21 



^fr. I"^i-(Micli st;il<'<l llial a fiuil uiowcr near ( 'arboiMlalc, 111., lia<l 

 been in llic liahil of spfayiiii; his apitlc trees ci^lit t imcs (Imiiiix lh«^ 

 season with wliit(> arsenic and soda (eai'bonate of soda), and for tlio 

 past fonr years liad found only an oecasional wormy a])ple. Some 

 t rees of the Winesap variety were sprayed last summer ei<;hl times 

 with arsi'iiatf of lead, usinjjc •> pounds to 50 <;allons of water, and the 

 Irnil on these trees was one-fourth to one-half small'^r than that on 

 the trees treated with the other material. 



.Mr. Sanderson thouglit that this niiglit l»e due to the fact that 

 ai-seiuite of lead would adhere better to the finiit, and that the ti'ces 

 had Iteeii oversprayed. lie also spoke of the necessity' of making 

 accurate counts of all the wormy fruit and taking into consideration 

 tlie ai)ples that di'()i)ped to the ground early in the season, as well as 

 those found on the trees at the time of picking, and gave the follow- 

 ing summaiy of his experiments in Delaware: 



(1) Arsenate of lead (di-spjirene), 1 pound to 50 j^allons. f?ives from one-third to 

 one-half more in perfect picked frnit than arsenites of lime or soda, Paris j^reen, 

 or green arsenoid. 



(2) Paris Krc«'n or }^re(>n arsenoid, 1 pound to IGO gallons, and arsenites of lime 

 or soda. 1 gallon to Kill gallons, are j)ractically of eiiual value. 



(3) The addition of move arsenite than the above strength is unwarranted. 



(4) Spraying three times does not give enough benefit to warrant the third 

 spraying if the first two are properly made. 



(.")) It is doul)tful whether the addition of adliesives is profitable. 



(6) The addition of 1.") per cent or 20 per cent loO-test kerosene is not deleterious 

 to the insecticidal value of the arsenite or the fungicidal value of the Bordeaux 

 mixture, but the same .strength of crude petroleum can not be recommended for 

 use when spraying for the codling moth. 



( 7 ) A lienefit of from 2.5 to 75 per cent is derived from spraying as regards the 

 amount of fruit dropjjed. varying with the season and spray. 



(5) Thel»ent^fit derived from spraying increases in direct ratio as the per cent 

 of dropped fruit and the percenr of wormy fruit on unsprayed trees. (Thus with 

 .5ri and 00 ])er cent wormy fruit and fill and 50 per cent dropped in 1!)02 ami lllOl, 

 respectively, on Winesaps. there was 112 to tSU per cent l)enefit to the perfect 

 jticked fruit sprayed with disparene; 70 and S7 p m" cent ^^•ith ar.senites of .soda and 

 lime in 1902, and 120 per cent with Paris green in 1001: while with an average of 

 25 per cent wormy dropped on Stark and Nero in 1002 then* was but :$() to ;{7 per 

 cent benefit to perfect picked fruit.) 



(9) In the .'■ame ordiard and variety the per cent of perfect fruit drop])ing is 

 practically the s;une whether sprayed or unsprayed. the amount of dropi>ed frnit 

 depending upon the percentage of dropjiings wonny. 



(10) The ])enefit derived from the spraying lies in increasing the amount of 

 picked fruit and decreasing tlie amount of wormy droppings, and only partly in 

 decreasing the perccTitage of wormy jjicked frnit. 



Mr. Piper suggested that all the fruit that di-ojjped must not be 

 considered as loss, because in many seasons the fruit on the trees 

 should be thiniu'<l in order to j>r(»duce a lai'ge and perfect crop. 



Mr. Cooley agreed with .Mr. Piper on thisjtoint and stated furlhei- 

 thai in .Montana the pi'oblem for conl rolling t he codling mol h was lo 



