34 N. S. ENTOMOLOGICAL SOCIETY 



At Annapolis the new 5-2 dust was compared with 4.4.40 

 Bordeaux, arsenate of lime, and no treatment. In both of 

 these fields the dust was thoroughly applied with a cyclone 

 hand duster. In the one case treatment continued throughout 

 the season with a very slight difference in favour of the dust 

 at the end. In the other case treatment did not begin until 

 about five per cent of the leaves were infected with late blight. 

 In the latter case the dust showed itself apparently superior to 

 the liquid in retarding the spread of the blight. 



At Hemmingford, P. Q., tests were made by Mr. C. E. 

 Petch with particular reference to the insecticidal value of the 

 dust. Three days after application the number of hills carry- 

 ing potato beetles was reduced from 2?7 to 8. It may be add- 

 ed that potato beetles were so numerous in this field that Paris 

 green to quote Mr. Petch "was almost useless." Our exper- 

 ience in Fredericton in comparing the dust and Paris green in 

 liquid Bordeaux, bore out this statement. It would appear 

 from our field and Laboratory tests that this dust does not de- 

 crease the killing value of arsenicals to the same extent as liquid 

 Bordeaux. 



At the Experimental Station, Charlottetown, P. E. I., a 

 number of tests were made, which appeared to place the 5-2 

 dust on a par with 4.4.40 Bordeaux in the control of potato 

 diseases and above the ordinary poisoned Bordeaux in the con- 

 trol of potato beetles. Unfortunately, unknown to us, the 

 field was very uneven having been used in previous years for 

 manurial and other experiments, so that no definite results of 

 value could be obtained. 



Results from Field Tests on the Apple. 





Unfortunately where the 2|-1 formula dust was applied 

 to the apple in a field way by Prof. W. H. Brittain, the orchard 

 proved so uneven that no reliance whatever could be placed 

 in the counts of insect and fungous injury. 



In tests at the orchard of Senator W. B. Ross, Middleton 

 as well as in Prof. Brittain's experimental orchard, no injury 

 followed the application of 2|-1, 5-2 and even stronger dust 

 formulas on the apple foliage. Some purple spot and some 

 russetting developed on the smooth skinned apples presumably 

 from the calyx or after blossom spray. 



