Emilie Deletre1, Fabrice Chandre2, Barbara Barkman1, Chantal Menut3, Thibaud Martin1,4. 1. UR Hortsys, Cirad, Campus de Baillarguet, Montferrier, France. 2. UMR MiVEGEC, IRD-CNRS-UM1-UM2, Monferrier, France. 3. Institut des Biomolécules Max Mousseron, Faculté de Pharmacie, Montpellier, France. 4. Plant Health Department, ICIPE, Nairobi, Kenya.
Abstract
BACKGROUND: In tropical countries, netting is an effective sustainable tool for protecting horticultural crops against Lepidoptera, although not against small pests such as Bemisia tabaci, while smaller mesh netting can be used in temperate regions. A solution is to combine a net with a repellent. Previously we identified repellent essential oils: lemongrass (Cymbopogon citratus), cinnamon (Cinnamomum zeylanicum), cumin (Cuminum cyminum) and citronella (Cymbopogon winternarius). The present study was designed to identify the active compounds of these essential oils, characterise their biological activity and examine their potential for coating nets. We investigated the efficiency and toxicity of nets dipped in different solutions. We then studied the repellent effect with an olfactometer and the irritant effect by videotracking. RESULTS: Geraniol and citronellol were the most promising net coatings owing to their repellent effect. The repellency, irritancy or toxicity varied with the product and concentration, and these features were independent, indicating that the repellent and the irritant/toxic mechanisms were not the same. The combined effects of these different compounds account for the bioactivity of the mixture, suggesting interactions between the compounds. CONCLUSION: This new sustainable strategy for protecting vegetable crops against whiteflies is discussed, in addition to the use of companion plants that could produce such bioactive compounds.
BACKGROUND: In tropical countries, netting is an effective sustainable tool for protecting horticultural crops against Lepidoptera, although not against small pests such as Bemisia tabaci, while smaller mesh netting can be used in temperate regions. A solution is to combine a net with a repellent. Previously we identified repellent essential oils: lemongrass (Cymbopogon citratus), cinnamon (Cinnamomum zeylanicum), cumin (Cuminum cyminum) and citronella (Cymbopogon winternarius). The present study was designed to identify the active compounds of these essential oils, characterise their biological activity and examine their potential for coating nets. We investigated the efficiency and toxicity of nets dipped in different solutions. We then studied the repellent effect with an olfactometer and the irritant effect by videotracking. RESULTS:Geraniol and citronellol were the most promising net coatings owing to their repellent effect. The repellency, irritancy or toxicity varied with the product and concentration, and these features were independent, indicating that the repellent and the irritant/toxic mechanisms were not the same. The combined effects of these different compounds account for the bioactivity of the mixture, suggesting interactions between the compounds. CONCLUSION: This new sustainable strategy for protecting vegetable crops against whiteflies is discussed, in addition to the use of companion plants that could produce such bioactive compounds.
Authors: Tao Wang; Yanling Ren; Jinyu Zhao; Yao Liu; Bin Xu; Maofa Yang; Wanling Zhao; Xinian Zheng; Juan Wang; Liuqiong Deng Journal: Front Chem Date: 2022-06-29 Impact factor: 5.545
Authors: Elhadi E Elamir; Abdulrhman A Almadiy; Gomah E Nenaah; Abdullah A Alabas; Hajer S Alsaqri Journal: Bioengineered Date: 2019-12 Impact factor: 3.269