P. A. Brocklehurst

Effects of osmotic priming on seed germination and seedling growth in leek

Abstract Priming four seed-lots of leek ( Allium porrum L.) cultivar ‘Winterreuzen’ in PEG solution significantly improved the rate and uniformity of seed germination, particularly in the slower-germinating lots. In both field and glasshouse conditions, priming improved the rate and generally improved the uniformity of seedling emergence. Earlier emergence after priming gave rise to higher mean plant weights 10 weeks after sowing. There was no effect of priming on seedling relative growth rate under controlled conditions. Drying-back the primed seeds slightly delayed germination and emergence (compared with seeds which had been primed but not dried-back) because of the time taken for the seeds to re-imbibe water. Most of the beneficial effect of priming was retained after drying-back.

Priming and pre-germination of parsnip (Pastinaca sativa L.) seed

SummarySeedling emergence and growth responses to priming seeds in polyethylene glycol solutions, to germinating them before sowing and to a combined priming and pre-germination treatment were examined in the field and growth rooms using several stocks of seed. Priming or priming and pre-germinating seeds of a slowly germinating stock improved the percentage seedling emergence compared with untreated and pre-germinated seeds. In rapidly germinating stocks all three seed treatments showed similar levels of emergence which were higher than those of untreated seeds. Both priming and pre-germinating seeds reduced the mean emergence time and, in general, the effect of the combined treatment was greater than either treatment alone. Priming alone generally had no effect on the spread of emergence time or on seedling or plant weight variability, but pre-germinating seeds increased variability, particularly in a slowly germinating stock. Priming seeds before pre-germinating them reduced this variability.