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K. Stump, UF/IFAS Extension, Osceola County, Kissimmee, FL

Situation: Land managers rely on herbicide to control invasive species in natural areas. However, improper application can have unintended environmental impacts and waste time, money, and resources. In addition, there can be legal consequences for not properly following an herbicide label. Herbicide workshops for continuing education units often incorporate equipment calibration but may not review the math needed to properly mix herbicide per label requirements. The objective of the program was to increase knowledge about herbicide mixing math by 30%.

Methods: An interactive herbicide mixing math session was incorporated into three herbicide workshops in 2019 and 2020 in Lake and Osceola Counties. The sessions began with a presentation of step-by-step guidance through common math problems needed to mix herbicides. The attendees were then challenged to solve the problems individually, in pairs, and in groups to ensure all types of learners had the opportunity to practice. The session provided tips, used color-coded steps, and used repetition to better facilitate learning.

Results: In total, 140 adults attended the workshops. A pre-/post-test was used to measure knowledge gain at two of the three sessions. The respondents (n=86) reported a 33% increase in knowledge about herbicide mixing math.

Conclusion: Through a better understanding of the math required to mix herbicides, professionals are able to better follow label requirements. This in turn protects the environment, reduces waste, and improves personal safety.


  1. It is astounding the impacts that results from proper label reading. Well done on your educational program and impacts.

  2. Important classes – important outcomes.

  3. Will you be able to followup with attendees to see how much they have improved their practices after attending the class?

    • Hi Liz, great question. Yes, I will conduct a follow-up Qualtrics survey for behavior change outcomes in the fall.