BULK PRIMING AND DRYING OF LEEK SEEDS - THE EFFECTS OF 2 POLYMERS OF POLYETHYLENE-GLYCOL AND FLUIDIZED-BED DRYING

The effects of priming with different PEG solutions on the germination and emergence characteristics and the early plant growth of leek seeds (Allium porrum L.) cv. Winterreuzen were investigated. Priming for 7 days with -1.0 MPa solution (both PEG 600 and PEG 6000) gave results as good as priming for 14 days with -1.5 MPa PEG 6000 solution. Priming in bubble columns was as effective as priming on filter paper. Drying back after priming reduced the benefits derived from priming, spread of germination/emergence time being affected more drastically than the mean germination/emergence time. Individual plant weights from primed seeds showed clear improvement over untreated controls. The benefits of priming are clearly seen in tests performed under controlled environmental conditions (ISTA and glasshouse tests) similar to those used commercially for producing transplants. Fluidised bed drying of primed seeds showed promise, but further work is needed to define optimum conditions.