12 Feb 2026

Growth Patterns of Three Hydrilla Verticillata Biotypes in the United States

Abstract: Hydrilla [Hydrilla verticillata (L.f. Royle)] is an invasive submersed plant first documented in the United States (US) in the 1950s. Until recently, only two distinct strains of hydrilla, hereafter referred to as biotypes, were recorded in the US with both belonging to the same clade and characterized as either ‘monoecious’ or ‘dioecious’. In 2016, a third genetically distinct biotype (‘clade C’) was identified in the lower Connecticut River, Connecticut. Trials were conducted at two geographically unique locations within North Carolina to compare growth and reproduction of hydrilla biotypes by climatic conditions. Nominal differences were observed in peak aboveground biomass, relative growth rate, or occurrence of these metrics among the three hydrilla biotypes, although the predicted peak biomass for dioecious hydrilla did not occur during the study period. Monoecious hydrilla exhibited lower peak belowground biomass than dioecious and clade C hydrilla despite its abundant subterranean turion production. Monoecious hydrilla exhibited 1.8X greater aboveground biomass 180 days after planting (Julian day 304) than clade C hydrilla. Clade C hydrilla produced 74 axillary turions per plant on Julian day 304, which equates to a 2.3X increase over monoecious hydrilla and 61.5X increase over dioecious hydrilla. Conversely, subterranean turion production was 4.7 and 7.1X higher in monoecious hydrilla and dioecious hydrilla than clade C hydrilla, respectively. These studies suggest the clade C hydrilla displays many phenological similarities to the other two biotypes in the US, but its prodigious axillary turion production poses concerning implications for potential to spread and persistence following management.

3 May 2021

Developmental position to offer growth, new skills for USACE employee

Many U.S. Army Corps of Engineers employees are eager to learn new skills and grow in their position. Fortunately, the Memphis District oftentimes offers opportunities for its employees to do just that through what's called developmental assignments and/or positions. A developmental position is a temporary job that differs from their permanent position and is designed to train and develop employees in preparation for further career advancement. These temporary positions normally last about 120 days, but can be shorter or longer depending on the position. Additionally, the job location can either be at the employee’s home station or in a completely different state. While the differences vary from position to position, one thing remains the same, the benefits of working a developmental assignment are endless. Recently, Memphis District Procurement Analyst TiJuana' TJ' Harris was provided the chance to apply for a 120-day developmental assignment at the division level, where she said she would learn even more about the "whys" of USACE contracting.