THE NINETEENTH ANNUAL MEETING. 105 



poison liad had time to take effect, for we noticed the crescent mark on 

 some of the plums while spraying. The foliage of the plum trees was not 

 injured even by this strong mixture, but after the second spraying the 

 foliage of the cherry trees was somewhat burned, and after the third 

 spraying the injury was severe. 



"This year we repeated the experiments, but, owing to my unavoidable 

 absence from college just at the time the spraying should have been done, 

 the experiments were worthless, as far as killing the curculio was concerned, 

 though we obtained some interesting results in regard to the effect of the 

 arsenites upon foliage. 



EXPERIMENTS IN OHIO. 



"For definite practical results in fighting the curculio, we had best turn 

 to the work of the Ohio experiment station. Prof. Weed experimented 

 upon a small cherry orchard of seventy-five trees, the fruit of which had 

 previously been much injured by the curculio. One half of the trees were 

 sprayed three times with London jjurple, one pound to one hundred gallons 

 of water, with no injury to the foliage except on two trees, upon which 

 the liquid had been forced in a solid stream. The trees on the other half 

 of the orchard were left as checks. At picking time one thousand cherries 

 were taken from each of eight sprayed trees and seven thousand five 

 hundred were taken from seven of the check trees. Of the former only 

 three and one half per cent, were stung, while of the latter fourteen and 

 one half per cent, were stung. Prof. Weed therefore states that so far as 

 one experiment goes, it shows that seventy-five per cent, of the fruit on the 

 sprayed trees, liable to injury by plum curculio, was saved by the treat- 

 ment with London purple. In a bulletin lately received from Prof. Weed, 

 I find that he has repeated his experiments this year with practically the 

 same results. j 



" Prof. Weed's experiments upon the plum were not so extensive, but 

 seemed to give equally good results. Last year he sprayed plum trees four 

 times with London purple, one pound to one hundred gallons of water, 

 with some injury to foliage. He says: 'The fruit on all these trees was 

 almost free from injury, the limbs hanging so full that it was necessary 

 to artificially thin the fruit to prevent their breaking. The check trees, 

 unfortunately, did not set a full crop, but a large proportion of what did 

 set was injured by the curculio.' 



"This year Prof. Weed repeated the experiments on plums, except that 

 he used only one pound of London purple to one hundred and sixty gallons 

 of water, and added the Bordeaux mixture as a fungicide. No check trees 

 were left in the orchard, on account of the fruit-rot experiment, but two 

 plum trees on the grounds, a short distance from the orchard, were left 

 untouched. The latter set a good crop of fruit, but it was entirely ruined 

 by the curculio, not a single plum being left to mature. The crop in the 

 orchard, however, was immense, one half the fruit on many of the trees 

 being artificially thinned and still bearing so much that the limbs bent to 

 the ground and in some cases broke on account of the great weight. 



SUCCESS SEEMS ASSURED. 



"These experiments seem to show conclusively that the curculio can be 

 successfully combated with the arsenites. The questions now to consider 



14 



