19 



SULPHATE OF COPPER FOR THE PLUM WART. 



While the kerosene paste has proved satisfactory in tlie destruction 

 of the plum wart, it requires close personal examination of every 

 branch of every tree in order to destroy them all. This mode 

 of treatment is not expensive but is one that few growers will take to 

 kindly and some method requiring less close application has been 

 sought in the various solutions suggested for other fungi. 



Sulphate of Copper. To destroy all spores that might be attached 

 to the branches, some of the trees in the station and college orchard 

 were sprayed April 19th with sulphate of copper, 1 lb. to 22 gals, of 

 water. All parts of these trees were thoroughly wet with the solution. 



While it is difficult to determine positively, if the spores existing 

 on the branches of tl:e trees were destroyed by this a[)plication, from 

 the small number of warts developed on the trees sprayed, we think 

 that it was decidedly beneficial. 



To destro}' the plum curculio and the black wart atone operation, 

 a second application of the same solution was made May 17th, to 

 which Paris green was added at the rate of 1 lb. to 500 gals, of the 

 solution. 



This application so injured the foliage thai subsequent applications 

 of Sulpiiale pf copper and Paris green were made in the form of the 

 Bordeaux Mixture. This mixture was applied May 21st, May 29th, 

 June 7th and 17th and July 19th and 29th. No injury could be 

 discovered from the Paris green, even when the amount was as large 

 as 1 lb. to 200 gallons. 



Owing to the destruction of the fruit and the foliage by the first 

 application, positive results could not be determined as to the effect 

 of the Paris green upon the curculio, but in the case of trees that 

 were treated with the Bordeaux mixture and Paris green only, a very 

 large crop of fruit was matured while other trees not treated, lost 

 all their fruit from the attacks of the curculio. The number of 

 warts was t'er?/ decidedly less where treated with the copper mixtures, 

 than where untreated. 



One thing our experiments have demonstrated beyond a question 

 i. e., that plum trees, leaves and branches, may be kept covered with 

 mixtures of sidphate of copper., lime and Paris green for nearly the 

 entire season without noticeable injury and we believe that both the 

 plum wart and plum curculio may be held in check by this remedy. 

 Another season it is hoped that experiments may be made on a laro-e 

 soale in different localities throughout the state, to settle the question 



