Efficacy of Wood Vinegars on Insect Control, Agronomic Performance and Yield of Open-field Tomatoes in Côte d'Ivoire

Abstract

Background: In Côte d’Ivoire, tomato production suffers significant yield losses due to insect infestations, which are typically controlled using synthetic pesticides that pose risks to human health and the environment. Wood vinegar, a natural liquid obtained from biomass pyrolysis, contains bioactive compounds with insecticidal and biostimulant properties. This study evaluated the efficacy of locally produced wood vinegars as sustainable alternatives for tomato protection. Methods: The experiment was conducted during the 2024 rainy season in Yamoussoukro, Côte d’Ivoire, on a 250 m² field with slightly acidic soil (pH 6.5), low in nitrogen (0.04%) and rich in phosphorus (37 ppm). Two wood vinegars (WCV1 and WCV2) were applied by spraying at three dilution rates (1:100, 1:200, and 1:300) and compared to a synthetic insecticide (K-optimal 35 EC) and an untreated control. Insect attack rates, agronomic parameters, product efficacy duration, tomato moisture content, and yield were monitored at 18, 32, and 46 days after transplanting. Results: Treatments with wood vinegars significantly reduced insect attacks, with WCV2 (1:100) showing the lowest attack rates (0–16.7%). These treatments also enhanced plant growth parameters, including collar diameter reaching 13.56 ± 1.39 mm with WCV2 (1:200), vegetative growth of 19.83 ± 2.02 cm with WCV2 (1:300), and the largest leaf area of 1453.79 ± 190.09 cm² with WCV2 (1:300). In terms of yield, WCV2 (1:100) produced 19.54 ± 3.65 t/ha, while fruit shelf life increased from 7 to 21–25 days and moisture content decreased from 72% to 55–61%. The activity duration of wood vinegar treatments ranged between 14.33 ± 1.15 and 16.00 ± 0.00 days. Conclusion: Wood vinegars demonstrate strong potential as eco-friendly tools for integrated pest management, improving yield and post-harvest quality while promoting sustainable and environmentally responsible agriculture.