HORIZONTAL TEMPERATURE DISTRIBUTION IN HEATED GLASSHOUSES: CAUSES AND EFFECTS
Various techniques to measure temperature differences to detect the main causes were tested in large glasshouse blocks. Highest temperature differences were found at high inside-outside temperature gradients but no significant effect of wind direction on the temperature distribution was found. Main causes were imperfections in the heating system and thermal screens and leakage of the glass cover. Economic calculations show that for a tomato crop temperature differences may cause financial losses up to Dfl 2.50 m-2 on a yearly basis.