Cuban bulrush (Oxycaryum cubense (Poepp. & Kunth) Lye) is a non-native aquatic plant from South America and the West Indies, first introduced into the United States in 1878. This study focused on the resource allocation and accumulated degree day modeling of the monocephalous and polycephalous Cuban bulrush populations in Mississippi, Louisiana, and Florida. Environmental factors such as photoperiod and temperature were analyzed on its effect on plant growth. From October 2021- September 2022 Cuban bulrush biomass was harvested monthly from two 0.04 Ha (0.1 ac) plots in each state. Height was measured during each monthly event. Environmental monitoring of photoperiod and air temperature were also measured monthly. Starch analyses were completed using the amylase/amyloglucosidase method via a commercially available STA-20 starch assay kit. Linear and polynomial regressions were conducted between Cuban bulrush biomass, starch content, and environmental variables. A Kruskal-Wallis One-Way ANOVA was conducted on total, inflorescence, emergent, and submersed biomass and starch to determine if each state had an effect. Accumulated degree day modeling was done using the Single Sine method by Snyder et al. (1999). Almost all Mississippi biomass and starch had negative relationships with photoperiod and air temperature. All biomass had a significant state effect (P<0.01), while total and emergent starch had a significant effect between Mississippi and Florida (P<0.01). Starch content was not prominent in any one tissue (<1.4% DW). Phenological differences were identified between the monocephalous and polycephalous biotype where the monocephalous had more allocation to total biomass, while the polycephalous focused more on inflorescence. Monocephalous inflorescence peaked in the summer, while polycephalous peaked in the winter. Model results show base threshold temperatures below 0°C, and the potential of Cuban bulrush to expand north. Future recommendations include future growth studies based on modeling data from this study.
Date of Degree
Master of Science (MS)
Program of Study
Science, Engineering and Technology
Squires, Allison. (2023). Seasonal Resource Allocation and Accumulated Degree Day Estimation for Cuban Bulrush (Oxycarum cubense) in the Southeastern U.S. [Master’s thesis, Minnesota State University, Mankato]. Cornerstone: A Collection of Scholarly and Creative Works for Minnesota State University, Mankato. https://cornerstone.lib.mnsu.edu/etds/1395/
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