A GROWTH MODEL TO PREDICT YIELD AND ECONOMICAL FIGURES OF THE CUCUMBER CROP

The demand for models which allow the calculation of optimized temperature control increases with rising energy prices.
For this purpose the prediction of yield and output depending on the set points for the heating system and the determination of the energy quantities needed are necessary.
From both figures the term output minus energy cost is derived to assess the relative superiority of different temperature set points.

Prediction of crop growth as a function of temperature set point can be done sufficiently with a multiple regression analysis if definitely limited growth phases are used as duration from planting to 1,0 kg of fruits picked.
Further yield accumulation doesn’t represent such a limited growth part.
Therefore prediction of yield per week by multiple regression analysis was done with values derived from yield time functions (MITSCHERLICH function). Independ variables are: temperature, radiation, plant age and the season.

Within the temperature range tested the highest return resulted from the lowest set point for the heating system.
More research work is needed to investigate the temperature limits and more details of temperature reaction.

Working-party on Greenhouse Cucumber

H.-P. Liebig

https://doi.org/10.17660/ActaHortic.1981.118.16