Effectiveness of Flumioxazin Alone and in Combination with Glufosinate-ammonium for Control of Parthenium (Parthenium hysterophorus) under Grove Conditions in Homestead, Florida

Abstract

Parthenium hysterophorus L. is a member of the Asteraceae and is indigenous to Mexico, and Central and South America. It is a widely distributed invasive weed in India, Australia, Taiwan, Ethiopia, and in 23 states in the U.S. In Florida, parthenium is found in 24 of the state’s 67 counties. Parthenium invades urban and disturbed areas as well as the vegetable fields and fruit groves throughout southern Miami–Dade County. Roundup PowerMax®, Rely® and Chateau® alone and Rely®plus Chateau® applied in several combinations were investigated in a field trial for their efficacy in controlling parthenium under south Florida grove conditions. Treatments were laid out in a completely randomized design with three replications of each treatment. Parthenium plant population was assessed by counting green live plants within a 361-inch2 grid 1 day prior and 10 times at 15-day intervals after post herbicide application. Data were analyzed as repeated measures analysis using Student’s t-test (alpha = 0.1). Overall, parthenium control was significantly greater for Chateau®plus Rely®treatments compared to Chateau®, Rely® and Roundup PowerMax® alone. In general, Chateau®plus Rely® provided the best parthenium control; however, there was little difference among Chateau® rates. In general, Rely®, Chateau®, and Roundup PowerMax® alone treatments were similar to water control. The best parthenium control required the combination of Chateau®and Rely® at the rates investigated.