NEW YORK EXPERIMENT STATION BULLETINS. 



373 



Dates of 

 applica- 

 tions. 



Aug. 20 



Plants used. 



Apple (Gravensteiri) 



Pear (Sheldon) 



Quince (Mammoth). 



Peach (Mt. Rose) 



Grape (Gaertner)... 

 Egg-plant 



Dates of observation and 

 per cent of injury. 



Aug. 22. 





 5 

 

 10 

 

 



Sept. 5. 



10 

 5 

 



90 

 

 



Although but one application was made, the first table shows serious 

 injury to the peach, and the apple was also affected, but only slightly. 

 The second table shows injury to the peach, apple, and pear, the addition 

 of Paris green again making the solution more caustic. 



Conclusions. — The chloride of copper must be used in small quantities. 



Its caustic action upon foliage is increased by the addition of Paris green. 



FUNGICIDAL VALUES OF THE NEW COMPOUNDS. 



The hydrate, the borate, and the chloride of copper were applied to 

 pumpkin and squash vines, which are usually attacked by mildew (Oidium 

 erysiphoides var. Cucurbitarum), in order to determine their real value as 

 fungicides more accurately than could be done upon the quinces. The 

 Bordeaux mixture was used for comparison. Two applications were made, 

 the first Sept. 8, the second Sept. 18. The solutions were made according 

 to the following formula: 



Bordeaux mixture, as on page 370. 



Hydrate of copper. No. 1, \ pound in 22 gallons of water. 



No. 2, £ pound in 22 gallons of water. 



Borate of copper. No. 1, \ pound in 22 gallons of water. 



No. 2, \ pound in 22 gallons of water. 



Chloride of copper. No. 1, 1^ ounces in 22 gallons of water. 



No. 2, 3 ounces in 22 gallons of water. 



None of these solutions appeared to injure the foliage. The following 

 table shows what per cent, of the foliage was attacked by mildew Septem- 

 ber 26, when the notes were taken. 



As different varieties of cucumber were sprayed, each plot had its 

 own check which contained some vines of the same variety as those 

 treated. 



The numbers showing the per cent, of injury to the foliage treated with 

 the copper hydrate are not strictly accurate, for the ground was so thickly 

 covered with vines that it was difficult to apply the fungicide to all 



