108 MAINE STATE COLLEGE 



In general it is safe to say the proper time for the first applica- 

 tion is just after the fruit has formed ; and for the second, some 

 two or three weeks later. In no case should any spraying be done 

 while the trees are in blossom. It is too early to be of any value 

 whatever in checking the work of the codling larvae, and very 

 serious damage may be done in poisoning the bees, which are very 

 abundant at that season. 



7. Work in Other States. As early as 1880, Professor A. J. 

 Cook, of the Michigan Agricultural College, commenced the use of 

 the arsenites in combatting the codling moth and other orchard 

 pests. He has been an earnest advocate of spraying ever since, 

 and has done much to bring the practise into popular favor in the 

 West. 



Professor E. S. Goff in 1884, conducted a series of experiments 

 at the New York Agricultural Experiment Station, in which he 

 found that 69 per cent, of injury was prevented by the use of 

 Paris green. Similar results were obtained by Dr. S. A. Forbes, 

 of Illinois, in 1885. 



In 1889, Professor C. P. Gillette sprayed four Duchess trees 

 with London purple, taking four contiguous trees as checks. "At 

 the end of the season it was found that the treated trees had 68 

 per cent, less of wormy fruit than those not treated."* 



Professor Gillette also tried a new method of applying poison 

 to the trees. His method was the same as that used by many 

 farmers in treating potato vines for the Colorado beetle, i. e. mix 

 1 pound Paris green with 100 pounds land plaster and throw the 

 mixture over the trees when the dew is on. This method is of 

 course impracticable for use in a large orchard, and is suggested 

 only as a possible expedient for saving the fruit on a few trees 

 about the house. 



Professor Beckwith (Bui. XII, Del. Exp. Sta.) found that: 

 "The percentage of wormy fruit from trees sprayed with either 

 London purple or Paris green was from 18 to 35 per cent, less 

 than from trees not sprayed. The greatest benefit was obtained 

 when the trees were sprayed three times, using the mixture at the 

 rate of 1 pound to 200 gallons of water." 



These results are at variance with those obtained by Gillette, 

 who found that : "There was practically no difference between 

 once and twice spraying ;" and "No. 7, which was treated late, 



* Bulletin 7, Iowa Experiment Station. 



