54 



Caesar (L.). Dusting for Tender Fruits and Apples.— 4M Ann. Rept. 

 Fruit Growers' Assoc. Ontario, 1916; Toronto, 1917, pp. 47-51. 

 [Keceived 3rd December 1917,] 



Experiments witli dusting were carried out in an apple orchard of 

 162 large trees, 92 being selected for dusting, 51 for spraying with 

 liquid hme-sulphur and lead arsenate, and the remainder for spraying 

 with soluble sulphur and calcium arsenate. The whole orchard was 

 first heavily sprayed with lime-sulphur to control San Jose scale 

 [Aspidiotus perniciosus], which was somewhat abundant, and the 

 selected trees were then dusted twice with a mixture of 85 per cent, finely 

 ground sulphur and 15 per cent, arsenate of lead, the first application 

 being given just as the blossoms were ready to burst, and the second 

 very soon after they had fallen ; 3 lb. of the mixture was sufficient for 

 each tree. The trees receiving liquid sprays were treated with equal 

 care and at the same times, to ensure a fair comparison. The results 

 showed that the foUage on the dusted area was decidedly superior to 

 that which had been sprayed, while there was very little difference 

 in the degree of control of the codhng moth [Cydia pomonella] and the 

 lesser apple worm \Ena.rmonia prunivora], the lime-sulphur and lead 

 arsenate perhaps giving the better result, as it also did in the case of 

 arp-ple scab. 



Plums dusted against brown rot showed a decided benefit as 

 compared with untreated trees. 



The most important point in the treatment of sweet cherries was 

 that those treated with a liquid spray still showed evident traces of 

 it at picking time, while those dusted, even only two or three days 

 before picking, showed none. In a dust spray apphed so late, the 

 poison would naturally have to be omitted and only the sulphur used. 



Peaches were found to hold the dust for several weeks after appli- 

 cation, hence in bad years the method should afford ample protection. 

 Although the year was not a good one for testing purposes, it was 

 evident that dusting was of considerable value in the control of 

 powdery mildew on grapes. 



The comparative cost of dust spraying varies with the size of the 

 tree, being slightly cheaper than liquid sjDraying for large trees, 50 j)er 

 cent, dearer for medium trees, and more expensive still for small trees. 

 In all cases the time required for dusting was much less than that 

 occupied in liquid spraying, varying from -| for large trees to ^ for 

 small ones. On the other hand the liquid spray held on the leaves 

 much better than the dust, and though in the long run the dust method 

 will probably prove satisfactory, caution must be exercised in the 

 purchase of dusting machines at the present time. 



Caesar (L.). Insects attacking Fruit Trees. — Ontario Dept. Agric, 

 Toronto, Bull. 250, July 1917, 49 pp. 58 figs. [Received 3rd 

 December 1917.] 



This popular and comprehensive bulletin deals with all the well- 

 known insects attacking fruit trees in Ontario, giving the methods of 

 control for each and directions for spraying by both wet and dry 

 methods. A spray calendar and index are appended. 



