EUBCE 2026 - Ksenia RADOVSKA - Evaluation of Biologically Active Extractives in Different Morphological Parts of Walnut Trees for Bioherbicide Applications

Evaluation of Biologically Active Extractives in Different Morphological Parts of Walnut Trees for Bioherbicide Applications

Short Introductive summary

While global walnut (Juglans spp.) markets continue to expand due to the fruit’s high nutritional and bioactive profile, this growth generates a proportional increase in agricultural side-streams. To align with circular bioeconomy principles, there is an urgent need to valorize this neglected walnut biomass—not merely as waste, but as a rich feedstock for high-value bio-based chemicals. The walnut tree (Juglans regia) is well-known for its high content of secondary metabolites, particularly polyphenols, flavonoids, and juglone, which exhibit strong allelopathic, antioxidant, and antimicrobial properties [1–5]. In nature, juglone acts as a powerful natural herbicide, inhibiting the growth of competing plant species [6–9]. While the commercial focus remains heavily on the edible nuts, other morphological parts of the tree—such as leaves, green husks, branches, and roots—are rich in extractives but are frequently treated as agricultural waste. This research aims to develop biodegradable, sprayable mulches using these allelochemical-rich extracts for sustainable weed management. Harnessing these by-products offers a natural alternative to synthetic herbicides.

K. Radovska, Latvian State Institute of Wood Chemistry, Riga, LATVIA
M. Pals, Latvian State Institute of Wood Chemistry, Riga, LATVIA
J. Ponomarenko, Latvian State Institute of Wood Chemistry, Riga, LATVIA
M. Lauberts, Latvian State Institute of Wood Chemistry, Riga, LATVIA