TEMPERATURE AND SEED MOISTURE GOVERN GERMINATION AND STORAGE OF GERBERA SEED

Temperature, relative humidity (RH), desiccation, and hydration affect gerbera (Gerbera jamesonii H Bolus ex Hook.f) seed storage and germin ation. Germination percentages (G) were maximal and about equal at con stant 15, 20, or 25C in darkness or light but lower at alternating tem peratures having the same mean temperature. The number of days to 50% final germination (T-50) and between 10% and 90% germination (T-90 - T -10) required the fewest days at constant 25 or 30C; longer germinatio n periods resulted with alternating temperatures. Reducing seed moistu re from 7.1% to 3.5% had no effect on G, T-50, or T-90 - T-10 values, but at seed moisture levels <3.5%, G was lower and T-50 and T-90 - T-1 0 longer. Germination percentages were similar after seed storage from 5 to -5C, but G was lower after storage at -10C or lower. Low-tempera ture seed storage had no effect on T-50 or T-90 - T-10 values. Seeds h ad highest G and lowest T-50 and T-90 - T-10 values when germinated at 52% seed moisture, with large declines and delays in germination at l ower and higher moisture levels. Seed storage for 12 months without re duction in germination was possible at 5C and 11% or 32% RH. Seeds sto red at 52% RH lost G at all temperatures, and no seed germinated after storage at 75% RH and 15 or 25C. Seed stored at 5 or 15C and 11% to 3 2% RH had the fewest days to T-50 and T-90 - T-10.