Abstract
Grafted tomato (scion: Lycopersicon esculentum Mill. cv. Momotaro; rootstock: cv. Helper M) plug seedlings were stored at 10°C for different durations (7, 14 or 21 d) under the optimum combination of CO2 concentration and photosynthetic photon flux density (PPFD) determined in a previous study (0.25% CO2 and 1.9 μmol m-2 s-1 PPFD continuous red light from light emitting diodes) . The stored seedlings were transplanted and cultivated at 25°C and 200 μmol m-2 s-1 PPFD during the 16 h light period and at 20°C during the 8 h dark period for 28 d. The maximum storage duration was determined using strict criteria based on visual quality scores, aerial- and subterranean-part dry weights during storage, stem length, stem diameter, leaf number, aerial- and subterranean-part dry weights, required days to produce the first flower truss, first flower truss setting node and flower-bud number of the first flower truss during cultivation following storage. The results indicate that the maximum storage duration of grafted tomato plug seedlings stored at 10°C under the optimum combination of 0.25% CO2 and 1.9 μmol m-2 s-1 PPFD was 21 d, and that the duration was at least three times longer than the duration for the seedlings stored at 10°C under conventional dark storage conditions.
