December, '11] METCALF: SPRAYING FOR GLOOMY SCALE 



517 



When our attention was first called to the destructive work of the 

 Gloomy Scale, it was our belief that home-made lime-sulphur (15- 

 15-50 or 15-15-30) or kerosene emulsion at 15, 20 or 25 per cent 

 oil would effectively control it, therefore during 1908 and 1909 various 

 experiments were tried as follows : 



Home-made Lime-sulphur (15-15-50) . Trees were sprayed in mid De- 

 cember and late February. Some benefits but not a satisfactory remedy. 



Home-made Lime-sulphur (15-15-30). Trees were sprayed in 

 mid December and the trees did better after the spraying, but it 

 was not a satisfactory remedy. 



Kerosene Emidsion (25 per cent oil) . Trees were sprayed in late 

 February. Not a satisfactory remedy, for practically no scale were 

 killed. 



Kerosene Emulsion (20 per cent oil). Same as for 25 per cent oil. 



Kerosene Emulsion (15 per cent oil). Trees sprayed in early May. 

 No benefits derived from this spraying. 



After these home-made remedies had proven so entirely unsatis- 

 factory, we determined to try all of the better known commercial 

 preparations during 1910. A number of home-made preparations 

 were also tried. Most of these mixtures have been previously recom- 

 mended for the San Jose scale, but had been abandoned for the 

 home-made lime-sulphur wash. These experiments were divided 

 into three groups. The first series of trees (I) were sprayed in late 

 December while the trees were dormant. The second series of trees 

 (II) were sprayed in late February while the sap was rising and just 

 when the buds were beginning to swell. The third series (III) were 

 sprayed in early May while most of the first brood of young were 

 crawling about or had just settled on the limbs. 



The results of these experiments are given herewith. 



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