysa- 

 lospora Bidzucllii, was adopted, 



TREATMENT. 



From what has been said, it will be understood that the treatment 

 of this malady must be preventive. The germs of the disease are omni- 

 present and are ready to attack the leaves and fruit whenever the condi- 

 tions are favorable. During a period of drought there is usually less rot 

 simply because moisture is necessary for the germination of the spores. 

 The latter are present, however, no matter how dry the season may be, 

 and at the very first approach of moisture they germinate and, as a re- 

 sult, the whole grape crop, which gave every promise of maturing in per- 

 fect condition, soon becomes a worthless, shriveled mass. 



Experience has taught us that little benefit is to be derived from a 

 destructive treatment, such as burning the diseased branches, plowing 

 under the rotten berries, or collecting and burning the latter, no matter 

 how thoroughly such a course is followed, there are always germs enough 

 left to insure the propagation of the fungus. So far, the only methods 

 which have proved successful or given promise of success in combatting 

 the enemy, are the following : 



1st. Selection of varieties not subject to the rot. 



2d. Bagging. 



3d. The application to the vine of such substances as will destroy 

 the germs or prevent them from gaining access to the tissues of the leaves 

 or fruit. 



Of the first and second methods little need be said. Every grape- 

 grower knows that certain varieties are less subject than others to the 

 attacks of the parasite, and a judicious selection of resistant vines will to 

 a certain extent result in a mitigation of the evil. Our object in bagging 

 the fruit is to exclude the germs. From what has been said of the life 

 history of the fungus, it will be readily understood that the bags must be 

 applied early, in fact, the greatest success resulting from the use of bags 

 has been obtained when they were applied soon after the flowers were 

 well open. 



