THE NINETEENTH ANNUAL MEETEs'G. 107 



purple, but should never use it stronger than one pound to one hundred 

 and tixty gallons of water; fourth, if we use the arsenites on peach trees, 

 use Paris green not stronger than one pound to two hundi'ed and tifty or 

 three hundred gallons of water. 



"The question now arises, will these strengths be effective? Prof. 

 Forbes has fouml, in some breeding-cage experiments, that four days after 

 spraying foliage with Paris green in various proportions, the results were 

 as follows: One pound to one hundred gallons of water killed forty-eight 

 per cent, of the beetles, one pound to two hundred gallons killed thirty- 

 three per cent., one pound to three hundred gallons killed twenty-seven 

 per cent., and one pound to five hundred gallons killed eighteen per cent. 

 From these residts we may infer that, proWding we can be equally success- 

 ful on a large scale, Paris green in as weak a mixture as one pound to 

 three hundred gallons of water may be advantageously used to poison the 

 curculio, and we believe so weak a mixture will not injure the foliage of 

 any tree, not even of the peach. In spraying pear, plum, apple, and 

 cherry trees, a much stronger, and hence a much more effective, mixture 

 may \ye used. Probably, however, one pound of Paris green to two hun- 

 dred gallons of water will be found strong enough for all purposes. Mr. 

 Payne of South Haven found that, forty-eight hours after using Paris 

 green in this proportion, on jarring the treps threefourths of the curculio 

 that fell were dead. 



WHEN TO SPRAY. 



"When shall we spray? Prof. Osborn of Iowa, after conducting some 

 experiments in poisoning the curculio, says: 'They show, if an\'tliing, 

 that the insects are able to continue their work for some days after having 

 fed upon ix)isoued fruit.' Other experimeutei-s have come to practically 

 the same conclusion. We must, therefore, spray as early as possible; for, 

 if the insects are able to live several days after being poisoned, they may 

 do much damage after the spraying. Of course we must not spray before 

 the blossoms fall, unless we spray before they appear, or we will kill the 

 bees, and bees are great aids to fruitgrowing; but the sooner we spray 

 after the blossoms fall the better. It is evident that if we can kill a large 

 proportion of the insects before the fruit is large enough for them to 

 attack, the battle will be won. 



'• In closing, let me say that a great many carefully conducted experi- 

 ments will yet have to be made before we can satisfactorily answer many 

 of the questions relating to this subject. I hope to be able to conduct 

 some of them next spring, and hope you will all aid in the work. It will 

 be a benefit to the state, and to each of you personally, if you will all care- 

 fully conduct experiments upon this subject and forward the results to the 

 experiment station. There the results can be compiled and sent out in 

 the form of a bulletin, thus reaching a much greater number of fruit- 

 gi'owers than would be the case if each one were to conduct his experi- 

 ments independently and publish the residts only through the medium 

 of his local society." 



PROF. L. H. BAILEY ON SPRAYING. 



Following this. Secretary Reid read a paper by Prof. L. H. Bailey of 

 Corufll university, on the same subject, which is here subjoined in full: 



