Effects of ethylene, gibberellins, kinetin, nitrate, light, and temperature, each alone or combined with other factors, were studied on the germination of dormant seed of field pennycress (Thlaspi arvense L. # THLAR). Treated seed were incubated at a range of constant temperatures, at temperatures alternating daily between 12 and 22 C (12 h each), or at 12 C followed by transfer to 22 C. No germination ocurrred in water under any conditions. When applied in the dark KNO3 had no effect on germination under any of the temperature regimes. A combination of KNO3, light, and a shift in temperature from 12 to 22 C induced 100% germination. Four days of incubation at 12 C induced maximal seed sensitivity towards KNO3 + light, and the sensitivity remained unchanged if the incubation at 12 C was extended to 15 days. Upon transfer to 22 C, the effect of low-temperature incubation was lost within 3 days. Of the two seed lots studied, one had a relatively lower chilling requirement, but both had similar requirements for light and KNO3. Gibberellic acids4+7 (GA4+7) induced 100% germination in the dark or light at all temperature regimes. Gibberellic acid3 (GA3) was promotive under isothermal conditions, but its effectiveness was enhanced by a shift in temperature from 12 to 22 C. Kinetin or ethephon, each applied alone, had little effect on germination. Ethephon and GA3 together induced 100% germination.