

1948 - Watts, J. Gordon. Cotton insect control with organic insecticides. J. Econ. Ent. 

 41(4):543-547. 



In replicated plots and large-scale field tests, a dust mixture containing 5% 

 DDT and 3% gamma isomer was the most effective of 5 insecticide formulations 

 in increasing cotton yields. A 4.8% gamma isomer dust gave equal boll weevil 

 control, although yields were slightly, though not significantly, less. A 20% chlo- 

 rinated camphene ranked third in increasing cotton yields, but it was not signifi- 

 cantly better than calcium arsenate containing 1% nicotine. A proprietary boll 

 weevil spray which has been widely publicized and distributed failed to signifi- 

 cantly increase cotton yields over the untreated check. 



In preliminary tests on Grady sandy loam, a moderately heavy soil, 50% 

 DDT and 36% chlorinated camphene, applied to the soil at rates as high as 200 

 lbs. per acre at the time of seeding, caused no apparent injurious effects to any 

 of 19 crops. Similarly applied, 6% gamma isomer at 200 lbs. per acre caused 

 light to severe reduction in stands of all crops. At 100 lbs. per acre none of the 

 crops showed any apparent injury. It is significant that at all rates some of the 

 plants survived and appeared to mature in a normal manner. 



1948 - Young, M. T. Control of boll weevil and cotton aphid with benzene hexachloride 



and chlorinated camphene in 1947. J. Econ. Ent. 41(3) :40 1 -403. 



Treatments with (1) benzene hexachloride, (2) chlorinated camphene, (3) al- 

 ternate applications of a nicotine -calcium arsenate mixture and calcium arsenate, 

 and (4) calcium arsenate alone were all equally effective against the boll weevil 

 and the cotton aphid, whether applied early in the morning or late in the after- 

 noon. 



Three benzene hexachloride dusts, 5.0%, 2.5% and 1 .25% gamma isomer, were 

 more effective against both the boll weevil and the cotton aphid and caused a 

 greater increase in yield when applied at 4- or 5 -day intervals than when applied 

 at 7- to 9-day intervals. Benzene hexachloride dusts containing 5% and 2.5% of 

 the gamma isomer gave boll weevil control equal to that of calcium arsenate or 

 alternate applications of the calcium arsenate -nicotine mixture and calcium 

 arsenate, but yields were less. 



Dusts containing 20% and 10% of chlorinated camphene were more effective 

 against the boll weevil and the cotton aphid and yielded better when applied at 

 4- or 5 -day intervals than when applied at 7- to 9 -day intervals. However, neither 

 the boll weevil control nor the yields from any of the chlorinated camphene dusts 

 were as good as those from either calcium arsenate or alternate applications of 

 the calcium arsenate -nicotine mixture and calcium arsenate. 



Five applications of calcium arsenate plus 1 application of benzene hexachlo- 

 ride (5% of gamma isomer) gave better boll weevil control and a greater yield 

 than alternate applications of the calcium arsenate -nicotine mixture and calcium 

 arsenate. Benzene hexachloride mixture containing 5% of the gamma isomer, 

 when used as a separate application with calcium arsenate in the boll weevil 

 control program, gave better aphid control than 20% chlorinated camphene used 

 in a similar way in the calcium arsenate program. Both benzene hexachloride and 

 the chlorinated camphene permitted an increase of two-spotted spider mites. 



1949 - Fife, L. C., R. L. Walker, Jr., and Floyd F. Bondy. Boll weevil control with 



several organic insecticides during 1948. J. Econ. Ent. 42(4):682-684. 



Dusts containing 2% and 3% of the gamma isomer of benzene hexachloride 

 plus 5% of DDT gave the best boll weevil control and the highest yields. A mix- 

 ture containing 1% of the gamma isomer plus 5% or 10% DDT was not strong 

 enough to give good weevil control. Toxaphene and chlordan at 10% strength plus 

 5% of DDT were about equal in controlling the boll weevil and increasing the 

 yield, but they were less effective than a benzene hexachloride dust containing 

 either 2% or 3% of the gamma isomer. Twenty percent of chlordan gave better 

 boll weevil control and a higher yield than did 10%. The addition of 5% of DDT to 

 10% of chlordan did not increase the boll weevil control, but it increased the 

 yield, probably owing to additional control of other injurious insects. Moreover, 

 the addition of 1% of parathion or 1% of rotenone to the latter mixture gave 



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