[ Effets de l’huile de Thevetia et de Top bio sur les pucerons et leurs prédateurs en culture cotonnière biologique à Gobé au Centre du Bénin ]
Volume 39, Issue 4, June 2023, Pages 1726–1738
Saturnin Azonkpin1
1 Institut de Recherche sur le Coton, Antenne Régionale Sud, Laboratoire d’Entomologie de Cana, BP: 143 BOHICON, Benin
Original language: French
Copyright © 2023 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Insect pests are a major constraint to cotton production. In order to find an alternative to chemical control of Aphis gossypii, the insecticidal effect of Thevetia oil and Top bio (based on neem seeds), was evaluated in the field on cotton aphids and their predators in Benin. Thevetia oil at 0.1 and 0.2 liters per hectare and Top bio at 2 and 3 liters per hectare were tested in comparison with the agri-bio-pesticide used by organic cotton farmers at the rate of one liter per hectare and an absolute control (untreated) in a Fisher block design. The agri-bio-pesticide was derived from neem seeds, indigenous «koto» soap and pili-pili pepper. Observations and measurements focused on the population level of A. gossypii and its predators and then on yield. The results obtained revealed that thevetia oil and Top bio significantly (p<0.05) reduced aphid damage on cotton at their low dose. Cotton plots treated with 1% Thevetia oil had more ladybugs (0.09±0.016) than those treated with Top bio at 2 l/ha (0.02±0.016). Agri-bio-pesticide and Top bio at 2 l/ha reduced the number of ladybirds compared to the «Untreated», while Thevetia oil did not. Thevetia oil and Top bio did not reduce the number of spiders compared to Agri-bio-pesticide and «Untreated». Biopesticides did not reduce the number of ladybugs and ants compared to the «Untreated». These predators can be used effectively as biological control agents in an integrated pest management strategy for cotton using these biopesticides.
Author Keywords: Integrated Management, Aphis gossypii, Predators, Botanical insecticides, Organic Cotton.
Volume 39, Issue 4, June 2023, Pages 1726–1738
Saturnin Azonkpin1
1 Institut de Recherche sur le Coton, Antenne Régionale Sud, Laboratoire d’Entomologie de Cana, BP: 143 BOHICON, Benin
Original language: French
Copyright © 2023 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Insect pests are a major constraint to cotton production. In order to find an alternative to chemical control of Aphis gossypii, the insecticidal effect of Thevetia oil and Top bio (based on neem seeds), was evaluated in the field on cotton aphids and their predators in Benin. Thevetia oil at 0.1 and 0.2 liters per hectare and Top bio at 2 and 3 liters per hectare were tested in comparison with the agri-bio-pesticide used by organic cotton farmers at the rate of one liter per hectare and an absolute control (untreated) in a Fisher block design. The agri-bio-pesticide was derived from neem seeds, indigenous «koto» soap and pili-pili pepper. Observations and measurements focused on the population level of A. gossypii and its predators and then on yield. The results obtained revealed that thevetia oil and Top bio significantly (p<0.05) reduced aphid damage on cotton at their low dose. Cotton plots treated with 1% Thevetia oil had more ladybugs (0.09±0.016) than those treated with Top bio at 2 l/ha (0.02±0.016). Agri-bio-pesticide and Top bio at 2 l/ha reduced the number of ladybirds compared to the «Untreated», while Thevetia oil did not. Thevetia oil and Top bio did not reduce the number of spiders compared to Agri-bio-pesticide and «Untreated». Biopesticides did not reduce the number of ladybugs and ants compared to the «Untreated». These predators can be used effectively as biological control agents in an integrated pest management strategy for cotton using these biopesticides.
Author Keywords: Integrated Management, Aphis gossypii, Predators, Botanical insecticides, Organic Cotton.
Abstract: (french)
Les insectes ravageurs constituent une contrainte majeure à la production du cotonnier. En vue de trouver une alternative à la lutte chimique contre Aphis gossypii, l’effet insecticide de l’huile de Thevetia et de Top bio (à base de graines de neem), a été évalué au champ sur les pucerons du cotonnier et leurs prédateurs au Bénin. L’huile de Thevetia dosé à 0,1 et 0,2 litre à l’hectare et le Top bio dosé à 2 et 3 litres à l’hectare ont été testés en comparaison avec l’agri-bio-pesticide utilisé par les producteurs de coton biologique à la dose d’un litre à l’hectare et un témoin absolu (non traité) dans un dispositif en bloc de Fisher. L’agri-bio-pesticide provient des graines de neem, du savon indigène «koto» et du piment pili-pili. Les observations et mesures ont porté principalement sur le niveau des populations de A. gossypii et de ses prédateurs puis sur le rendement. Les résultats obtenus ont révélé que l’huile de Thevetia et le Top bio ont permis de réduire significativement (p<0.05) les dégâts causés par les pucerons sur le cotonnier à leur faible dose. Les parcelles de cotonniers, traitées avec l’huile de Thevetia dosée à 1%, ont hébergé plus de coccinelles (0,09±0,016) que celles traitées avec Top bio dosé à 2 l/ha (0,02±0,016). L’Agri-bio-pesticide et le Top bio dosé à 2 l/ha ont réduit le nombre de Chrysopes par rapport au «Non traité» contrairement à l’huile de Thevetia. L’huile de Thevetia et le Top bio n’ont pas réduit le nombre d’araignées par rapport à l’Agri-bio-pesticide et le «Non traité». Les biopesticides n’ont pas réduit le nombre de coccinelles et de fourmis par rapport au «Non traité». Ces prédateurs peuvent être utilisés efficacement comme agents de lutte biologique dans une stratégie de gestion intégrée des ravageurs du cotonnier en utilisant ces biopesticides.
Author Keywords: Gestion intégrée, Aphis gossypii, prédateurs, pesticide botanique, Coton biologique.
How to Cite this Article
Saturnin Azonkpin, “Effects of Thevetia oil and Top bio on Aphis gossypii and predators in organic cotton production at Gobe in center of Benin,” International Journal of Innovation and Applied Studies, vol. 39, no. 4, pp. 1726–1738, June 2023.
