"Tomato crop has been generative from the beginning"

In November last year, Dutch tomato grower Jan Verkade installed a brand new lighting system at his greenhouse in 's-Gravenzande. The grower, for whom lighting is new, consciously opted for this technique to move production to another season and thus achieve a higher return. A hybrid installation with Philips GreenPower LED interlighting was chosen.

The tomato grower had lighting installed on 2.7 ha by Stolze. A combination was chosen of LED interlighting modules with HPS (High Pressure Sodium). In addition 135 µmol/m2/s Hortilux 1000 watt lamps were installed and 55 µmol/m2/s Philips GreenPower LED interlighting, together 190 µmol/ m2/s. In total 6610 modules were installed. Fred Schape, in charge of the daily management at Verkade, is very enthusiastic about the crop condition and looks forward to what the new installation will bring him.

Verkade has two companies in 's-Gravenzande of 4.7 hectares in total, which until recently were not lit. The company was faced with the choice to expand or to increase production. They chose the latter. Schape: "The production of lit tomatoes is at a time of year that the prices are better. In addition, production goes up."

The tomato grower had to choose between only HPS lamps or a hybrid system. He visited companies with hybrid installations such as Jami BV in Bergschenhoek and Kwekerij Wim Peters in Someren and was impressed with their results. Nevertheless it was a big step to switch from unlit tomatoes to cultivation with hybrid lighting. Schape: "We saw the advantages of the combination of toplighting and interlighting because it gives us more possibilities of steering the crop."

The company specializes in coarse TOVs. This year it's growing the Merlice variety, which was planted in week 44. In the initial phase the number of heads of the grafted, topped plants was 2.3 per m2. In week 46 a head was added. The last head was added in week 48, bringing the final result to 3.8 stems per m2.

Schape is satisfied with the state of the crop: “I’m really pleased. The crop has been generative from the beginning and I notice that the plant sends its energy to the fruit very easily."

For Philips, this is the first 'Westland' LED project with a tomato grower. LEDs came into the picture because Verkade’s greenhouse has a limited height of 4.85 meters. This means that it is not wise to hang the full capacity of HPS lamps above the crop because of the radiant heat. LEDs emit considerably less radiant heat and are therefore more suitable.

The modules between the crop can move with the growth of the plants. This way the light gets much deeper into the crop and plants are optimally exposed along their entire length. With LEDs it is also possible to provide grow light longer than is usual with HPS lamps.

For the inhabitants of 's-Gravenzande it was soon clear that Verkade was experimenting with its new lighting installation. During the first test there was already a lot of tweeting about the light colors appearing over the company.

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