APPLE SPRAYING EXPERIMENTS IN I914. 179 



Plot 9. Extra fine sulphur lo pounds plus one pound of dry 



arsenate of lead in 50 gallons of water. 

 Plot 10. Lime-sulphur 20 per cent stronger than standard dilu- 

 tion plus one pound of dry arsenate of lead in 50 

 gallons. 

 Plot II. Two pounds of dry arsenate of lead alone in 50 gallons 



of water. 

 Plot 12. Unsprayed check. 



Plots I, 4, and 12, sprayed with bordeaux mixture, standard 

 dilution lime-sulphur, and unsprayed, respectively, were intro- 

 duced as checks upon which to make comparisons in judging 

 the results obtained upon the other plots. 



The spraying program laid out for plots 2, 3, and 1 1 was sug- 

 gested by the results obtained with arsenate of lead as a fungi- 

 cide during the two previous seasons.* The efficiency of this 

 material in controlling apple scab, when used somewhat in 

 excess of the usual amount employed as an insecticide, sug^ 

 gested a possible modification in spraying procedure which might 

 still control both scab and insect enemies and at the same time 

 simplify the work of orchard spraying. This plan was to use a 

 strong fungicidal spray combined with the usual amount of 

 arsenate of lead when the blossom buds are showing pink, but 

 for later sprayings to depend entirely upon double strength 

 arsenate of lead alone for controlling both scab and insect 

 enemies. Plot 11, sprayed with arsenate of lead alone throuj^'h- 

 out the season, was introduced in order to obtain additional data 

 upon the fungicidal value of this material. 



Plots 5 and 10 were primarily for comparison with plot 4 

 which was sprayed 3 times with standard dilution lime-sulphur. 

 It is generally conceded that the application of fungicides when 

 the blossom buds are showing pink is a very important one from 

 the standpoint of scab control. Partly through accident this 

 was brought out quite forcibly in the 1912 experiments. On 

 the other hand omitting this first application of lime-sulphur irt 

 1 91 3 resulted in but a slight increase of scab. Hence plot 5 was 

 introduced into the 1914 experiments to test this matter again in 



*Moirse, W. J. and Yeaton, G. A. Orchard Spraying Experiments in 

 1912. Maine Agl. Exp. Sta. Bui. 212: 69-70. 1913. 



Morse, W. J. Spraying Experiments and Studies on Certain Apple 

 Diseases in 1913. Maine Agl. Exp. Sta. Bui. 223 : 13-16. 1914. 

 2 



