Nighttime temperature

Nighttime temperatures have a huge impact on growth rate, nutrient uptake, and fruit set. Prolonged cold spells limit, among other things, phosphorus uptake, while very high nighttime temperatures increase plant respiration and can reduce crop quality. For most varieties, the optimal nighttime temperature is around 16–20°C. In a tunnel, it’s a good idea to use a thermometer that records the minimum temperature and to close or open the covers well in advance, avoiding both overcooling and overheating.