CONTROL OF THE HOP APHIS. 



31 



winged aphides will not be able to migrate to the sprayed hops so 

 readily as if the wind were blowing from the unsprayed hopvines to 

 those which have been sprayed. 



CONTROL ON PRUNE. 



The hop aphis apparently is capable of migrating some distance, 

 provided the wind is right, and in prune-growing sections it is impos- 

 sible to kill all of the migratory insects. Where there are only a 

 few prune or plum trees in the neighborhood, however, the destruc- 

 tion of any nonproductive trees and any wild plums that may be 

 present will reduce the number of trees that will have to be sprayed. 



The spraying of the plums and prunes can not be relied upon for 

 the control of the hop aphis, but where it is thoroughly and systemat- 

 ically done the severity of the season's infestation may be greatly 

 lessened. Work along this line is strongly recommended. 



FIELD OBSERVATIONS. 



About the time that the aphides are expected to appear upon the 

 plum or hop it is advisable to go through the prune orchards or hop- 

 yards and note the conditions. Careful observations, if maintained 

 throughout the season, will keep the grower informed as to the 

 severity of the infestation in all parts of his hopyards. He will then 

 be able to check the infestation before any serious damage has been 

 done. 



SPRAYING REPORT. 



The following form of a daily report was successfully used by Mr. 

 H. N. Ord at Independence, Oreg., in 1912, to keep a record of the 

 spraying operations in the field: 



Date. 



No. acres 

 infested. 



No. acres 

 sprayed. 



No. gallons 

 used. 



Formula 

 and cost 

 per 100 

 gallons. 



Effective- 

 ness of 



spray ap- 

 plied three 

 days before. 



No. 



machines 



used. 



No. acres 



sprayed per 



machine. 



Cost of 



operations 



per acre. 

































































































































If such a report is faithfully kept the grower will always know the 

 condition of his hopyard and what his spraying operations are costing 

 him. 



SPRAYING MACHINERY. 



Several forms of outfits may be successfully employed in the hop- 

 yards provided that they meet the following requirements: The 

 machine should have a tank capacity of from 75 to 200 gallons, 



