|
|
COLLECTION - STORAGE - PRETREATMENT - STRATIFICATION - SOWING - INDEX |
Seed from native trees and shrubs have an in built dormancy mechanism. This aids the survival of wild plant populations by preventing out of season germination and by spreading eventual germination over many weeks or years. Dormancy is the result of a combination of several properties held by the seed including physical, chemical and physiological. OVERCOMING DORMANCY To get good germination rates the seed has to be subjected to a pre-treatment regime to remove the dormancy prior to sowing. The treatment is divided into two phases. 1. Warm treatment at 20-25 C e.g. an airing cupboard. 2. Cold treatment at 1-5 C e.g. in a fridge [not the freezer as the excessively low temperatures would kill the seeds]. PROCEDURE For all seeds requiring pre-treatment there is a standard procedure to follow this is detailed below 1. Soak seeds for 48 hours at 3-5 C. 2.Drain seeds. 3. Put seeds and compost if required into plastic container e.g. a margarine tub. 4. Place at pretreatment temperatures for the required time. [ see attached page A ] 5. Once a week open container, mix the seeds and re-moisten if the compost is drying out. 6. At the end of pretreatment remove the compost and dry the seeds in a cool, well ventilated, shaded place. Any chatted seed must not be dried at all. SOWING DATES The pretreatment regime must be completed in time to allow sowing to be done between mid-March and the end of April. Care must be taken to avoid the drying out of seedlings or inducing secondary dormancy by sowing to late in the season.
|