A light-altering paint boosts food security

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The greenhouse spray coating could lengthen growing seasons in countries like the UK

Spotted: A sustainable agricultural system doesn’t just mean lowering food waste and emissions, it also means ensuring food security for all. Growing more produce while using fewer resources and less land is central to this. Hoping to do just that, researchers at the Universities of Bath and Cambridge have developed a simple spray coating for greenhouses that could boost crop growth and yield in temperate climates such as the UK.

The innovative paint is designed to alter the wavelength of sunlight that shines onto plants. Photosynthesis – where plants create sugars from carbon dioxide and water in the presence of sunlight – is most efficient at the red light wavelength. Sunlight, however, consists of all the wavelengths of the spectrum, meaning that much of it is wasted. By applying the spray to the greenhouse structure, more of the sunlight that penetrates is converted to red light, improving crop yield without needing lots of additional energy-intensive artificial lights.

While the technology, in principle, is nothing new, previous attempts at creating light-altering veneers have used elements such as indium – a rare earth material that is expensive and difficult to recycle. Working with commercial partner Lambda Agri, the Bath and Cambridge team has replaced indium with a patent-pending material that can be sourced at a lower cost and manufactured at scale.

During field trials, the researchers were able to boost the yield of basil grown in treated greenhouses by nine per cent. The coating could help to extend the growing season in countries with less favourable climates, like the UK. That would mean countries wouldn’t need to import fresh produce during off seasons, saving money, cutting transport emissions, and increasing national food security. The researchers also believe the coating may help to improve the taste of fresh fruit by raising the sugar content.

Having submitted a patent for the technology, the team hopes to arrive at a commercially available solution for growers within a few years. Professor Petra Cameron, from the University of Bath’s Institute of Sustainability and Climate Change (ISCC), also told Springwise: “The current push is to incorporate our active ingredient directly into the plastic sheeting that is used on poly tunnels (…) create a fully integrated product, which would then not need to be painted on as it is with greenhouses.”

Written By: Duncan Whitmore