The effect of time of application and sterilization method of gibberellic acid, and temperature on the seed germination of Erica junonia, an endangered species

Similar stimulatory effects by gibberellic acid on germination of Erica junonia seed are obtained when solutions of this compound are sterilized by filtration or autoclaving at 100°C or 120°C for 15min. Both gibberellic acid and temperature are important factors controlling germination. Incubation at 23/15°C for periods of 1, 2, 3 or 4 weeks prior to stratification at 5,5°C for 12 weeks are equally effective in enhancing germination of 0,5mmol dm–3 gibberellic acid treated seed. Gibberellic acid appears to be more effective when applied during the prechilling incubation period than during the chilling or post-chilling periods. Moderately low constant temperatures (10 – 12°C) are effective in yielding high germination counts of gibberellic acid treated seed. It is postulated that dormancy breaking in Erica junonia seed is controlled by at least two processes with differing temperature coefficients