APPLE SPRAYING EXPERIMENTS IN I915. 171 



Plot 5 was a continuation of previous work, the object being 

 to test the fungicidal properties of arsenate of lead in control- 

 ling apple scab. 



Plot 6 was a repetition of an experiment conducted the pre- 

 vious year. 



Plot 8 was introduced largely to determine how much injury 

 might be expected from the application of dormant strength 

 lime-sulphur after the leaf buds had begun to open, or at a later 

 period than it is customary to use this material. It has been 

 demonstrated previously at this station, where young Mcintosh 

 trees showed an abundance of limb infection from the season 

 before, that a dormant strength lime-sulphur applied just as the 

 leaf buds were swelling, but. before they opened, materially 

 reduced the amount of scab on the leaves the following sum- 

 mer.* While, as far as the writer is aware, so long a delay in 

 applying the dormant strength lime-sulphur has been advised 

 or recommended by no one, even for limb infection for apple 

 scab, the Station receives numerous inquiries each year as to 

 whether or not it may be done with safety. These usually come 

 from orchard owners who have purchased materials in order 

 to spray for blister mite, scale insects, etc., but who, for one 

 reason or another, have failed to do so at the proper time. 



Time and Manner op Spray Applications. 



All the sprays were applied with a gasoline power sprayer 

 at a pressure of from 150 to 200 pounds per square inch, 

 using a nozzle which delivered a fine mist. Especial care was 

 taken to see that each tree was thoroughly covered with the 

 spray at each application, but not enough material was applied 

 to cause excessive dripping. After each plot was sprayed the 

 spray tank, pump, hose and extension rods were thoroughly 

 rinsed in clean water. 



The dormant spray on plot 8 was applied on May 3. At 

 this time the blossom buds appeared well protected. The 

 young leaves surrounding them were not over one-third of an 

 inch long, frequently less, and closely imbricated. 



*Morse, W. J., and Darrow, W. H. Is apple scab on young shoots a 

 source of spring infection? Phytopathology 3:265-269, Oct., 1913. 



Morse, W. J. Spraying experiments and apple diseases in 1913. Bui. 

 Me. Agr. Exp. Sta. 223 :20-23, Jan., 1914. 



