EVALUATION OF METSULFURON METHYL FOR SELECTIVE CONTROL OF LYGODIUM MICROPHYLLUM GROWING IN ASSOCIATION WITH PANICUM HEMITOMON AND CLADIUM JAMAICENSE

• Published in: Florida scientist 2006-07, Vol.69 (3), p.149-156
• Main Authors: Langeland, K. A., Link, M. L.
• Format: Article
• Language: English
• Subjects: Agricultural management; Biomass; Cephalanthus occidentalis; Cladium jamaicense; Ferns; Habitats; Herbicides; Invasive species; Lygodium microphyllum; Native plants; Panicum hemitomon; Plants; Regrowth; Vegetation
• ISSN: 0098-4590

A study was conducted to evaluate the effectiveness of the herbicide active ingredient metsulfuron methyl for controlling the invasive Old World climbing fern Lygodium microphyllum and to determine injury to the non-target, native species Panicum hemitomon. Based on visual ratings, metsulfuron methyl provided 94% control of L. microphyllum 23 months after two applications of 84 g a.i./ha, while 67% control was observed in plots treated twice with 42 g a.i./ha (LSD .05 = 10). Eighty three percent control was observed 18 months after application in plots treated only once with 84 g a.i./ha. Twenty eight months after the final herbicide application, L. microphyllum dry weight was not different in treated plots compared to untreated plots. Based on visual observations, injury to P. hemitomon was not observed in these same plots, and biomass, though highly variable, was not reduced in treated plots compared to untreated plots. A separate study was conducted to determine injury to Cladium jamaicense, which is a dominant non-target, native plant in some habitats invaded by L. microphyllum. Visual injury to C. jamaicense was not observed during a complete growing season after treatment with up to 168 g a.i./ha metsulfuron methyl. After cutting of C. jamaicense the following growing season, regrowth in plots treated with 42, 84, or 168 g a.i./ha metsulfuron methyl was 164, 124, and 126 g/m2, respectively, and was not significantly reduced compared to untreated plots that contained 181 g/m2 of regrowth (LSD .05 = 62). Results of this study indicate that metsulfuron methyl applied at a rate of 84 g a.i./ha will subdue growth of L. microphyllum for at least one growing season and two consecutive applications will offer slightly greater control. However, complete control is not achieved and additional control measures will be required to keep growth in check. C. jamaicense, or P. hemitomon, which are common non-target plant species in some habitats where L. microphyllum has invaded will not be affected and permanent damage will not occur to Cephalanthus occidentalis when metsulfuron methyl is applied for control of L. microphyllum.