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Applied Research

Clay Cooper
Agriculture and Natural Resource Agent
UF/IFAS Extension Citrus County


  Brunswickgrass (Paspalum nicorae Parodi), is a problematic weed in summer perennial grass pastures in the southeast. In Florida we have seen increasing pressure to control this weed contaminate as it is becoming a major threat to livestock and bahiagrass seed industries. This rhizomatous grass is refused by cattle and seed could potentially restrict sales of contaminated bahiagrass seed lots further. Bahiagrass seed contaminated with brunswickgrass has been denied distribution in Australia and other countries where bahiagrass seed has been imported from the U.S. This presents a major problem for the bahiagrass seed industry with an estimated $18 million in annual seed sales. Currently, management options are limited; therefore, the objective of this research is to develop a management plan for Brunswickgrass in Bahiagrass seed production fields. In 2019, an application timing study was established assessing control differences between month and rate. Applications were made monthly starting in May until September at rates of 0.56, 0.84, and 1.12 kg ai ha-1. In the timing study, there was no rate by month interaction at 30 or 365 DAT, however, both month and rate were significant. Hexazinone at 0.56, 0.84, and 1.12 resulted in 81, 85, and 95% control at 30 DAT. Application of hexazinone in May resulted in the lowest level of control (63%), but all other application timings resulted in control of at least 86%. At 365 DAT, 0.56 kg ha-1 resulted in 56% control, and at least 74% control was achieved with the higher rates. Similar to 30 DAT, the May application timing resulted in the lowest level of control by 365 DAT (34%), whereas all other timings resulted in similar levels of control of at least 71%. Overall, these results are promising in the fact that we are seeing some initial success using hexazinone for Brunswickgrass management. However, it is evident that multiple annual applications may be necessary to deplete the soil seed bank. Also, applications should not be made prior to June for optimal activity.

Poster has NOT been presented at any previous NACAA AM/PIC

This poster is being submitted for judging. It will be displayed at the AM/PIC if not selected as a State winner. The abstract will be published in the proceedings.

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Authors: C. Cooper, Sellers Brent, Wallau Marcello, Devkota Pratap
  1. Cooper, C. Agriculture and Natural Resource Agent, UF/IFAS Extension Citrus County, Florida, 34461
  2. Brent, S. Professor and Director, UF/IFAS Range Cattle Research and Education Center, Florida, 33865
  3. Marcello, W. Assistant Professor/Forage Extension Specialist, UF/IFAS Agronomy Department, Florida,
  4. Pratap, D. Assistant Professor/Weed Scientist, UF/IFAS West Florida Research and Education Center, Florida, 32565