More Herbicide Diversification Possible with New Materials for Rice

Brian GermanField & Row Crops, Industry

UC Cooperative Extension (UCCE) Rice Crop Advisor, Whitney Brim-DeForest shared recent findings on materials that are proving to be effective in killing a swath of weeds, including broadleaves, sedges, and grasses. Loyant, Cliffhanger, and Zembu provide farmers with new opportunities for further herbicide diversification. 

Herbicide Diversification

Loyant is a foliar-applied herbicide, with the active ingredient florpyrauxifen-benzyl. It suppresses sedges and broadleaf weeds early in the growing season but does not have excellent grass control. “We’re finding it enhances the control of things like propanil and Regiment, (bispyribac-sodium). So, it enhances those two when it’s used as a tank mix,” said Brim-DeForest.

Cliffhanger, with the active ingredient benzobicyclon, is intended for foliar application later in the growing season, treating ricefield bulrush, small flower umbrella-sedges, sprangletop, broadleaves, and grasses. The product already exists in a granular form called Butte. Its efficacy as a tank mix partner is not yet known, research is ongoing. 

Zembu, in its first year on the market, is a granular formation that is applied pre-emergence to control smallflower umbrella sedge and broadleaf. It is used exclusively in water-seeded systems, and “is the only product on the protoporphyrinogen oxidase inhibitor registered that has any activity on grasses at all,” Brim-DeForest said. There is potential for it to be mixed with another granular product for added grass control. 

More herbicide diversification can help to decrease the potential for weed resistance. “I’m encouraging people to try some of these new products because we’ve got new modes of action and new rotational options with of our other products,” Brim-DeForest explained.

UCCE researchers are also going to be looking at the efficacy of hedgerows in rice fields to mitigate weeds. By using native plants, there also is potential to introduce beneficial insects to the field and improve soil quality. UCCE received funding from the California Department of Food and Agriculture and is partnering with a grower whose field borders a canal. 

Researchers will be offering a field day in August for interested rice growers. While the study is ongoing, researchers hope that hedgerows will soon be a viable alternative to chopping, tilling, and spraying fields overgrown with weeds.  

Contributing Author:
Lauren McEwen
AgNet West Intern