36 NEW YORK STATE MUSEUM 



may be screwed to it at an angle of about 45° from the hori-. 

 zontal, thus obviating in large measure the tendency of the hose 

 to break at the end of the. coupling, owing to its hanging there- 

 from at a nearly right angle. High poiwer outfits capable of de- 

 veloping 200 pounds pressure are being used in the gipsy moth 

 work, with a solid stream nozzle, experience showing that on 

 high trees at least, a very fair spray is secured under such con- 

 ditions. This method could probably be used to advantage on 

 large orchard trees. 



Methods. There has been more or less difference of opinion 

 as to the relative efficacy of a coarse or fine spray in work 

 against the codling moth. This has culminated in recent years 

 in some very strong statements made in favor of employing a 

 rather coarse spray and an unusually high pressure in an eft'ort 

 to drive the poison into the lower calyx cavity, that is the cavity 

 below the stamens. It is hardly necessary to remind fruit grow- 

 ers that after the white petals haA^e dropped we have the green 

 calyx lobes and Avithin a ring of numerous upright, slender 

 stamens surrounding the central, fleshy pistil. , Below the 

 stamens and at the base of the pistil there is an appreciable 

 cavity [pi. 19, fig. i]. This is the place, according to some authors, 

 where the poison must be put if we would obtain fairly satisfactory 

 results. One writer has even gone so far as to state that if spraying 

 is not done in this manner the small apple worm is fairly safe, 

 since it rarely feeds before it goes down into the lower cup, and 

 that the poison sprayed on the outside will therefore not affect 

 it. The claims for this method of spraying were so strong that 

 the problem seemed one worthy of careful, demonstration, and 

 the writer therefore planned and conducted a series of experi- 

 ments for the purpose of obtaining data upon this proposition. 



Experimental work. The main purpose of these experiments 

 was to test the relative efficiency of a coarse driving spray, such as 

 that produced by a typical Bordeaux nozzle with a pressure of over 

 100 pounds in comparison with the fine, misty spray of the Ver- 

 morel nozzle and its various modifications so extensively used in 

 the eastern United States. 



Comparisons were made between single sprays of each of 

 the above mentioned kinds applied just after the blossoms fell, 

 between two sprays of each kind, one given just after the blos- 

 soms fell and the second just before the sepals closed and 

 finally, between two such sprays and a third applied with a 



