The EPA has registered Rogue SC, a rice herbicide from Gowan Co., LLC for use on flooded rice in three Midsouth/Delta states — Arkansas, Louisiana and Missouri. Registration is also pending for Mississippi, Tennessee and Texas, according to the company’s website. 

Rogue SC is a broad-spectrum herbicide, controlling key grass, broadleaf, aquatic and sedge species in rice. In 2019-2020, Rogue received experimental use permits in Arkansas and Louisiana. Also, in April 2021 Rogue SC received a Section 18 emergency exemption to be applied in Arkansas to combat the spread of weedy rice. That exemption expired in August. 

The full federal registration will likely be welcome news to rice farmers looking to manage weeds that are hard to control with other herbicides — particularly for growers working to combat the spread of weedy rice, although experts say it should not be considered a stand-alone product for weedy rice suppression. 

Rogue herbicide

Rogue brings a brand new mode of action to rice fields in the Midsouth. The active ingredient in Rogue SC is benzobicyclon. An oversimplified explanation of how the product works is that when benzobicyclon is applied to a flooded rice field, it converts to an HPPD inhibiting herbicide that affects pigment synthesis in the targeted weeds. This process results in bleaching, growth reductions and, eventually plant death. 

Water is necessary to activate the herbicide. In fact, Rogue is only active in floodwater and has no herbicidal activity when applied to soil or plant foliage. It was specifically created for use in rice and has no fit in any other crop. 

Because of the novel nature of the herbicide, applicators are strongly encouraged to complete an online training and certification before using the product. The training can be found on Gowan’s website. (gowanco.com/rogue-sc) Certified Crop Advisors will earn 0.5 CEUs in Soil and Water Management upon completion. 

For optimum results 

Rogue SC is labeled for both dry-seeded and water-seeded rice. Optimum results are obtained when targeted weeds are completely submerged at the time of application and remain submerged. Complete control typically occurs within 7 to 21 days depending on the weed species, size and temperature. A deep and static flood is critical following applications, according to the label. Growers should avoid introduction of additional water for at least five days following application. 

For pre-emergence applications, the label recommends applying Rogue SC as soon as a stable 3-to-4-inch flood is established. 

Side-inlet irrigation and zero-grade bays are ideal for maintaining herbicide distribution within each bay of a rice field. The use of Rogue SC on fields with gravity irrigation and short distances between levees should be avoided. If the flood is lost following application of ROGUE SC, re-establish the flood before the soil dries to reduce loss of herbicidal activity. 

In addition to weedy rice, Rogue controls a number of weeds, including Amazon and bearded sprangletop, ducksalad, rice flatsedge and ricefield bulrush, and barnyardgrass. 

Rogue is compatible with the Clearfield, FullPage, Provisia and Max-Ace systems.