Control of sweetpotato weevil (Cylas puncticollis Boh) through cuttings disinfection using seed oils from neem (Azadirachta indica (A. Juss)) and Carapa procera (de Candolle)

In Burkina Faso, the weevil (Cylas puncticollis Boh) causes significant damage to sweetpotato in the field, especially when cuttings used originate from infested fields. In order to break the chain of infestation, cutting disinfection before transplanting is usually recommended. This study aims to evaluate the efficacy of seed oil from Azadirachta indica and Carapa procera in disinfecting sweetpotato cuttings against C. puncticollis eggs. The initial concentrations of oils are 100 g of oil per 100 ml of water. After pre-testing, concentrations of 16, 14, 12, 8, and 4% for the oils were used. Disinfection was carried out by soaking the cuttings in each of these solutions for 2 h, 1 h, 30 min, 15 min, and 5 min. Control cuttings were soaked in distilled water for 30 min. The results show that the rate of egg hatching in sweetpotato cuttings soaked in oil solutions varies from 0 to 39% for neem oil and from 26 to 35% for C. procera oil. The hatching rate was 100% for cuttings soaked in the control solution. Pending quantification of the level of active ingredient in the different concentrations, it is recommended that the 12% neem oil solution be used. Key words: Sweet potato pest, biopesticide, seed, Burkina Faso, control method.