• antifungal activity
• chitosan
• microcapsules
• micronized biochar
• wood distillate

Wood distillate (WD), is a liquid byproduct of charcoal production. It has antimicrobial and antifungal properties thanks to its combination of over 300 components, including organic acids, polyphenols, and tannins. Chitosan (CH) is a biopolymer with antioxidant properties that can improve plant defence mechanisms, while biochar (BC) is a carbon-rich material that can improve the bioavailability of soil nutrients and crop productivity. The aim of this work was to develop WD-containing microcapsules coated with CH or CH+micronized BC, and finally test their effects against the soil-borne fungal pathogen Macrophomina phaseolina.
Microencapsulation of WD was performed by ion exchange gelation method, using sodium alginate as the polymer. The microcapsules were coated with a CH solution or a CH + micronized BC suspension. Three types of microcapsules were produced: uncoated, CH-coated, or CH-BC-coated WD microcapsules. In vitro experiments were conducted to observe their solubilization through pH measurements, while their effects were evaluated on the in vitro growth of M. phaseolina.
The microencapsulation of the WD and the formation of the microcapsule coating were successfully performed. WD microcapsules coated with CH and micronized BC, provided a significant reduction in the in vitro growth of M. phaseolina. Further investigations on the effects of these microcapsules against soil-borne pathogens could be conducted in light of their potential use in sustainable agriculture.