บทคัดย่องานวิจัย

หมวดหมู่ : ฐานข้อมูลงานวิจัย

The efficacy of linalool, a major component of freshly-milled Ocimum canum Sims (Lamiaceae), for protection against postharvest damage by certain stored product Coleoptera

David K. Weaver, Florence V. Dunkel, Leopold Ntezurubanza, Larry L. Jackson and Darrell T. Stock

Journal of Stored Products Research Year: 1991 Vol: 27 Issue: 4 Pages: 213-220

1991

บทคัดย่อ

The efficacy of linalool, a major component of freshly-milled Ocimum canum Sims (Lamiaceae), for protection against postharvest damage by certain stored product Coleoptera.

Linalool was present at 8.6 plus or minus 0.9 mg/g in dried leaves of Ocimum canum [O. americanum], an annual mint used in Rwanda to protect against postharvest insect damage. Direct exposure of adults of the bruchid Zabrotes subfasciatus to milled, dried O. canum leaves resulted in 100% mortality of males and 50% mortality of females after 48 h. Dose-response curves for linalool were obtained for adult Z. subfasciatus, Acanthoscelides obtectus, Rhyzopertha dominica and Sitophilus oryzae using a filter paper bioassay, and LC50 values were 428, 405, 428 and 427 micro g/cm2, resp. Knockdown was occasionally followed by recovery at doses less than the LC50 for all species. There were significant differences in the LC50 and LT50 values for male and female Z. subfasciatus. At lower doses, hyperactivity rarely preceded moribundity and mortality where these occurred, while at higher doses hyperactivity occurred soon after initial exposure and preceded imminent death. A concn increase from 250 to 750 micro g/cm2 spanned the 10-100% response mortality for all species at 24 h. Air-exposure of linalool-treated papers (500 micro g/cm2) for up to 24 h significantly decreased toxicity to both sexes of Z. subfasciatus. Quantitative analysis showed the only significant decrease in the amount of linalool to occur after 0.25 h, and that this did not fully correlate with the resulting decrease in efficacy against both sexes of Z. subfasciatus. The results are discussed in terms of the efficacy of using O. americanum for the protection against loss due to insects in the traditional food storage systems of Rwanda.