Because environmental factors facilitating the breaking of dormancy of seed of catclaw mimosa (Mimosa pigra L. ♯ MIMPI) under field conditions were unknown, the effect of constant temperatures (2 to 44 C) on germination of scarified and unscarified seeds, and the effect of diurnally fluctuating temperatures on unscarified seeds were examined. Temperatures fluctuated diurnally by 10 and 20 C in these latter experiments. Germination was less than 10% at all constant temperatures except 44 C, which had 40% germination. Scarification increased germination to 100% at constant temperatures greater than 12 C. Germination of unscarified seed was significantly lower (0 to 23%) when day/night temperature ranges fluctuated by 10 C than when they fluctuated by 20 C. Optimum temperature for germination was 40/20 C, where 93% germination occurred within 4 days.
