Effect of prior common reed (Phragmites australis)cutting on herbicide efficacy

The study evaluated the effect of prior plant cutting of common reed (Phragmites australis), during flowering, on the efficacy of isopropylamine and trimesium salts of glyphosate (2.9 and 2.6 kg a.i./ha, respectively) applied at two spray volumes in the following spring. Efficacy was measured by plant cover (% control), number of plants/m2 and plant biomass/m2. A positive effect of the plant cutting was observed when plant cover and number of plants/m2 were measured. The evaluation of herbicide phytotoxicity on plant biomass did not show significant differences. Common reed susceptibility to isopropylamine and trimesium salts of glyphosate was similar. Significant differences between the spray volumes of 320 and 400 l/ha were observed only in plant cover estimates. The 400 l/ha spray volume showed higher efficacy.