Semester of Graduation

Spring 2025

Degree

Master of Science (MS)

Department

Plant, Environmental, and Soil Sciences

Document Type

Thesis

Abstract

A field study was conducted at the H. Rouse Caffey Rice Research Station (RRS) in 2023 and 2024 to evaluate crop safety when quizalofop applications were made on ‘PVL03’ before and after overcast growing conditions. Factor A (main plot) consisted of no shade, shade for a period of 7 days prior to quizalofop application, or shade for a period of 7 days after quizalofop application. Factor B (sub plot) consisted of shade coverage representing simulated overcast weather at 0, 30, 60, or 90%. Factor C (sub-sub plot) consisted of no quizalofop, quizalofop at 120 g ha-1, or quizalofop at 240 g ha-1. In general, rice injury was observed when simulated overcast weather was present before and after quizalofop applications. Additionally, the results of this study suggest that crop response is light dependent and higher injury can be expected when overcast growing conditions are present after a 120 g ha-1 application of quizalofop.

A field study was conducted at the RRS in 2024 to evaluate crop safety of fluridone applications on five rice lines. The rice varieties evaluated consisted of ‘PVL03’, Jupiter, and Avant and the hybrids evaluated consisted of ‘RT7321’ and ‘RT7523’. Factor A consisted of rates of fluridone at 0, 84, 126, and 168 g ha-1. Factor B consisted of five application timings targeting preemergence (PRE), delayed preemergence (DPRE), 1-2 leaf rice, 3-4 leaf rice, and preflood. Fluridone applications made at PRE resulted in the highest frequency of rice injury and yield loss across all rice lines evaluated. Similarly, applications of 168 g ha-1 of fluridone resulted in the highest frequency of injury at each application timing and should be avoided. DPRE applications across all flooded rice trials showed that lower rates caused less yield loss. Fluridone applied on 1-2 and 3-4 leaf rice resulted in greater yields than PRE and DPRE applications of fluridone. Preflood applications were the safest applications across flooded and furrow-irrigated rice resulting in minimal yield loss in comparison to the check.

Date

4-23-2025

Committee Chair

Webster, Lucas

Download

Share

COinS