The 2009 ASHS Annual Conference

Fruits of bog blueberry, Vaccinium uliginosum, were collected in August and refrigerated for 8 days after which half were cleaned to remove seeds and the remainder were frozen (-5C). Four replicates of 50 fresh seeds were sown onto filter paper in Petri dishes as a control. Extracted seeds from fresh berries were air dried and sown as before at 2-3-day intervals up to two months to learn the effects of drying on seed germination. This experiment was repeated with seeds from frozen berries to learn the effects of freezing on seed germination. Seeds air dried at 21C for 60 days were cold stratified on moist filter paper at 4C for 30, 60, 90 and 120 days and compared to dry seeds held at 4C and seeds extracted from frozen berries. Air-dried seeds showed a linear decline in percent germination with the length of the drying period, but all percentages did not exceed 35% during the 60-day period. Seeds from frozen berries maintained high germination percentages regardless of length of freezing time (70 <u>+</u> 12%). Cold stratification improved germination (28.5 – 36.0%) over air-dried seeds (9.5<u>+</u>1.9%), but there was no difference among stratification times. Germination of all stratified seeds was significantly lower than seed extracted from frozen berries (71.0<u>+</u>10%). Optimum germination occurs with seeds extracted from frozen berries and sown immediately and not permitted to dry out.
    Softwood stem cuttings of wild-harvested bog blueberry from new growth rooted more than 50% from 20 June through August, and rooting did not differ among collection dates (greenhouse mist propagation, 25C bottom heat, 0.3% IBA powder, perlite/ vermiculite 1:1 (v:v)). Cuttings collected from 30 different wild locations showed a significant location effect in rooting percentages. Among individual plants, rooting ranged from 0% to 100%, averaging 51<u>+</u> 24%. Optimum cutting collection time is nearly all summer, and both plant variation and location influence final rooting success.