The effects of incorporating plant growth regulators into the priming solution on low temperature germination and emergence performance of muskmelon [Cucumis melo L. (Reticulatus Group) cv. 'Athena'] seeds were investigated. Seeds were primed for 6 days at 25 degrees C in darkness in 3.5 % (0.35 M) KNO3 solution containing one of the following: 1, 3, 5 or 10 mu M methyl jasmonate (MeJA), or 1, 3, 5 or 10 mM spermine. Following priming, seeds were subjected to germination and emergence tests at 15 +/- 0.5 degrees C. Priming muskmelon seeds in the presence or absence of plant growth regulators significantly improved germination percentage, rate and synchrony at 15 degrees C compared to untreated seeds. Inclusion of both MeJA and spermine at all concentrations except 10 mu M MeJA resulted in higher germination percentages compared to seeds primed in KNO3 only. The highest germination percentages were obtained from seeds that were primed in KNO3 solution supplemented with 1 mu M MeJA (96 %) and 1 mM (94 %) spermine. Moreover, the presence of both growth regulators in the priming solution improved low temperature emergence of muskmelon seeds compared to untreated seeds and seeds primed in KNO3 solution alone. Inclusion of 1 mu M MeJA and 3 mM spermine into the priming solution led to the highest emergence percentages with 90 % and 85 %, respectively, while priming in KNO3 solution in the absence of plant growth regulators resulted in significantly lower emergence percentage (31 %). Therefore, priming in 1 mu M of MeJA or 3 mM spermine incorporated into the KNO3 solution can be used as an effective method to improve low temperature performance of muskmelon seeds.