The Black Rot of the Grape axd Its Control. 



401 



is too great to make the practice of value to the grower. It is not recom- 

 mended commercially. 



(e). The application of a spray mixture before the appearance of the 

 second set of leaves is of no value. The early applications do not destroy 

 the winter spores which are present, since these spores are enclosed in 



Fig. 103. — Ha)id-spraying grapes on Expcrimoital Plat, June 11, 1908. NoLe 

 the fog-like spray being produced. 120 pounds pressure; 1—20 inch hole in the nozzle; 

 50-60 gallons to the acre 



sacs which protect them from any spray which may be applied. The 

 first spray should be applied at the time of the appearance of the second 

 or third set of leaves. 



(f). The time of applying a spray in relation to the weather condi- 

 tions is an important consideration. The spores germinate immediately 



