PLANT RESPONSES TO INSECTICIDES IN THE SOIL 39 



to determine safe limits of use on the different soils for various 

 crops in the several States. It is especially important that these 

 studies be made in order to insure against the use of any per- 

 sistent substance to the extent that it causes a reduction in soil 

 productivity. 



It is similarly important to determine which new substances 

 can be used indefinitely with little or no danger of accumulating 

 harmful residues. The use of valuable and safe substances should 

 be encouraged. The commercial production of such substances 

 should be increased to permit an orderly replacement of persistent 

 toxic substances before trouble is encountered from too long con- 

 tinued use of the latter. 



LITERATURE CITED 



(1) Aguilar, J. d', and Grison, P. 



1948. ETUDE SUR LE PROBLEME DES TAUPINS EN BRETAGNE. Acad. 



d'Agr. de France Compt. Rendt. 34 : 261-267. 



(2) Albert, W. B. 



1933. arsenic toxicity in soils. S. C. Agr. Expt. Sta. Ann. Rpt. 

 46 : 44-45. 



(3) Allen, N., Bondy, F. F., Bullock, J. R., and others. 



1949. TWO YEARS' RESULTS OF EXPERIMENTS AT FLORENCE, S. C. ON 



TOLERANCE OF CERTAIN CROPS TO DDT, BENZENE HEXACHLORIDE, 



and toxaphene. U. S. Bur. Ent. and Plant Quar., 12 pp. 

 [Unpublished data.] 



(4) Blodgett, E. C. 



1941. A SYSTEMIC ARSENIC TOXICITY OF PEACH AND APRICOT ON OLD 



apple land. U. S. Bur. Plant Indus. Plant Dis. Rptr. 

 25 : 549-551. [Processed.] 



(5) BONNEMAISON, M. L. 



1947. ESSAIS PRELIMINAIRES DE TRAITEMENTS CONTRE LES TAUPINS. 



Acad. d'Agr. de France Compt. Rendt. 33 : 556-559. 



(6) Bourne, B. A. 



1948. EFFECTS OF BENZENE HEXACHLORIDE AND CHLORDANE ON THE 



GERMINATION OF SUGARCANE CUTTINGS. Sugar Jour. 10(8) : 



3, 4, 20. 



(7) Brooks, J. W., and Anderson, L. D. 



1947. toxicity tests of some new insecticides. Jour. Econ. Ent. 



40 : 220-228, illus. 



(8) Chapman, R. K., and Allen, T. C. 



1948. stimulation and suppression of some vegetable plants by 



ddt. Jour. Econ. Ent. 41 : 616-623, illus. 



(9) Chulski, K. 



1948. THE EFFECT OF BENZENE-HEXACHLORIDE ON SOME CROPS GROWN 



ON various soil types. Mich. Agr. Expt. Sta. Quar. Bui. 

 31 : 170-177. 



(10) Clausen, R., and Gunthart, E. 



1946. essai de lutte contre le ver blanc (melolontha melolon- 

 tha l.) avec l'hexachlorocyclohexane. Premier Cong. 

 Internatl. de Phytopharmacie. Pp. [289]-294. Heverlee, 

 Belgium. 



(11) Cooper, H. P., Paden, W. R., Hall, E. E., and others. 



1931. EFFECT OF CALCIUM ARSENATE ON THE PRODUCTIVITY OF CERTAIN 



SOIL types. S. C. Agr. Expt. Sta. Ann. Rpt. 44 : 28-36, illus. 



(12) Paden, W. R., Hall, E. E., and others. 



1932. SOILS DIFFER MARKEDLY IN THEIR RESPONSE TO ADDITIONS OF 



CALCIUM arsenate. S. C. Agr. Expt. Sta. Ann. Rpt. 45 : 23- 

 28, illus. 



(13) Fleming, W. E. 



1948. CHLORDAN FOR CONTROL OF JAPANESE BEETLE LARVAE. Jour. 



Econ. Ent. 41 : 905-912, illus. 



