Sweet Chestnut Wood Distillate’s Role in Reducing Helicoverpa armigera Damage and Enhancing Chickpea Performance: Evidence from Field Trial

The moth Helicoverpa armigera (Lepidoptera: Noctuidae), better known as the pod borer, poses significant threats to chickpea (Cicer arietinum L.) production. Therefore, effective and sustainable crop management strategies are required to mitigate the impact of this cosmopolitan pest. The present study aimed at investigating the potential of wood distillate (WD), a liquid byproduct of the pyrolysis of waste lignocellulosic biomass, to both reduce H. armigera pest incidence and to enhance crop yields in field-grown chickpea. The application of WD as a foliar spray effectively reduced the number of damaged pods by 35% during the plant´s reproductive stage compared with water-sprayed plants (~16 vs. 24 bored pods plant−1, respectively) and increased the number of healthy pods (~16 vs. 10 pods plant−1, respectively). Moreover, the lower pest incidence was accompanied by an improvement of both the seed yield and the quality at the plant´s full maturity stage. Specifically, WD-treated plants increased both the number and weight of seeds by ~80% compared to water-sprayed plants (~23 vs. 13 and 5.5 vs. 3 plant−1, respectively) which further showed a remarkable improvement in their nutritional value, with the concentration of total polyphenols, flavonoids, starch, calcium, and magnesium increasing by 17%, 56%, 43%, 23%, and 15%, respectively. These results underscore the potential of WD to both improve chickpea performance and to reduce H. armigera damage to sustainably improve the productivity of this critical legume crop, aligning with the principles of the circular economy and offering an environmentally friendly alternative to synthetic pesticides and fertilizers in agriculture.