Degree

Doctor of Philosophy (PhD)

Department

Plant, Environmental, and Soil Science

Document Type

Dissertation

Abstract

Abstract

Field studies were conducted in 2018 at two locations at the H. Rouse Caffey Rice Research Station (RRS) to evaluate the activity of titrated rates of florpyrauxifen-benzyl on aquatic weeds. Florpyrauxifen-benzyl was applied at 0, 3.6, 7.3, 11, 14.6, 18.3, 22, 25.6, and 29.5 g ai ha-1into 91-cm diameter galvanized rings containing ducksalad, alligatorweed, cattail, creeping water primrose, grassy arrowhead, and pickerelweed. Ducksalad control was 89 to 99% when treated with all rates of florpyrauxifen at 11 to 29.5 g ha-1; however, control was reduced to 51 to 79% when treated with rates lower than 11 g ha-1.

Three field studies were conducted at the RRS in 2017 and 2018 evaluating the interactions of florpyrauxifen-benzyl mixed with graminicides, ALS-inhibiting, or contact herbicides. Little to no antagonistic interactions were observed for barnyardgrass treated with florpyrauxifen mixed with graminicides. Antagonistic interactions were observed for barnyardgrass activity when treated with florpyrauxifen mixed with all ALS-inhibiting and contact herbicides. Severely antagonistic interactions were indicated by barnyardgrass treated with florpyrauxifen mixed with propanil or orthosulfamuron.

Field studies were conducted in 2017 and 2018 to evaluate the activity of florpyrauxifen-benzyl and a prepackaged mixture of halosulfuron plus prosulfuron compared with other products applied at a late-season salvage timing. At 42 DAT, yellow nutsedge, hemp sesbania, and Indian jointvetch control was greater than 97% when treated with halosulfuron at 53 g ai ha-1. A similar response was observed for these weeds when treated with florpyrauxifen-benzyl or halosulfuron plus prosulfuron. Alligatorweed control was 99% when treated with florpyrauxifen at 29 g ha-1. Similar control was observed with florpyrauxifen applied at 14.5 g ha-1. Similar control was observed at 42 DAT when alligatorweed was treated with halosulfuron plus prosulfuron at 55 or 83 g ai ha-1.

Date

11-9-2020

Committee Chair

Webster, Eric

Included in

Agriculture Commons

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