Sorghum (Sorghum bicolor L. Moench) seeds were primed in various concentrations of polyethylene glycol (PEG), NaCl, KNO3, glycerol or boric acid for 1, 2 or 3 d at 25 degrees C. Following priming, germination tests were carried out in darkness at 14 degrees C in darkness. All priming treatments significantly improved germination performances (germination percentage, germination rate and spread of germination) of sorghum at 14 degrees C. The highest final germination percentage (FGP) was obtained from the seeds primed in 300 g.L-1 PEG for 2 d (73.0%) while nonprimed control seeds had FGP of 54.50%. Seeds were also primed in 300 PEG g.L-1 supplemented with various concentrations of methyl jasmonate, 1-aminocyclopropame-1-carboxylic acid, benzyl adenine (BA), acetyl salicylic acid, gibberellic acid or double combinations of related plant hormones. Inclusion of 50 mu M BA into priming media further enhanced FGP (89%). The results obtained suggested that priming of sorghum seeds in 300 g.L-1 PEG for 2 d at 25 degrees C could be used to enhance sorghum germination at low temperature, while the inclusion of plant hormones per se into priming media could be more effective than double hormone combinations.