Sargassum: Untapped treasure trove for sustainable agriculture

Prof Adesh Ramsubhag, Prof Jayaraj Jayaraman

and Omar Ali, PhD student, UWI

Faculty of Sciences and Technology

Every year, the countries of the Caribbean region, including TT, are plagued by the large amounts of sargassum seaweed deposited on the beaches and coastline areas.

The resulting mass of degrading and critter-infested seaweed is a turnoff for tourists and local visitors to beaches. The overall impact on the tourist sector and national economies in the region is significant.

At the same time, it also poses a major ecological challenge for the coastal environment. Thus the region needs to find suitable strategies to deal with this perennial sargassum problem.

One of the potential strategies that can contribute to solving this problem is to develop industries that utilise sargassum biomass to produce useful and valuable products.

In this regard, researchers from the Department of Life Sciences, Faculty of Science and Technology at UWI have been rigorously working on developing sargassum-based products for use as crop-growth and yield-enhancing agents.

The group has recently formulated a high-end, highly bioavailable, and stable plant biostimulant product using extracts of sargassum biomass. The formulation was extensively tested for its biostimulatory and disease suppression abilities in various crops under greenhouse, hydroponics, and field cultivation systems. Crops evaluated in the experiments included lettuce, various seasonings, tomato, peppers (hot pepper, sweet pepper, pimento) and cowpea.

The findings of the studies showed remarkedly promising results, whereby crops treated with the sargassum formulation had much higher yields and lower incidences of diseases (both fungal and bacterial) than non-treated controls.

The local product was also compared to imported commercial seaweed-based biostimulants that are popular on the market. The results, from both greenhouse and farmers’ field trials, demonstrated that the sargassum product was able to compete effectively and, in some instances, perform better than the imported commercial brands in terms of enhancing yields and quality of produce.

The researchers also assessed the sargassum biostimulant in integrated management systems for reducing the need for synthetic pesticides.

The highest yields were achieved when the product was rotated with generic low-toxicity pesticides. By including the sargassum extract formulation in the management system, it was possible to reduce the fungicide application frequency by more than 50 per cent, without compromising the yield.

One of the concerns that arises with sargassum products is the potential presence of heavy metals such as arsenic, which can be accumulated in the biomass owing to the presence of pollutants in the oceans.

However, the innovative technology used by the researchers resulted in a product that has low levels of heavy metals that were well within permissible levels specified by the water pollution rules of the Environmental Management Authority (EMA) as well as the US Environmental Protection Agency (US-EPA).

Broader-scale field trials are now being done at farmers’ fields and to date, the feedback has been very positive. Farmers have shown very high interest and willingness to use the formulation in their crop production systems. Our main goal now is to develop partnerships with farmers, investors and key stakeholders; to drive this product to the market in the near future for the benefit of TT, and the wider region.

The research by the UWI team was supported by grant funding from the UWI-Research and Development Impact Fund (RDI), and the SARGOOD-FED-INTERREG V-Caraïbes project.

Apart from the sargassum biostimulant formulation product, the team is continually innovating and looking at developing other environmentally-friendly products and cropping systems as part the UWI’s contribution to the sustainable development goals of TT.

UWI ON THE GROUND

A university must be centred in the community, leading on the key issues of the day. Accordingly, UWI, St Augustine, offers this public service series, where its leading scientists and researchers will address climate and disaster challenges – Series 1.

In this offering a research team from the Faculty of Sciences and Technology – Omar Ali, PhD student, UWI, Prof Adesh Ramsubhag and Prof Jayaraj Jayaraman – gives a different perspective on that seemingly annoying substance, sargassum, illustrating its hidden benefits and economic potential.

Prof Rose-Marie Belle Antoine

Principal, UWI, St Augustine