BETTER FRUIT 



Pioneer Horticultural Journal of the Pacific Northwest 



Entered as second-class matter April 22, 1918, at the Postoffice at Portland, Oregon, under act 



of Congress of March 3, 1879 



Volume XVI 



Portland, Oregon, February, 1922 



Number 8 



What of the Use of Spreaders ? 



By A. L. LovETT 



Entomologist, Oregon Agricultural College Experiment 



SOME of the more scientific phases 

 of spraying have seemed, at best, a 

 bit bewildering and there are few if 

 any phases of the horticultural game in 

 which changes have been more rapid or the 

 kaleidoscope of improved practices has 

 presented a more constantly varying aspect 

 from year to year. As a grower has 

 remarked and, no doubt, many others have 

 thought, "just as we master the details of 

 one new spray practice and begin to accept 

 it as gospel, here comes another new 

 wrinkle and the whole matter has to be 

 threshed over again." 



This avalanche of improved practices in 

 spraying; improved combination sprays, im- 

 proved technique in application, higher 

 powered outfits, the spray guns, etc., is the 

 most concrete and positive evidence of the 

 importance of the subject and of the 

 demand for more effectual and less ex- 

 pensive practices in spraying operations. To 

 glance through a catalogue of sprayer equip- 

 ment of twelve years ago or to peruse a 

 spray bulletin of that period will impress 

 one of the inadequacy of machinery and 

 methods then pertaining. 



How utterly futile it would be to attempt 

 with such machinery the commercial 

 orcharding of today with the pests it is now 

 necessary to combat and the standard of 

 excellence now demanded. Spraying is a 

 costly operation; it is an exacting practice 

 and all other things being equal, the grower 

 who most nearly approaches the ideal in 

 improved spray practices will achieve the 

 highest degree of control at a minimum 

 output of time and expense. 



Necessarily, with new spray practices 

 developing so rapidly, some must be still in 

 the experimental stage; or where of proven 

 merit for one section must needs require 

 some modification to adjust them to max- 

 imum efficiency in another section. 



The development of spreaders to be 

 added to the poison spray solution for its 

 phyiscal improvement is one of the more 

 recent improved practices. Yet, in spite of 

 several years of fairly careful experimental 

 evidence favorable to spreaders as a com- 

 mercial orchard proposition, they are still 



yiiitriiiiiiiiiiitiiiiiniiiiiiiiiiiiiiiiMitiiiiiiiriiitiiiiiiiiiii iiiiiiiiiiiiiiiiimiiiiiiiiiitiiriiir: 



I Orchard exferts of the Pacific | 



I Northwest undoubtedly deserve credit | 



I for fioneering in the use of sfray | 



I sfreaders, and the ivriter of this | 



I article has been in the forefront in | 



I these i?!vestigations. It may be a ^ 



I long time, as Professor Lovett here \ 



i indicates, before the last tvord on | 



I sfreaders has been written. In the | 



I meantime painstaking investigations | 



I are each year leading the horticul- | 



I turists nearer the basic fundamentals | 



I as to values and best types of | 



i spreaders. The facts relating to the \ 



I Oregon tests and points wherein | 



I results differ in different sections | 



I are here set forth. | 



fiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiriiitiimiiiiiiiiiiiiiiiiiiiiiiiiiitiiiiiiiMiiiiiii^ 



"on trial." Believing it a desirable thing 

 to crystallize our present knowledge, prac- 

 tices, reactions and trend regarding 

 spreaders, we have attempted in this article 

 to summarize as far as possible this infor- 

 mation. 



Historical — The addition of materials 

 to the poison spray solution to improve its 

 physical properties is by no means new. 

 Various materials including glue, molasses, 

 soap, soap bark, gelatine, etc., have been 

 used from time to time in more or less 

 isolated cases for specific pests where the 

 investigators appreciated the necessity for 

 improving the "spread" of the poison solu- 

 tion. 



Probably the first large scale investiga- 

 tion of spreaders for poison sprays, with a 

 rather general application to the economic 

 control of orchard pests, were those under- 

 taken at the Oregon Experiment Station. 

 The problem is still under investigation 

 and surely the last word on spreaders has 

 not yet been written. It is not worth while 

 to review the Investigation in detail. Among 

 the really promising and practical substances 

 tested as spreaders were: Calcium casenate, 

 glue, gelatine, saponin, and oil emulsions. 

 In considering their qualities as a^ spreader 

 the following factors were necessarily taken 



Station 



into account: AvallabUlty, (was the source 

 of supply adequate); compatabillty, (they 

 must not react unfavorably with any ord- 

 inary spray material or combination of 

 spray materials); efficacy, (in reasonable 

 amounts they must actually give satisfactory 

 results) ; ease of preparation (complicated 

 formula:, cooking, any operation requiring 

 much close or additional work meets with 

 little favor among our growers) ; the cost 

 must be reasonable. 



With these factors as the standards of 

 excellence the casein spreader appeared the 

 most promising. Oil emulsions are not such 

 a poor second except that they are less fool- 

 proof. If we could be sure our growers 

 would handle an oil emulsion properly in 

 all cases, it could become a close competitor, 

 but the element of danger is too serious a 

 risk for the general recommendation of oil. 



CASEIN SPREADER— In the tests at 

 the Experiment Station in the earlier 

 field work ordinary commercial ground 

 casein was employed. During the earlier 

 commercial trials while growers "mixed 

 their own," not all reports were favorable. 

 The process in itself was subject to failure 

 where any short cuts were attempted, then 

 the casein available was varLible in size of 

 particles and in character. 



Fisher of Washington, investigating the 

 control of apple mildew, was also working 

 with spreaders and recommended some 

 modified formula; .and methods in prepar- 

 ation that were adopted in some cases. All 

 told, the 1920 season may be summarized 

 as one where the general idea of the use of 

 spreaders gained ground rapidly, the use of 

 spreaders but little. 



With the opening of the season of 1921 

 some commercial companies had become 

 interested and commercial casein spreaders 

 appeared on the market. Of the powdered 

 forms, which were by far in the majority, 

 it may be said that In general they repre- 

 sented a high grade casein, ground some- 

 what finer than the ordinary commercial 

 product and thoroughly mixed In definite 

 proportions with hydrated lime. These 



