AKD WINE MAEIXTQ. 118 



TREATMENT FOR MILDEW AND ROT. 

 An address to the Missouri State Horticultural Society. 



BY HERMANN JAEOEB. 



Black rot and Pero^iospora, or downy mildew, have 

 been the two most formidable foes of American grape- 

 vines. The ravages of these microscopic mushrooms 

 discouraged and dislieartened nearly all cur grape grow- 

 ers. The few men that kept their vineyards, came to 

 the conclusion that profit from grape growing could not 

 be expected, except, perhaps, with very few varieties resist- 

 ing rot and mildew better than most others. 



Nothing, therefore, could have pleased us better than 

 the fact established after three years' experimenting with 

 copper remedies, under the direction of our National 

 Department of Agriculture ; — the fact, I say, that not 

 only mildew (as had already been proved in France), but 

 likewise the still more fatal pest of black rot, are under 

 our control, and can both be entirely prevented by cor- 

 rect spraying with Bordeaux mixture or other copper 

 solutions. This was in 1890. Our experience in 1891 

 fully verified this claim. The season of 1892, with an 

 extremely wet spring and early summer, proved that by 

 spraying we can succeed in most unfavorable years, not 

 only with Norton, Ives and Perkins, but with Rogers' 

 Hybrids, Delaware, Triumph, and the long list of varie- 

 ties that, even in fair seasons, used to be a mere source 

 of disappointment. 



Last summer it required from five to eight sprayings 

 to keep our vines free from rot and mildew, while three 

 to five applications are quite sufiicient in ordinary sea- 

 sons. A neighbor of ours who postponed his spraying, 

 because the incessant rains would be sure to wash oflf the 

 solution, made almost as complete a failure as another 

 neighbor who argued si)raying was useless until dry 

 weather had set in, because 'Hho rain would wash awaj 

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