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Persistence of Insecticides on Cotton and Maize
Author(s) -
ElSebae A. H.,
ElSayed Arafat M. K.
Publication year - 1969
Publication title -
zeitschrift für angewandte entomologie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.795
H-Index - 60
eISSN - 1439-0418
pISSN - 0044-2240
DOI - 10.1111/j.1439-0418.1969.tb03050.x
Subject(s) - endrin , relative humidity , persistence (discontinuity) , limiting , toxicology , carbaryl , biology , agronomy , lepidoptera genitalia , bioassay , zoology , chemistry , pesticide , botany , organochlorine pesticide , ecology , mechanical engineering , physics , geotechnical engineering , engineering , thermodynamics
Summary Dipterex, Endrin, and Sevin are recommended as sprays on cotton plants to control lepidopterous pests especially the cotton leaf worm and the boll worms. Such treatments are recommended mainly for protective purposes, therefore the duration and persistence of the residual toxicity of such insecticidal deposits on the cotton foliage is a limiting factor in evaluating its efficiency under field conditions. This study was planned to measure the persistence of these insecticides on cotton. In addition, DDT is recommended to control the corn borers, thus the persistence of DDT on corn plants was included in this work. The micro‐bioassay technique for assaying these insecticides was adopted to determine the residual toxicity. The dry film left from acetone wash aliquot was subjected to the beetles of Tribolium confusum under standardized conditions. The residue half lifes RL 50 of Dipterex, Endrin, and Sevin on cotton vere: less than one day, 1–1.2, and 2.6–3.8 days respectively, while the RL 50 of DDT on corn plants was 4.3 days. The recorded climatic temperature and relative humidity was used in interpretation of the variation of the loss in residues in the successive sprays. It was concluded that rise in climatic temperature or relative humidity will increase the rate of loss of residues on foliage. However, relative humidity variation seems to be the limiting factor in dissipation of insecticide residues. Zusammenfassung Auf Baumwolle werden Dipterex, Endrin und Sevin gegen Lepidoptera‐Schädlinge empfohlen . Die Bestimmung der Rückstandsmengen dieser Insektizide auf Baumwolle und der Rückstandsmengen von DDT auf Mais wurden durch den Biotest mit Hilfe der Adulten von Tribolium confusum bestimmt. Die Halbwertzeit (RL 50) von Dipterex, Endrin und Sevin auf Baumvolle betrug weniger als einen Tag, beziehungsweise 1–1, 2 und 2, 6–3, 8 Tage. Auf Mais betrug sie bei DDT 4, 3 Tage. Die Ergebnisse zeigten auch, daß die Steigerung der Lufttemperatur oder der relativen Luftfeuchtigkeit die Rückstände schneller zersetzen läßt. Jedoch scheinen die Schwankungen der relativen Luftfeuchtigkeit der begrenzende Faktor in der Zersetzung der Insektizid‐Rückstände zu sein.