Vacuum drying of seeds - to improve resistance to heat and cold

摘要

The resistance of seeds to heat and cold after primary drying (i.e. natural or conventional artificial drying) is improved by a secondary drying procedure in which the seeds are dried under vacuum (=100 mum Hg) in stages. The 1st stage is effected at 50-60 degrees C for 0.5-24 hrs., after which the temp. is increased by 5-20 degrees C for the next stage. The process is esp. applicable to horticultural seeds, certain small-scale agricultural seeds (e.g. tobacco) and certain commercial seeds with special viability problems. Secondary drying is pref. effected in 4 or 5 stages, with a temp. increase of 10-15 degrees C from one stage to the next. The initial temp. is 50-60 degrees C and the final temp. 90-100 degrees C. Each stage pref. lasts for 1-8 hr. The dried seed is pref. stored in the absence of O2.