Enhancing the seed germination process of Montezuma cypress (Taxodium mucronatum Ten.)

Montezuma cypress (Taxodium. mucronatum) is an ecological, cultural and economically valuable riparian tree species. Two experiments evaluating the effectiveness of various seed treatments were conducted to identify germination best practices and to evaluate the dynamics of the germination process. Seeds were collected on two occasions, one year apart, from the only remaining natural T. mucronatum tree stand in the United States. The seeds were subjected to various soaking and stratification conditions. Across all treatments, germinability ranged between approximately 30%-40%, with slightly higher values occurring among the second seed cohort. Overall, no significant differences in germinability were detected in either study, however, soaking seeds in water for 96 hours and stratifying them in moist conditions for 3 weeks significantly accelerated the germination process. Seeds soaked briefly in a NaOH solution followed by a 48-hour water soak demonstrated more synchronous germination than other treatments. Control conditions in which seeds were not soaked or stratified exhibited the slowest germination. These findings are consistent with previous evidence showing that T. mucronatum seeds do not exhibit physiological dormancy and that treatments promoting seed water imbibition enhance the germination process. This study adds to the limited available research on T. mucronatum propagation practices and offers novel data on the germination parameters of seeds sourced from a natural U.S. stand, rather than seeds from few scattered individual trees, as in previous reports. Seed germination recommendations garnered from this study can improve nursery production of T. mucronatum to enhance ecological restoration efforts and ornamental production.