Opkweek en teeltresultaten van kunstmatig belichte tomatenplanten

The effect of artificial illumination during the seedling stage of tomatoes was studied, mainly with plants raised exclusively in artificial light.<br/>The dry weight at the time of planting out and the number of leaves below the first trusses, in this sequence, were the most important criteria for the quality of young tomato plants.<br/><br/>In the illuminated chambers daily production of dry matter increased with brightness from 12.10 3erg cm- 2sec.- 1total radiation up to 24.10 3erg cm- 2sec.- 1from TL 65W 'white' fluorescent lamps and with the length of photoperiod from 16 to 24 h. The increase in daily production of dry matter was associated with a reduction in production of dry matter per unit light energy: as illumination increased, it was used less efficiently, especially if the photoperiod was longer than 16 h per day.<br/><br/>Effects of light and temperature on the leaf number were examined. Results of various cropping experiments demonstrated the importance of illumination during the raising period.<br/><br/>The physiological and practical consequences of the results were discussed