Flumioxazin herbicides have been used as an agricultural chemical since 2001, and was conditionally registered for aquatic use in 2010. The active ingredient is 2-[7-fluoro-3,4-dihydro- 3-oxo-4-(2-propynyl)-2H-1,4-benzoxazin-6-yl]- 4,5,6,7-tetrahydro-1H-isoindole-1,3(2H)-dione. It is available in granular form (Clipper™) for control of submerged plants, and can be used as a direct foliar application to control emergent and floating-leaf plants. It also controls some filamentous algae.
Aquatic Use and Considerations
Flumioxazin is a broad-spectrum contact herbicide. It works by interfering with the plants’ production of chlorophyll. Treated plants will respond quickly to treatment and rapidly decompose. For larger treatments or in dense vegetation, split treatments about two weeks a part are recommended to prevent fish suffocation from low oxygen due to decaying plants.
Flumioxazin needs to be applied to young plants early in the spring as they begin to grow. It should not be used in very hard-water lakes (pH over 8.5), many of which occur in southeastern Wisconsin. Application in the early morning will increase efficacy, particularly in hard-water lakes. A water body should not be treated with flumioxazin if there is an outlet, or in moving waters such as rivers or streams.
Flumioxazin controls invasive Eurasian watermilfoil (Myriophyllum spicatum) and curlyleaf pondweed (Potamogeton crispus). It may also affect desirable native species, such as coontail (Ceratophyllum demersum), duckweeds (Lemna spp.), some pondweeds (Potamogeton illinoensis, P. diversifolius, Stuckenia pectinata) and native milfoil (M. heterophyllum).
Note: Products may not be registered for use in your state or locale. Check to be sure a specific use pattern is approved in your area before use. Check product labeling or your local state agency for more information. Most current product labels are available by visiting the product manufacturers website or at https://www.cdms.net