-5- 



Percent oi' fruit stun>; 



25/5 Dieldrin w.p. 1 lb. -100 

 2^% Dieldrin w.p. l/2 lb. -100 

 Lead arsenate h. lbs. -100 

 Fungicide only 



.■yiOUNT NEEDED 



Drops 



U.58 



7.87 



1^0.02 



50.8$ 



Harvest 



1.39 



2.5I1 



18. 5U 



i+3. 87 



Totals 



3.95 

 5.16 



29.21; 



50.11 



The most practical concentration for dilute spraying seems to be one-fourth 

 pound of actual dieldrin in 100 gallons of water. This is obtained from one poimd 

 of 25^ wettable powder or from one-half pound of ^0% wettable powder. In many tests 

 twice this amount has been used, but in our experience it does not seem necessary. 



ADVANTAGES 



At the above strength, dieldrin should give effective control of plum curculio 

 at less cost than that of materials now used. It is also effective against plant 

 bugs and has reduced cat-facing injury to peaches appreciably. Preliminary studies 

 indicate that it is less destructive to beneficial insects than DDT or methoxychlor. 



DISADVANTAGES 



Dieldrin has not given effective control of most lepidopterous caterpillars. 

 Apparently it is necessary to add DDT, TDE to give satisfactory control of codling 

 moth and red-banded leaf roller on apples and Oriental fruit moth on peaches. On 

 apples it would be used with lead arsenate also. Dieldrin has a persistent residue. 

 It is poisonous to warm-blooded animals making it necessary for the operator to 

 wear protective clothing and respirator and to wash skin and clothing after 

 exposure. Spray drift must not be allowed to fall on grazing land or streams and 

 ponds . 



COMPATABILITY 



Dieldrin is compatible with most insecticides and fungicides usually used on 

 fruit trees except alkaline materials such as lime sulfur, Bordeaux mixture and 

 zinc sulf ate-lime . The new miticides, Ovotran and Aramite should not be combined 

 with it until further information is available. 



SUGGESTIONS FOR USE 



In 1953 the use of dieldrin is suggested on a trial basis only. On apples it 

 might be used in one of the three applications aimed at plum curculio, preferably 

 the First Cover Spray. Use 1/2 pound of 50^ wettable powder or 1 pound of 25^ 

 wettable povfder per 100 gallons v;ith the usual fungicides. DDT or TDE can be added 

 but they should not be necessary if methoxychlor is used in calyx and Second Cover 

 applications unless red-banded leaf roller is serious. 



It could be used with one-half strength lead arsenate or in place of lead in 

 the lead arsenate program (Schedule II) in the FIRST COVER SPRAY to give increased 

 protection against curculio. 



In peaches where the Shuck, First and Second Cover applications are critical 

 for curculio control, dieldrin may be used in any or all of the sprays but should 

 be combined with DDT to give protection against Oriental fruit moth. 



zr-il^-D . Viiliitcomb 



