Getting the light right for growing tomatoes was a major challenge for Melrose. However, with the cost of electricity ever increasing, it was also important for the light system to provide maximum return for every KW of energy used. To address this issue, Melrose Salads collaborated with Philips to trial LED grow lights at the Flavourfresh Salads nursery in Lancashire.
The hybrid system, comprising of LED interlights and toplights, was tested on a small cherry tomato batch. The system consists of Philips GreenPower LED interlighting modules in two rows (delivering 110 μmol/m2/s) and Philips GreenPower LED toplighting modules (delivering 112 μmol/m2/s).
The trial results were promising. After two days, the plants already looked stronger, with darker leaves, more purple anthocyanin in the head, and a stronger truss. Because the light recipes can be tailored to meet the needs of each different crop, Melrose Salads will be able to get similar results across its whole product range.
The hybrid LED top/interlighting system makes it possible for growers with low-ceilinged greenhouses to keep the lighting on during winter. Without the negative effect of heat radiation, the greenhouse retains more C02, which will lead to higher production.