Degree

Doctor of Philosophy (PhD)

Department

Plant, Environmental Management and Soil Sciences

Document Type

Dissertation

Abstract

Field studies were conducted in 2018-2021 at the LSU Agricultural Center’s H.R. Caffey Rice Research Station (RRS) near Crowley, LA, and the Dean Lee Research and Extension Center (DLREC) near Alexandria, LA to evaluate off-target florpyrauxifen movement on soybean. Soybean was treated with florpyrauxifen at the V4-V5 or R1-R2 growth stages. Soybean injury was evaluated at 1, 7, 14, and 28 days after treatment (DAT) and soybean plant height (cm) was recorded at 7, 14, and 28 DAT. At soybean maturity, yield and individual yield components were subjected to regression analysis to describe the relationship between florpyrauxifen rate and soybean yield. Crop injury was observed at all evaluation dates. Soybean yield was reduced with florpyrauxifen applied at 1.84 g ha-1 at the V4-V5 timing and florpyrauxifen applied at 0.46 g ha-1 or more at the R1-R2.

Field studies were conducted in 2019 and 2020 at the RRS and the DLREC to evaluate florpyrauxifen volatilization following an application to rice foliage, exposed soil, or exposed water. Soybean was the bioindicator, treated application media was placed in the center of plots and distance moved was measured via injury ratings at 31 cm increments. Results indicated that florpyrauxifen has minimal volatilization with injury observed at 31 cm from the plot center with no differences between medias.

Field studies were conducted in 2019 and 2021 at the RRS and the Northeast research station (NERS) near St. Joseph, LA to evaluate quizalofop activity on rice. Two inbred lines and a hybrid rice were treated with quizalofop applied at 0 to 116 g ha-1 to rice in different growth stages. Control and plant heights were recorded 7, 14, 21, and 28 DAT. Control was 90 to 99% when CL-111 and CLXL-745 were treated with quizalofop at least 23 g ha-1 at the two- to three-leaf (lf) timing and when Mermentau was treated with quizalofop at 46 g ha-1 or more at PI.

Date

3-9-2022

Committee Chair

Webster, Eric

DOI

10.31390/gradschool_dissertations.5763

Available for download on Friday, March 10, 2023

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