MODEL EXPERIMENTS FOR ENERGY SAVING TEMPERATURE CONTROL FOR GERMINATING CUCUMBERS

For a broad temperature range significant improvements were achieved by polynomial regressions of 3^th· to 5^th order calculated for duration of emergence. With linear regression the correlation coefficients were somewhat smaller. The advantage of the linear function is a small number of parameters, which can be explained physiologically estimating the heat sum and the theoretical temperature minimum and maximum of germination.

Using the linear function parameter values of cucumber in different models the seed bed temperature in greenhouses, the amount of fuel and that way the most energy saving temperature control can be calculated.

Duration of emergence and amount of fuel needed for cucumbers decrease with higher set points from November until April. In warmer month the energy demand increases with higher set points.

Recommendations for germinating cucumber are derived on the basis of lowest costs and physiological aspects.