715 



ExperimenU near NewarJc. — These were on Concord grapes in the 

 vineyard of the Randolph Peters' Nursery Company, where the conditions 

 were particularly favorable to the rot and other diseases. The plan of 

 the experiment is sliown in a diagram. In addition to the fungicides 

 used in Dr. Black's vineyard, a moditied eau celeste and mixture ISTo. 

 5, U. S. Department of Agriculture, were applied to certain vines. 

 Six applications were made between May 10 and August 7. 



In order, as before, to avoid the necessity of washing the fruit sprayed with the 

 Bordeanx mixture, the last two sprayings of these vines (on July 21 and August 7) 

 were made with the nioditied eau celeste. Owing also to the previous scorching of 

 the foliage by the sulphate of soda in the precipitated carbonate of copper, it was 

 decided to discontinue the original form of this mixture, and accordingly at the last 

 two sprayings the second form of the mixture was used, by adding to each 25 gallons 

 of water I pound of the dry carbonate of copper, and a solution containing 3 ounces 

 of common glue. The addition of a small amount of glue to the mixture caused a 

 remarkable adherence of the fluid to the berries, which was not the case when the 

 glue was omitted. 



A table shows the result for each kind of treatment. The percent- 

 ages of diseased fruit varied from 46.5 for one row of the unsprayed vines 

 to 2.3 where the i)reeii)itated carbonate of copper was used, with the 

 winter treatment. The yields per vine were <piite irregular, probably 

 due to the neglected state of the vineyard. The results of this experi- 

 ment may be summed up as follows : The ammoniacal carbonate of cop- 

 l)er and the carbonate of copper and carbonate of ammonia mixture did 

 not give satisfactory results. "The precipitated carbonate of copper, 

 Bordeaux mixture, modified eau celeste, and mixture No. 5, U. S. 

 Department of Agriculture, were all effective fungicides in protecting 

 the vines from rot. From the point of protection from rot the precipi- 

 tated carbonate of copper takes the lead, but, all things considered, the 

 Bordeaux mixture seems to have done better work by apparently stimu- 

 lating the growth of the vines. Unsprayed rows left between a 

 majority of others which are sprayed fail to become a measure of the 

 loss in an untreated vineyard." 



With a view to studying the progress of the disease during the sea- 

 son of 1890, bags were put upon twenty-five clusters of grapes each 

 week, from May 22 to August 4. On September 2 all the bags were 

 opened and the diseased and healthy berries in each lot counted. The 

 results, as indicated in a table and diagram, indicate a period of great 

 infection between June 5 and 14, and a second infection between July 

 3 and 11. In the first case the weather was favorable to the progress 

 of the disease, but in the second case the attack can not be explained 

 by the meteorological conditions. 



Directions for preparing and applying the fungicides used in these 

 experiments, wholesale prices of materials, etc. — The methods used in 

 preparing the six different fungicides used in the experiments reported 

 in this bulletin, are described. 



The cost of the materials in 100 gallons of each of the fungicides is 



