By Orville C. Baldos, Joseph DeFrank and Scott B. Lukas
The control of both seed storage temperature and humidity is essential for optimizing dry after-ripening of seeds. Manipulating these factors to process small seed batches often require expensive equipment such as incubators and desiccators. To reduce cost, we have devised a portable after-ripening system made from readily accessible components, such as a 5-gallon (18.93 L) plastic bucket (with a screw top lid), bubble wrap insulation, silica gel-based desiccator and a seed germination heat mat (connected to a thermostat). To assess the storage conditions of the DIY (do-it-yourself) after-ripening system, dried seeds and awns of piligrass (Heteropogon contortus) were placed inside the bucket and stored for 12 months at the 30°C setting of the seed germination heat mat. Temperature and relative humidity during the storage period was monitored using a datalogger (Onset HOBO® UH100). Records obtained from the datalogger indicate that the bucket can maintain an average temperature of 30.92°C (standard deviation = 0.96°C) and an average humidity of 30.81% (standard deviation = 1.89%). A previous study on after-ripening of piligrass indicates that this storage condition falls under the ideal range of storage temperature (30°C) and storage humidities (12% to 50% eRH). Results of the first year of evaluation suggest that the DIY bucket can be used for small-scale after-ripening of piligrass seeds. The potential exists for the modification of the desiccant type and temperature settings to facilitate after-ripening in a greater range of species.
This recorded talk was originally presented as a poster at the National Native Seed Conference, February 13-16, 2017 at the Omni Shoreham Hotel, Washington, D.C.
Here's the link to download the poster: https://docs.google.com/a/hawaii.edu/...
The method described in this webinar was effective on tropical species, but might not be suitable for species from a different environment, without adjusting tempeature and humidity parameters.