22 THE REPORT OF THE Xo. 36 



the third application, the one just after the blossoms have fallen, I shall recom- 

 mend lime-sulphur 1 gallon to 40 gallons of water, and the usual amount of 

 arsenate of lead. 



At present I do not feel like advising against the substitution of arsenate of 

 lime for arsenate of lead with lime-sulphur, though I am not yet convinced that 

 it is so safe. A warning, however, should be given, that some brands of arsenate 

 of lime are much inferior to others and much less safe. 



In a very wet period I should prefer Bordeaux to lime-sulphur for the spray 

 just before bloom, because it will remain on the trees longer and thus keep 

 off scab longer than lime-sulphur. I do not recommend it for the third application 

 because it russets the fruit, some years very badly and every year to some extent. 



As to the dropping of fruit which follows later applications of lime-sulphur 

 in Nova Scotia, this has not taken place in Ontario in my own or any other 

 person's experiments that I am aware of. I believe the difference in climate 

 between the two Provinces accounts for the different results obtained. 



As to the dust method of treating orchards, I do not intend to recommend 

 it for the present. I have obtained good results from it myself but the fruit 

 growers 'do not succeed well with it. They also object to the cost. The new 

 spray guns have made them much better satisfied with liquid sprays. 



Pkof. Paerott: In our State I believe we have more pests to combat than 

 you have in your fruit growing sections. We have San Jose Scale, and use lime- 

 sulphur because it is cheap and nearly fool-proof from the standpoint of the 

 farmer. We have the Pear Psylla, which is a very common pest in our pear 

 growing sections, and we rely on lime-sulphur to combat that insect ; and we have 

 the various mites which are held in check by sulphur sprays. Considered from 

 the standpoint of the dormant application we have to consider some spray mixture 

 which will handle those particular pests. 



Our change from Bordeaux to lime-sulphur was brought about by the attitude 

 of our fruit growers. There was a period in the "90''s and ten or fifteen years 

 ago when growers suffered severe injury from Bordeaux mixture. As a result 

 of this injury the farmers swung over to the use of the lime-sulphur, because 

 the fruit presented so much better an appearance from its use. As far as New York 

 is concerned (and I think I am safe in speaking for the men at Cornell as well 

 of those of the New York Experiment Station) we would not dare to recommend 

 Bordeaux to apple growers in our State ; it causes too much injury. 



I have been very much interested in the question of dropping of fruit. It 

 seems to me it is one of the points which should be looked into. For two years 

 we have carried on comparative experiments with lime-sulphur and arsenate of lead 

 and Bordeaux mixture and arsenate of lead, and in 1917 we had a larger drop 

 on the check trees than on those sprayed with lime-sulphur and arsenate of lead 

 or Bordeaux mixture and arsenate of lead. 



We tested nine brands of calcium arsenate this summer and also tested a 

 formula given by our Federal Government for home-made calcium arsenate. In 

 the work on the station grounds we had no injury, not even yellowing, in any 

 plot sprayed with a commercial brand, notwithstanding the fact that we gave all 

 four applications. We had, however, serious yellowing following the second applica- 

 tion of the home-made preparation. 



A point was made in regard to dusting. There is involved a consideration 

 of the fact that in certain districts of New York the red bugs are a most injurious 

 pest. We have no contact dusting material which favorably controls them. I 

 doubt whether dusting will get very much encouragement the coming season. 



