Seed treatments to advance greenhouse establishment of beet and chard microgreens

Seed treatments to advance the establishment of table beet or chard (Beta vulgaris L.) for greenhouse microgreen production were examined. While germination percentage was little affected, appreciable germination advancement in both crops was achieved using all seed treatments of matric priming (-1 MPa at 12degreesC for 6 d in fine vermiculite) or various soaks (water, 20degreesC for 48 h; hydrogen peroxide, 0.3% at 20degreesC for 48 h; hydrogen chloride, 0.3 M at 20degreesC for 2 h; or sodium hypochlorite, 4% at 20degreesC for 3 h). The most pronounced seedling emergence advancement, however, was gained by germinating seeds in fine grade vermiculite and sowing the germinated seed plus vermiculite mixture. No additional advancement in seedling emergence or growth was achieved by priming or soaking the seeds in hydrogen peroxide before germinating the seeds in the vermiculite. Germinating the seeds in shallow (c 4 cm deep) vermiculite (150% initial water, c 1 seed :3 vermiculite dry weight ratio, 27degreesC) for 2 d (table beet) or 3 d (chard) resulted in 0.33-fold and 2.79-fold greater shoot fresh weight, respectively, at 11 d after planting than was achieved by sowing untreated seeds.