72 JOURNAL OP ECONOMIC ENTOMOLOGY [Vol. 2 



neath the stamens. The outer calyx cup was washed free of spray 

 by the rain, which of course could not penetrate below, like our spray 

 driven at 200 pounds. 



7. "I would also call your aUention to another point, which per- 

 haps is not familiar to you, and that is, that in some of our varieties 

 it is simply impossihle to get the poison down to the bottom of the 

 calyx cup, because of the apple formation itself." 



Professor W. S. Thornber, horticulturist at the Washington Ex- 

 periment Station, has devoted many years to a comparative study of 

 the apple blossom, both in the Atlantic and the Pacific regions, and 

 he assures us that microscopic measurements show no differences in 

 structure induced by the change in environment. We have sprayed 

 nearly one thousand varieties of apples with unquestioned success, and 

 have yet noticed none of such conformation that the lower calyx 

 could not be effectively sprayed. 



It is true that the stamens are turgid and woolly and crowd against 

 the pistil, forming a tight barrier against a misty spray, but their 

 diverging free ends make a funnel-throat readily forced open by a 

 pressure-driven coarse spray, if that be squarely directed against the 

 flower, to spring shut again and enclose a drop of the liquid. This 

 probably is the secret why arsenate of lead will serve Avhen used as 

 weak as one pound to eighty gallons, or probably even much less, for 

 the drop carries with it enough poison amply to coat the interior of 

 the cavity when evaporated. Our criterion of thoroughness during 

 the first spraying is to section flowers picked at random to see if the 

 lower cup is filled with liquid. If any flowers are found dry beneath 

 the stamens of course the spraying is imperfect, and 100% returns 

 can not be expected from the single spraying. However, the lower 

 cup is always full when the tower-crook-Bordeaux nozzle, 200-pound 

 pressure method is used. 



8. "If I ran the pressure up, the blossoms capsized from the force 

 of the spray, and still the spray did not get into the lower cavity." 



A pressure-driven spray directed squarely will invariably be forced 

 past the stamens before the flower has a chance to tip over. Vermorel 

 nozzles, which throw a hollow cone of spray, rarely strike the blossoms 

 squarely, and therefore even if coarse are not capable of filling all 

 the lower cups. When Bordeaux spraying is done from the ground 

 the flowers are hit from the side and are thrown over by the force 

 of the spray without being effectively filled. 



9. "3Iost of otir orchardists use too coarse a spray anyway and one 



