SEEDLING EMERGENCE AND GROWTH OF SOLID-MATRIX PRIMED KENTUCKY BLUEGRASS SEED

Seed priming is effective in reducing the time required for germinatio n and emergence, and for increasing final germination and/or emergence especially under sub-optimal conditions. This study was conducted to determine whether advanced emergence due to solid matrix priming (SMP) is followed by advanced seedling growth of Kentucky bluegrass (KBG) ( Pea pratensis L.) under sub-optimal conditions (15/5 degrees C). Coleo ptile, the second and third leaf emergence, and seedling size 28 d aft er emergence were examined in four cultivars, which differed in their seed sizes. Distributions of coleoptile emergence over time were signi ficantly affected by SMP, and seedlings from SMP seed emerged more rap idly and uniformly in three cultivars. Moreover, the number of days re quired for 50% emergence (T-50) was shortened by 5 to 14 d. In contras t, the rate of second and third leaf emergence and seedling size 28 d after emergence did not differ between seedlings emerged from unprimed and SMP seed, indicating that the vegetative growth is basically dete rmined genetically. However, SMP could subsequently enhance the mean s eedling size of a population by increasing the number of seedlings tha t emerged rapidly. The SMP treatments could provide practical benefits on stand establishment of KEG under sub-optimal temperatures by enhan cing the mean seeding size but not by increasing the growth rate of in dividual seedlings.