With warmer days comes a new flush of weeds competing with your rice crop for water and nutrients. Control of grasses and broadleaves can improve your potential yield and harvest efficiency.

Below are management tips for perpetual problem weeds.

Barnyardgrass
A summer annual grass, barnyardgrass grows in clumps. It can be identified by its hairless flat stem and a first true leaf that is wide and rounded at the tip.

Known resistance: There is widespread documentation of barnyardgrass resistance to multiple herbicide modes of action, including PSII inhibitor (propanil), synthetic auxins (fenoxaprop and quinclorac), ACCase inhibitors, DOXP inhibitors (clomazone), ALS inhibitors and cellulose inhibitors (quinclorac).

Recommendations: Pre-flood options include Loyant™ herbicide at a rate of 1 pint per acre or RebelEX^® herbicide at a rate of 18 fluid ounces per acre. Additionally, Grasp^® SC herbicide at a rate of 2 fluid ounces per acre applied early postemergence will control barnyardgrass.

Rice flatsedge
While often confused with other sedges, rice flatsedge has leaves that are narrower than yellow nutsedge leaves. Rice flatsedge plants often grow more densely, and their fibrous roots, when crushed, have a sweet odor.

Known resistance: Resistance to ALS inhibitors has been documented in the rice-growing states of Arkansas and Louisiana.

Recommendations for control: A pre-flood application of either Loyant™ herbicide at a rate of 1 pint per acre, RebelEX^® herbicide at a rate of 18 fluid ounces per acre or Grasp^® SC herbicide at a rate of 2 ounces per acre applied early postemergence will provide control.

Yellow nutsedge
Reproduced by tubers instead of seed, yellow nutsedge has broader leaves and thicker stems than rice flatsedge. The two species are noticeably different when flowering with yellow nutsedge flowers a light brown or yellow color and larger than other sedges.

Known resistance: Resistance to ALS inhibitors was documented in Arkansas in 2013.

Recommendation: A pre-flood application of either Loyant™ herbicide at a rate of 1 pint per acre, RebelEX^® herbicide at a rate of 18 fluid ounces per acre or Grasp^® SC herbicide at a rate of 2 ounces per acre applied early postemergence will provide control.

Amazon sprangletop
An annual grass with no hairs on the leaf blade, Amazon sprangletop grows up to 4 feet tall and prefers moist soils.

Known resistance: Amazon sprangletop resistance to ACCase inhibitors has been documented in Louisiana rice.

Recommendation: Control options for Amazon sprangletop include Clincher^® herbicide at a rate of 10 ounces per acre applied early postemergence or RebelEX^® herbicide at a rate of 18 fluid ounces per acre at pre-flood. RebelEX provides both postemergence control and residual activity.

Hemp sesbania
Hemp sesbania is easily identifiable by its green, branching palm-like leaves. This late-season emerging broadleaf reaches 3 to 13 feet tall at maturity. It is also known as coffeeweed or coffeebean.

Known resistance: No documented resistance.

Recommendation: A pre-flood application of Loyant™ herbicide at a rate of 1 pint per acre is recommended.

Visit LoyantProtects.com for more information on Loyant herbicide.

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