440 



MANUAL OF FRUIT DISEASES 



the leaf or the fruit and produces infection during the rain, not 

 before nor after. Get the fungicide on ahead of the rain and 



thus ahead of the 

 fungus. Watch 

 the weather maps 

 and the develop- 

 ing blossoms. It 

 will be more prof- 

 itable in some 

 cases to spray a 

 little before the 

 host is in just the 

 right condition in 

 order to get in 

 ahead of a rain- 

 period. Long, 

 rainy, cloudy 

 periods are the 

 dangerous ones. 

 Heavy showers 

 followed by rapid clearing seldom afford conditions favorable 

 to serious infection by orchard fungi. 



The period for effective applications of fungicides, in practi- 

 cally all cases, is a brief one ; at most a few days, more often 

 only a day or two. This means that equipment, labor and 

 materials necessary to cover the trees in a short time must 

 be provided. The continuous running of one sprayer in a large 

 orchard throughout the season is largely a loss of time and 

 money. Fungicides to be effective must be applied at just 

 the right time. 



Thoroughness is second only to timeliness as a factor in 

 determining the success of spraying or dusting operations. 

 Since fungicides are applied to protect, every part of the sus- 

 ceptible surface must be covered. In spraying this cannot be 



FIG. 125. Apple-blossoms in proper stage for the 

 first application of a fungicide. 



