Proceedincs. 11)23 191 



eontnil. DeOn^-, repnrtinji- (jn an arscnatf fulia^r spray for recl-liuiupcd 

 caterpillars, reports supci'ior ('oiitrol where casein spreader was 

 employed. 



In the Wenatehee section of Washington there is a general impres- 

 sion that spreaders improve the efficiency of the spray. In the Yakima 

 section less spreaders have been used, and there is a general sentiment 

 to the effect that spreaders do not improve the killing efficiency. 



Ill 1hi' Twin P'alls section of Idaho, spreaders were (juite genei-ally 

 e)niilo.\'e(l. and tlieir use has received a most hearty enilorsement from 

 the growers. It would seein that they are enthusiastically united in 

 the opinion that spreaders materiall.v increased the killing efficiency. 

 Where sprea<lers lunc been used in Oregon there is a general feeling 

 thai the control has been improved. However, recent investigational 

 plats do not bear this out in any striking detail. 



iSummarized. we ma.v sa.v that while there is much evidence to indi- 

 cate that the addition of a s]u-eadi'r to the i)oison spray solution increases 

 its killing efficienc.\-. it is decidedly d<iubtful as to just what extent this 

 is true. It is our opinion that the value of a spreader in this regard 

 will be. to a considerable extent, in proportion to the efficacy of the 

 spray outfit; the excellence of the spray technique and the judgment in 

 ]iroper timing of the spray operation. Where any or all of these are 

 faulty, the value of the spreader increases proportionately. 



2. Does fhc Spreader Improve the Spread of the Spray f 



All reports are agreed that with the addition of a spreader one 

 iibtains a smoother, less conspicuous and a more even distribution of 

 the spra.v. This accomplishes two outstanding results of merit. The 

 even, inconspicuous covering renders the fruit less likely to unfavorable 

 suspicion regarding poison spray covering and makes wiping unnecessary 

 in many instances. By avoiding the heavy blotchy covering of the fruit 

 with the late summer spray, the red varieties of apple color up more 

 evenly, improving the appearance and grade of the mature fruit materi- 

 ally. 



This factor of a sniootli. inconspicuous covering, thus avoiding the 

 blotchy spray deposit and resultant uneven coloring, is really important, 

 and to many growers serves as a good and sufficient reason for the enthu- 

 siastic adoption of spreaders in tlieir late summer applications. 



3. Does till iiiliJition of a Spreader Inerease the Covering Power of the 

 Sprat) Solution so More Trees inatj be Covereel per Tank of Sprayl' 



Some growers have checked on this point fairl.v carefully and are 

 convinced that there is a material increase in the number of trees one 

 may cover with a tank of spray where a spreader is added. Many have 

 not checked on this, and a note of warning on the point is wortliy of 

 thoughtful consideration. It would be a most unfortunate situation if 

 the grower, imbued with this idea of a quicker covering with less 

 mati'i'ial. arlually failed to nsc sufficient time or solution on tile tree to 



