Can courgettes be grown in the BEST greenhouse with bubble wrap?

Published on
October 20, 2021

​The BEST greenhouse is a remarkable construction: a semi-curved span with bubble wrap. The greenhouse thus resembles a combination of a tunnel greenhouse and a wide-span greenhouse. Previous research has shown that woody soft fruit can be grown well and energy-efficiently in the BEST greenhouse. The Business Unit Greenhouse Horticulture and Flower Bulbs of Wageningen University & Research started research in the spring of 2021 into the possibilities of the BEST greenhouse for growing courgettes.

The aim of the BEST greenhouse is to save energy and limit CO2 consumption. BEST therefore stands for Bubble Energy Saving Technology. The bubble wrap provides a diffused light. To prevent the temperature from rising too much, the greenhouse is equipped with continuous ridge aeration. In addition, the side walls can largely be opened. The BEST greenhouse is also equipped with a screen, high-pressure atomization, a CO2 dosing installation and heating.

The cultivation of raspberries and blackberries in the BEST greenhouse has been studied in recent years as part of the Kas Als Energiebron programme. The main conclusion of this is that the greenhouse ensures good production with approximately 40% energy savings. Zucchini, like the woody berries, needs a moderate amount of heat and is therefore often grown outdoors. But the yellow courgette in particular is vulnerable to wind and is actually only grown in a covered environment. That is why WUR investigates whether the cultivation of yellow zucchini is also feasible in the BEST greenhouse.

65 fruits per year

A courgette plant in a greenhouse

The research consists of two crops. The first crop was from February to July, and the second started in August. The results of the first cultivation are very positive. For example, 65 fruits per square meter were harvested; the expectation was that 75 fruits per year would be possible. Those 65 fruits are therefore relatively high compared to the production on a practical farm.

In that first cultivation, 5 kilograms of CO2 per square meter was required for cultivation; that is half of the expected 10 kilograms for two crops. The use of natural gas was slightly higher than expected, partly due to a cold period, namely 7.7 m3 gas per square meter (the expectation was 10 m3 in two crops). The second crop is expected to continue into November. Then the final figures will be announced.

This research is funded by the Kas Als Energiebron program.​