Researchers at Kyushu University have discovered a natural compound found in Manchurian walnut plants that can halt seedling growth. The team, led by Associate Professor Seiichi Sakamoto, isolated the molecule and showed it disrupts early plant development in controlled soil tests.
The finding points to a new kind of bioherbicide that aims to control weeds while reducing synthetic spray use. Unlike other methods that use multiple plant extracts, this approach focuses on one compound, 2Z-decaprenol, which acts as an allelopathic agent.
Previous studies have shown that walnut trees release natural chemicals, known as allelochemicals, that hinder the growth of nearby plants. The main suspect in walnut allelopathy is juglone, but researchers found that Manchurian walnut’s main allelochemical had not been identified before.
In controlled soil tests, the team separated leaf extracts into fractions and tracked their effect on tobacco seedlings. They discovered a single molecule, 2Z-decaprenol, which cut seedling weight and reduced shoot and root length in test system.
The researchers also found that this compound suppresses plant growth by redirecting resources to reinforce its structure. The genetic pattern suggests a double hit: growth slows as the plant spends energy on reinforcement, while key stress management pathways go quiet.
This discovery could be a valuable tool for modern farming, which struggles with weeds that no longer respond to long-used herbicides. A bioherbicide derived from natural sources that works in soil could reduce synthetic spray use and meet tighter market or regulatory demands.
Source: https://www.earth.com/news/plant-walnut-leaf-bioherbicide-compund-discovered-capable-of-killing-weeds-no-chemicals