April, '21] DUSTING DISCUSSION' 231 



President Newell assumes the chair. 



President W. A. Orton: Three points in particular I want to men- 

 tion ^vith respect to dusting for the control of both insects and plant 

 diseases: First, that our outlook be from this time forward, and not 

 backward, — toward the possibility of success in the future regardless of 

 failures in the past; second, let us organize our work to bring to bear 

 upon these problems the best help of all kinds of specialists concerned — • 

 entomologists, pathologists, chemists, engineers, and farmers; third, 

 that our experimental methods should be adapted to the complexity of 

 the problem. 



With respect to this morning's discussion, it seems to me that it is not 

 worth while for any of us to speak in the discussion upon our past 

 failures unless we know the reason why. We have had lots of them. In the 

 field of truck crop diseases the failures far outnimiber the successes, 

 but we do feel that the whole question of dusting ought to be reopened, 

 because the fruit and truck growing industries demand that simpler 

 and easier methods of disease control should be introduced. 



I feel personally, particularly in our own field, the very great impor- 

 tance of concentrating the services of specialists in many different lines. 

 We cannot as pathologists feel that we are planning our work properly 

 unless we are. advised as to the life history of the insects which have to 

 be dealt with. We need the help of the chemist to determine the com- 

 position of our mixtures ; we need the help of the plant physiologist to 

 determine the reaction of the chemicals upon the plants; we need the 

 help of the chemist to determine by actual analysis what amount of 

 fungicides may be present upon the leaves, what amount is washed off 

 by the rains, the relative adhesiveness of the compounds. We need the 

 help of the engineer to plan better machinery for applying our fungicides 

 and insecticides. 



Our experimental methods, I feel, have not been planned correctly. 

 One speaker has mentioned that results differ greatly if a short time 

 intervenes between the applications that are being compared. One 

 spray on one day and another three days later give different results. 

 That is true, but are we not making a mistake in planning our experi- 

 ments in the office in the beginning of the season and carrying them 

 through on a fixed schedule regardless of developments during the season. 

 When we plan to spray every two weeks, such and such a mixture, 

 such and such quantities, are we not like the general in the war who says 

 "I will fire my guns in the general direction of the enemy at ten o'clock 

 on Mondays, Wednesdays and Fridays?" The chances are if he does 

 so the enemy is still snugly protected in bomb-proof dug-outs, or has 

 not yet come out in the field, or is forward in the skirmish line. Now we 



