30 



THE HOP APHIS IX THE PACIFIC REGION. 



QUASSIA EFFECTIVE ONLY BY CONTACT. 



There is an erroneous impression among some growers that the 

 quassia spray after it has dried upon the leaves will kill the aphides 

 which later appear upon them. The quassia, as well as the other 

 sprays used for the hop aphis, is effective only when in actual contact 

 with the insects. 



EFFECT OF SPEAY MATERIALS UPON THE QUALITY OF SPRAYED HOPS. 



It was suggested by some growers that nicotine sulphate, whale- 

 oil soap, and quassia extract might injuie the quality of the hops on 

 which they were applied. In order to test this point some nearly 

 ripe hops were sprayed with the following materials, and when the 

 crop was being picked these sprayed hops were picked, dried in the 

 kiln with the other hops, and later sent to Washington for analysis: 



line sulphate. 1-1.000; whale-oil soap. 4 pounds to 100 gallons. 

 X: -tine sulphate. 1-2.000; whale-oil soap. S pounds to 150 gallons. 

 Nicotine sulphate. 1-3.000: whale-oil soap. 4 pounds to 100 gallons. 

 Blackleaf tobacco extract. 1-60 and 1-75. each with 2 pounds of whale-oil soap to 



.-allons. 

 Quassia chips. 7i pounds; whale-oil soap. 9 pounds to 250 gallons. 



The following analyses were received from the Bureau of Chemistry: 

 Table VIII. — A of hops sprayed with various insecticides. 



Xo. 



Wha^oil 1 



1 



3 



- 







None. 

 None. 

 None. 



None. 

 None. 

 None. 



None. 

 None. 

 N :>ne. 

 None. 

 None. 

 None. 



The quassia was not tested for. as there is no test that is applicable. 



From the above analyses it is evident that the nicotine or whale-oil 

 soap that remained upon the hop cones was not present in sufficient 

 quantities to be detected by a chemical analysis, and therefore would 

 not injure the quality of the hops. 



The flour paste is composed of starch and gluten, which has no 

 distinct flavor or odor, and even through it were present in large 

 amounts it can not be conceived how this material could influence 

 the quality of the he a 



DIRECTION IN WHICH TO WORK. 



Since the winged aphides travel largely with the wind, the best 

 results will be obtained, especially where the winds are prevailingly 

 from one direction, by working with the wind. If this is done the 



