' 



1937 - Gaines, R. C. Tests for boll weevil control using Latin square plot arrangement, 

 Tallulah, Louisiana. J. Econ. Ent. 30(6):845-848. 



Experiments on the control of Anthonomus grandis Boh. with calcium ar- 

 senate dusts were made in Louisiana in 1936, using the Latin square arrange- 

 ment. The plots, 4 of which were left untreated, 4 treated with calcium arsenate, 

 4 with calcium and lime (50:50) and 4 with calcium arsenate and sulphur (50:50) 

 were artificially infested. Treatment of 7 lbs. per acre was begun on the 28th of 

 July and continued at intervals of about 4 days until the 26th of August. On the 

 27th of July, the average percentages of punctured squares on the 4 groups of 

 plots were 12.9%, 14.6%, 17.5%, and 14.4%, respectively. On the 10th of August, 

 they were 50.4%, 16.9%, 25.4%, and 23.9%. Conditions were favorable to the in- 

 crease of the weevils during July, but very unfavorable during August and Sep- 

 tember. There were considerably more blooms and bolls on all the treated plots 

 than on the control plots, slightly more on those that received calcium arsenate 

 and sulphur than on those that received calcium arsenate and lime, and most on 

 those that received calcium arsenate alone. The height of the plants and the num- 

 ber of plants per acre were very uniform. The data on yield were analyzed by the 

 method of analysis of variance. The plots treated with calcium arsenate, calcium 

 arsenate and sulphur, and calcium arsenate and lime produced respectively 10.9%, 

 9.3%, and 6.9% more than the controls. All these differences were significant, but 

 there was no significant difference in control between any two of the calcium ar- 

 senate treatments. 



1937 - Smith, G. L. , and A. L. Scales. Toxicity of a number of insecticides to three 

 cotton insects. J. Econ. Ent. 30(6):864-869. 



The following is substantially the authors' summary of dusting tests made in 

 Louisiana in 1936 with various insecticides: Against Anthonomus grandis Boh., 

 calcium arsenate was more effective than any of the insecticides tested, with the 

 exception of cube (4.9% rotenone), Paris green, and mixtures of calcium arsenate 

 and Paris green. 



1937 - Strong, L. A. Report of the Chief of the Bureau of Entomology and Plant Quaran- 



tine, 1937. U. S. D. A., 98 p. Wash. 



In connection with work on the cotton boll weevil, a survey is given of ob- 

 servations in various states on the effect of calcium arsenate on the soil. Con- 

 tinued applications on the Delta soil of Louisiana and Mississippi have not 

 affected cotton production in any way, but excessive quantities were injurious 

 to soybeans and cowpeas. In South Carolina, injury was most noticeable in light 

 sandy soils of low fertility where abnormally large amounts had been applied. 

 In Mississippi, the effect on different crops varied considerably with the soil 

 types. Defoliation of the mature plants resulted in a great reduction of overwin- 

 tering population of Anthonomus grandis. In tests carried out in August in Mis- 

 sissippi, dusting increased the yield by 288 lbs. of seed cotton per acre, this 

 being due partly to the development of heavier bolls on plants that had not been 

 defoliated. 



1938 - Ewing, K. P., and R. L. McGarr. Sulfur and calcium arsenate for the Control of 



the cotton flea hopper and the boll weevil. J. Econ. Ent. 31(6):669-674. 



Mixtures of calcium arsenate and sulfur, 1:1, 1:2, and 1:4 proportions, were 

 tested in 1-acre field-plot experiments along with sulfur for cotton flea hopper 

 control and with calcium arsenate for boll weevil control. The infestation records 

 and bloom counts showed that the mixtures gave slightly better flea hopper con- 

 trol than the sulfur, but the difference was not great enough to overcome the ex- 

 perimental error between the plots or show consistent gains in yield. In the 

 1-acre experiments for boll weevil control, the bloom counts and yield records 

 showed that the addition of sulfur to calcium arsenate, when the minimum aver- 

 age poundage of calcium arsenate was not below 4.66 lbs. per acre application 

 (1:2 and 1:1 mixtures of calcium arsenate and sulfur), increased the fruiting and 

 also the production of the cotton over that of calcium arsenate alone when used at 

 the rate of 6.68 lbs. per acre application. The net profit was also greater from 



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