Scientists have developed a spray coating that increases crop productivity and saves energy in greenhouses.

Due to the climate and geographical latitude, the growing season in the UK is relatively short, requiring the import of most fruits and vegetables from Europe. Farmers grow crops in greenhouses with artificial lighting, consuming a large amount of electricity. In response to this, scientists from Bath and Cambridge universities, together with Lambda Agri, have developed a spray coating for greenhouse glass. It will increase the productivity of farmers while consuming less energy, according to a press release from the University of Bath. This research has been published in the journal Advanced Materials Technologies.

Photosynthesis is the process by which plants use sunlight to convert carbon dioxide and water into sugars. This process is most efficient with red light wavelengths, while green light is least efficiently absorbed by plants and is reflected, making plants green.

Sunlight consists of the entire spectrum of colors, and a large part of the light falling on plants is not utilized by them.

The new spray coating applied to greenhouse glass, similar to a lacquer, absorbs blue light and converts it into red light. This increases the availability of red light to plants, resulting in increased crop yields.

Prior to this, American researchers had achieved increased plant growth using similar technologies, but they used rare earth materials such as indium. These materials are expensive and environmentally unfriendly to produce. In this project, Bath and Cambridge scientists replaced indium with a cheaper and more accessible material for which a patent application has already been filed. Additionally, they proposed using a chemical flow reactor for coating production, which speeds up the process and makes it more scalable.

Professor Petra Cameron from the Institute for Sustainable Development and Climate Change at the University of Bath noted: "Our coating works similar to ultraviolet light in a nightclub, which makes a gin and tonic glow. We use molecules that absorb ultraviolet light and emit it in the red spectrum. As a result, photosynthesis becomes more efficient, allowing for higher crop yields with less light. In field trials, we observed a 9% increase in basil yield when grown in treated greenhouses. This means that in the future, our technology could be used to extend the growing season and reduce the use of artificial light, saving money and reducing carbon emissions. The coating also diffuses light, further increasing crop yields. There is even evidence that it enhances the taste of fruits by increasing their sugar content."

Professor Dominic Wright from the Department of Inorganic Chemistry and Materials Science at the University of Cambridge said: "This is a great example of how fundamental science can be applied to real-world problems. This is particularly important considering food security and global warming. There is a real possibility that our technology will have a significant impact on the cost and availability of fresh fruits and vegetables, especially in Northern European countries like the UK, where weather conditions are far from ideal."

Dr. Monica Saavedra from Lambda Agri stated: "Lambda Agri is committed to fighting food poverty using sustainable methods. Both universities - Cambridge and Bath - share our vision and collaborate with us in achieving this goal."

The team has applied for a patent for their technology and hopes to make it commercially available to farmers in a few years.