Treatments toOvercome Seed Dormancy
Softening seed coats and othercoverings (Scarification)
MechanicalScarification
Sandpaper, hammer, knife, tumbler.
Hot WaterScarification
Dropinto hot water (77 to 100oC), remove from heat, allow to cool and soak for 24 hours.
Acid Scarification
Seeds,in small batches, are brought into contact with 93% Technical Grade sulphuric acid. Atthe end of a set period of time (from as little as a minute to as much as anhour and a half), seeds are rinsed and acid is neutralized with bakingsoda. Initially shiny seed coats wouldappear dull after this treatment.
Warm MoistScarification
Keepplants in warm moist soil or unsterilized sand forseveral months to soften seed coats through microbial activity. Seeds may also be planted directly in the summeror fall while soil temperatures are warm.
Stratification
RefrigeratedStratification
Stratificationis accomplished by placing seeds in moist planting medium in a cold environmentfor a period of time (two weeks to three months). Seeds require moisture, cold and oxygen. In general, this period of time allows anundeveloped embryo to mature.
Outdoor Stratification
Seedsmay be kept outdoors through the winter in lined pits or raised beds. They must be protected from freezing, dryingand rodent predation (use wire netting in the soil). Pits or beds are layered with clean sand,medium with seeds, more clean sand, etc.
Outdoor Planting
Somecategories of seeds may simply be planted outdoors in the fall and naturalstratification is allowed to happen.
Leaching
Inhibitors in seedcoat
Leachingsimply requires washing seeds with fresh water.It may be accomplished by running water over seeds in a container (mason jar) for 12 to 48 hours. For longer washing, and for seeds thatproduce a large amount of soluble substances, water should be changed every 12hours, or seeds should be washed in running water. If you use running water or a bubbler, foammay be produced; either use cheesecloth to prevent seeds from being carried outof the jar, or sit the jar in a pan.
Inhibitors in pulp
Somechemical inhibitors are found in the pulp of fleshy fruit. Pulp should be removed by soaking ormaceration; seeds should then be washed.
Laboratory Treatments
Prechilling
Storeimbibed seeds at 5 to 10oC for five to seven days before attemptinggermination.
Predrying
Subjectdried seeds to 37 to 40oC for five to seven days prior togermination.
AlternatingTemperatures
Usedaily alternation of temperatures , going from 15-20oCto 30oC, with seeds held out the lower temperature for 16 hours andthe higher temperature for 8 hours.
Light Exposure
Lightshould be provided by cool-white fluorescent lamps, at high intensity, for atleast eight hours daily. Seeds should beimbibed and placed on tip of the medium.
Potassium Nitrate
Moistensubstratum with 0.1 to 0.2 percent potassium nitrate solution.
Hormones
Soakin gibberellic acid or cytokinin(kinetin) solution. Twelve to 24 hoursoak is recommended. Concentrationsvary.
