Seaweed-derived bioactives for natural crop protection against herbicide-resistant weeds

Overview

This research explores the use of phenolic and phenolic-like compounds extracted from brown seaweeds as natural bioactives for crop protection. The focus is on combating herbicide-resistant blackgrass (Alopecurus myosuroides), a major weed that significantly reduces crop yields and is increasingly difficult to control with conventional synthetic herbicides. Seaweed-based treatments offer a sustainable, multifaceted solution: they target resistant pests while concurrently improving soil quality and carbon storage. This approach addresses the urgent need to reduce dependence on synthetic chemical inputs in agriculture.

Technical specifications

Key features:

• Water-soluble extracts from brown seaweeds containing phenolic and phenolic-like bioactive compounds
• Dual mechanism of action: inhibition of photosynthesis and disruption of membrane permeability and carbon flow in target plants
• Selective efficacy against herbicide-resistant blackgrass at very low doses
• Validated using germination trials (50 seeds per replicate, n=3) and imaging PAM fluorometry to measure photosynthetic stress (Fv/Fm)
• Significant modification of germination rates in herbicide-resistant treatments compared with non-resistant seeds
• Post-germination stress induction that reduces the competitive ability of weeds against crops

Applications include:

• Natural herbicide development for herbicide-resistant weed management
• Sustainable crop protection solutions for conventional and organic farming systems
• Soil health improvement through seaweed amendment

Technology readiness level

The technology is at an early-to-mid stage of development. Preliminary proof-of-concept data has been generated, demonstrating that brown seaweed extracts are active against herbicide-resistant blackgrass and significantly affect both germination and photophysiology. Future work will optimise extraction protocols, investigate longer-term growth performance post-germination, conduct more detailed photophysiology experiments, and construct a preliminary transcriptome to identify targeted genes. This foundational research is expected to last approximately six months and involves collaboration between Newcastle University and the John Innes Centre. The findings will support further funding applications for extract purification, validation, and potential commercialisation routes.