This work was carried out to evaluate drying procedures of primed onion seeds. Samples of four seed lots (cultivar Petroline) were primed between two moistened sheets of germination paper towel, at 15ºC, during 48 h, and then submitted to the following drying processes: fast drying (in oven with air circulation, under 35-40ºC, during approximately 24 h); slow drying (seeds kept in a chamber under 20ºC and 50-60% relative humidity during 72 h); incubation in PEG 8000 solution (340 g/L water), under 8ºC, during 24; 72 and 120 h; incubation in a water bath under 40ºC, during 1; 3 and 5 h; and incubation in a chamber under 35ºC, during 24 and 48 h. After the slow drying and the incubation processes, seeds were submitted to fast drying to complete seed desiccation to obtain the moisture content around 6-8% (fresh weight basis). The physiological potential was evaluated through germination, speed of germination, accelerated aging and electrical conductivity tests. The experiment was carried out in a completely randomized design, with 12 treatments and four replicates for each test. Results showed that the incubation in PEG 8000 solution drastically reduced seed germination and vigor of primed seeds. In addition, there were no wide differences among the process of fast drying, slow drying, incubation in water bath and incubation under 35ºC. The fast drying was considered the best procedure to reduce moisture content of primed onion seeds, with the advantage of being faster (the period required was about 24 h) and more practical.
Allium cepa; priming; incubation; germination; vigor
