124 INTERNATIONAL CONGRESS OF VITICULTURE 



was limited only by the quantity of material and the time available in which 

 to do the work. 



Some difficulty was experienced with the feeding mechanism of the 

 duster, and the experiment was finally performed by distributing nearly 50 

 per cent less sulphur per acre than had been planned originally for some of 

 the tests. A maximum of 40 pounds of either grade of sulphur was applied 

 per acre. Mildew was showing to a limited extent in all the vineyards. In 

 some cases it was necessary to search carefully to find spots and in others 

 small spots, particularly on the peduncles, were easily found. 



A half acre or more in each of 47 vineyards was dusted. These were 

 scattered over a territory about eight miles in length, and represented 

 several soil types. Nearly all the vines treated were Concord. It was 

 planned to make two applications, but subsequent happenings interrupted. 

 The first vineyard dusted was on July 20th and all were completed by July 

 31st. The average maximum temperature for the 22 days following the 

 treatment was 84, while the total precipitation for the same period was 

 but .83 of an inch. 



When the second application was begun it was seen that several of the 

 vineyards previously dusted were showing marked indications of injury on 

 the leaves. This in the form of burned areas over the blade or a drying 

 out of the margins. The second application was then abandoned. As the 

 time of maturity approached the injury showed more abundantly and in 

 some instances practically all of the leaves were functionless on one or more 

 canes of a vine. The fruit on such vines did not color and at harvest time 

 it was still red and unmarketable. In many instances the season's wood 

 growth did not ripen so that it was a problem to find fruiting wood for the 

 crop of 1915. In order to learn to what extent these conditions obtained for 

 all the vineyards, the growers were requested to report on the effect of the 

 sulphur to leaf, wood and fruit. Of the 30 from whom such information was 

 obtained 25 reported severe injury to leaf, fruit, and wood. "The leaves had 

 the appearance of having been burned and in extreme injury, the vines were 

 practically defoliated." "Wood growth and fruit development was conse- 

 quently checked." One vineyardist reported "that the most damaging effects 

 upon the foliage and wood appears to be on eight or ten rows adjoining, and 

 on either side of the dusted area." "In no other of my vineyards is such a 

 condition to be found." The extent of injury with these vineyards made 

 impossible the securing of reliable data as to the control of the mildew. 

 One grower of the thirty reported slight injury, but owing to the slight 

 amount of mildew present in the untreated sections, he was unable to detect 

 material results from the dusting. 



Four of the thirty reported no injury. Of this number three saw no 

 beneficial effects from the sulphuring. One of these, however, had sprayed 

 thoroughly with Bordeaux. One grower of the four reported almost complete 

 control. 



Just what factors entered to bring about these conditions is difficult to 

 say. Three of the four vineyards uninjured were dusted with fine sulphur, 

 yet a large number of those injured were treated with the same grade. Leaf 

 hopper injury to the foliage cannot be considered as a factor for very little 

 trouble was experienced the past year with this insect. Weather conditions 

 at and following the application seems to offer a possible explanation, at 



