Loyant® CA Section 2(ee) Recommendation Bulletin for Control of Cattail in Rice

A recommendation bulletin has been released for florpyrauxifen-benzyl (Loyant® CA, Corteva Agriscience LLC, Indianapolis, IN, USA) to control cattail plants in California rice fields and permitted under FIFRA Section 2(ee). Cattail (Typha latifolia L.) also known as common cattail or broadleaf cattail is a perennial wetland weed that naturally occurs widely in nearly all North America and are often considered undesirable, weedy, or invasive. Common cattail is cosmopolitan weed that can grow up to 10-ft tall under favorable conditions. Common cattail has recently been more problematic in the drill-seeded rice systems of the River Delta in California, where common cattail patches infested rice fields in short time intervals. Therefore, we studied the potential use of newly registered rice herbicide, Loyant® CA, on the control of common cattails when applied at different timing.

 Cattail control with Loyant^® CA at 1.33 pint/A treated plot at 14 days after herbicide application in 2023.

Two field studies were carried out in 2022–2023 at McDonald Island of Sacramento-San Joaquin River Delta. The 2,400-ha island is bounded on the north by San Joaquin River, on the west by Middle River and Latham Slough, and on the south by Empire Cut. The rice fields were at Stockton, CA. Experiments were conducted as a randomized complete block design, with four replicates, where a 3-m by 3-m rice plot was an experimental unit. Herbicide treatments included Loyant® CA at 1.33 and 2.66 pint/A rates at different cattail growth stages.

All Loyant® CA treatments regardless of application rate or timing resulted in 100% cattail control at 28 days after treatments. None of the treatments caused a significant rice injury. Loyant® CA at 1.33 pint/A controls 100% of up to 3-ft tall. For taller cattails from 3-ft to 6-ft, a sequential application of Loyant® CA within 14-days intervals at 1.33 pint/A may be required. The Section 2(ee) Recommendation Bulletin states the following use directions. For control of cattail in rice fields, apply Loyant® CA at 1.33 pint/A plus 0.5 pint/A MSO as a broadcast spray to cattail plants up to 3-ft tall. Apply in sufficient water to provide good coverage of the cattail without washing spray solution from leaves. A second application may be made if needed with a minimum retreatment interval of 14 days.