Penoxsulam 2.5% 10% OD weedicide agricultural chemicals weed control herbicide agrochemical pesticide

                                                                                   Penoxsulam

Penoxsulam was registered with the EPA for aquatic use in 2009.

The active ingredient is 2-(2,2-difluoroethoxy)—6-(trifluoromethyl-N-(5,8-dimethoxy[1,2,4] triazolo[1,5,-c]pyrimidin-2-yl)) benzenesulfonamide).

It is a liquid and is used for large-scale control of submerged, emergent and floating-leaf vegetation.

Aquatic Use and Considerations

Penoxsulam is a systemic herbicide that moves throughout the plant tissue and prevents plants from producing a necessary enzyme, acetolactate

synthase (ALS), which is not found in animals. Susceptible plants will stop growing soon after treatment and become reddish at the tips of the

plant. Plant death and decomposition will occur gradually over several weeks to months. Penoxsulam should be applied to plants that are actively

growing; mature plants require a higher concentration of herbicide and a longer contact time.

Penoxsulam must remain in contact with plants for around 60 days. A supplemental “bump” treatment may be needed to maintain the herbicide

concentration for the required contact time. Because of this long contact period, penoxsulam is likely to be used for larger-scale or whole-lake

treatments and should not be used where rapid dilution can occur such as spot treatments or moving water.

Penoxsulam may be used to treat the invasive Eurasian watermilfoil (Myriophyllum spicatum). In other parts of the country, it is valuable as a

rotational herbicide against the invasive plant hydrilla (Hydrilla verticillata). Desirable native species that may also be affected include sago

pondweed (Stuckenia pectinata), Illinois pondweed (Potamogeton illinoensis), pickerelweed (Pontederia cordata), duckweeds (Lemna spp.) and

arrowhead (Sagittaria spp.).

It is important to note that repeated use of herbicides with the same mode of action can lead to herbicide-resistant plants, even in aquatic plants.

More resistant weeds have developed to the ALS inhibitor herbicides than to other herbicide types, and so this mechanism of action may be more

susceptible to developing resistance. In order to prevent herbicide resistance, avoid using the same type of herbicides year after year, and when

possible, use non-herbicide methods of control instead.

Penoxsulam is a new post-emergence rice herbicide for applications in drained and semi-flooded paddies. It is an acetolactate synthase inhibitor herbicide developed in the mid-2000s. This substance is designed to control existing broadleaf weeds and similar plants in lawns, rice fields and cereal crops. While penoxsulam is not effective against most grass species, it can be used to control a few specific weed grass species. Penoxsulam was originally designed for use in rice fields and is capable of killing several pest grasses that prefer wet environments.

We have successfully synthesized standards of the Penoxsulam. This will be of interest to agrochemical companies and analytical labs.