Climate change is increasingly challenging agricultural productivity. Rising temperatures and prolonged heatwaves disrupt plant development, particularly during the reproductive phase, when pollen viability, fertilisation, and early fruit formation determine final yield. Supporting crops through these sensitive stages is essential to maintaining food production in a warming climate.
A newly published study investigates the effectiveness of two seaweed-derived biostimulants in mitigating high-temperature stress in chilli pepper plants. The research evaluated extracts derived from Ascophyllum nodosum (Martello®) and Ecklonia maxima (EME), both of which are marketed for improving plant stress tolerance.
Study Overview
Plants were exposed to elevated temperatures of 36/18°C for fifteen days during their reproductive phase. Researchers assessed physiological, biochemical, and anatomical responses linked to reproductive success, stress mitigation, and yield formation.
Key Results
The study demonstrated that Martello® delivered clear and measurable benefits under heat stress:
- Enhanced Reproductive Performance
Martello® improved pollen viability by 94% and increased the number of developed ovules in pistils by 48% compared with untreated heat-stressed plants. These improvements directly support successful fertilisation and fruit set. - Reduction of Oxidative Stress
Treated plants showed significantly lower oxidative damage in leaves, alongside sustained expression of heat-response genes HSFA2 and HSP101, indicating improved cellular protection mechanisms. - Maintenance of Photosynthetic Function
Leaf fructose levels increased by 48%, suggesting better preservation of photosynthetic activity during stress conditions. - Improved Plant Structure and Resource Transport
Martello® increased xylem vessel elements by 35% and ray parenchyma by 60%, enhancing water transport capacity and starch storage—critical adaptations under thermal stress. - Yield Impact
These combined physiological and structural improvements resulted in a 50% increase in yield in plants treated with Martello® under high temperatures. In contrast, the Ecklonia maxima extract (EME) showed no measurable yield benefit under the same conditions.
What This Means for Climate-Resilient Agriculture
The findings provide strong scientific evidence that carefully designed biostimulants can:
- Support plant reproductive success under extreme temperatures
- Improve thermoadaptation and physiological resilience
- Maintain productivity in challenging environmental conditions
- Offer a sustainable tool for growers facing increasing climate variability
As global agriculture continues to adapt to warming climates, solutions that enhance natural plant defence and recovery mechanisms will be essential. This research highlights the important role that marine-derived biostimulants can play in safeguarding crop performance and ensuring yield stability.
Read the Full Paper on Open Access:
Full article available at:
https://doi.org/10.1016/j.stress.2026.101291
