Preventing cold stress in greenhouses Scientists have made advances in support of a system for monitoring cold stress in greenhouse crops. Climate Change and Environment © Cecilia Stanghellini Low night-time temperatures in greenhouses have been linked to losses in crop yield. This is either addressed through heating with fossil fuels or the greenhouse remains unheated and crop productivity suffers. The EU-funded 'Early detection of low temperature plant stress: Towards a tool for energy-efficient production' (EARLYTOOL) project set out to improve our understanding of how plants react to cold stress. In addition, the project wanted to test a proof-of-concept cold-stress indicator. Researchers began by exposing red pepper seedlings to low night temperatures in a laboratory environment. They measured several parameters of plant health and growth rate to feed into a model of cold stress in plants. The study revealed a decrease in water movement after exposure to cold temperatures, as well decreased sugar metabolism. This in turn led to decreased leaf area and retarded growth. EARLYTOOL then tested two commercially available, non-invasive plant monitoring tools: CropReporter and PlantEye. Both sensors were able to detect cold stress in plants within a few hours of cold onset. Project scientists concluded that low night-time temperatures do impact on crop productivity in greenhouse plants. Their proposed monitoring method, combined with night-time heating, would reduce energy costs and improve productivity significantly. Keywords Cold stress, greenhouse, crop growth, low night temperature plant stress, energy-efficient production, plant health, sugar metabolism, leaf area, plant monitoring, night-time heating
