286 ANNUAL REPORT 



About the fifteenth of June there were some indications of dry- 

 rot, confined chiefly to Clinton and wild grapes. A small portion 

 of the berries shriveled, turned black, and after a time dropped 

 from the vine. Besides the black or dry rot, there are instances 

 of white rot, brown rot and bitter rot. What I suppose to be the 

 latter form became very serious in many localities last year. It 

 first began to appear about the last week in August. In some 

 clusters one-fifth of the berries were affected by this rot causing 

 the berries to color prematurely, but the pulp remained hard 

 and bitter showing that there had been a cessation of growth. 

 The berries thus affected usually fall to the ground by the time 

 the remainder of the bunch has perfectly ripened, but last year 

 did not do so, as is evidenced by the quality of the fruit placed 

 upon the market. I am informed that this rot and the mildew 

 were so bad in some vineyards that almost none of the fruit 

 matured to a good eating quality. I am strongly inclined to the 

 opinion that the hardiness of our vines depends very much upon 

 their immunity from mildew and that at least some types of the 

 fruit rot have their origin from the same cause. 



REMEDIES AND PREVENTURES. 



If, as some of the most intelligent vineyardists believe, the mil- 

 dew was the prime cause of the almost general low quality and 

 unripe condition of Minnesota grapes last season, it has become 

 a grave matter and threatens serious damage to an industry 

 for which we hoped much. In a recent conversation with one 

 of the leadihg growers of Houston county he made the state- 

 ment that the foliage was so badly affected by mildew at one 

 period in his vineyard that the fruit, at the time when it should 

 have been ripeuing, remained about stationary nearly a whole 

 month, and that he did not gather a pound of perfectly ripe fruits 

 Scores of smaller growers were caught in the same predicament. 

 Investigation has demonstrated to a certainty that the mildew 

 and rot are contagious diseases, or a fungus, that propagate 

 themselves and spread readily from plant to plant by means of 

 spores wherever conditions are favorable. 



The free use of sulphur apx^lied to the affected vines with a 

 sulphur bellows has long been in vogue for the destruction of 

 fungus. Some successful vineyardists have kept their vineyards 

 free from rot by picking off every affected grape as soon as it 

 shows it has been attacked by rot or insects, and then destroy- 



