Efficacy of herbicides against yellow nutsedge (Cyperus esculentus) plants originating from seeds

Abstract

Yellow nutsedge (Cyperus esculentus) is a troublesome weed. It reproduces and spreads mainly via tubers, but also viable seeds are produced. The seeds are very small and have little resources stored. The seedlings are very fragile and look like grasses (poaceae). We hypothesized that C. esculentus plants originating from seeds are more susceptible to herbicides than plants originating from tubers. Cyperus esculentus plants grown from seeds in the greenhouse were treated with glyphosate, bentazone, bromoxynil, pelargonic acid and clethodim. Herbicide efficacy was rated and produced tubers were counted. None of the treatments achieved full control. Four weeks after application a growth reduction of 84% was observed in the glyphosate treatment, whereas bentazone reduced growth by 34% compared to the control. In the other treatments, growth reduction was < 15%. In the glyphosate and bentazone treatment, considerably fewer tubers were produced than in the control. Concluding, we could not confirm our hypothesis. Already 6 weeks after germination seedlings were well developed, tolerant to the sprayed herbicides, except for glyphosate and bentazone, and produced tubers. This implies, that already after a short time Cyperus esculentus stands originating from seeds pose the same problems as the ones originating from tubers.

Keywords

• bentazone
• bromoxynil
• chemical control
• clethodim
• glyphosate
• pelargonic acid