Telen met gestuurde vochtafvoer : komkommers in de Venlow Energy kas

Funded by Kas als Energiebron, Wageningen UR Greenhouse Horticulture conducted an experiment witth cucumber in the Venlow Energy greenhouse with a high-wire system. The objective was to achieve a minimal evaporation during cultivation under double glazing and a film screen. In the night the evaporation fell to 15-25 g. m-2.hour-1. This was enough to grow cucumbers without deficiency symptoms. Only in March, some degree of “bolblad” occurred, but after a few sunny days the crop well recovered. The film screen was kept closed until 2 hours after sunset and one hour before sundown closed. This provided no problems for cultivation. In the night the humidity could rise above 95% without Mycosphearella problems. For the new cultivation strategy this means if other factors such as horizontal uniformity of the climate are good that cultivation in high humidity and with minimal ventilation is possible. For the Venlow Energy greenhouse ventilation rate was 0.37 and this delivers in winter conditions a sufficient degree of natural ventilation and moisture management.