Differences in growth and herbicide sensitivity among Cyperus esculentus clones found in Belgian maize fields

Abstract

Cyperus esculentus is an invasive troublesome neophyte in many arable crops in Belgium. Applied weed control varies from field to field. One of the possible reasons for this variability might be a differential vegetative and reproductive behaviour among Belgian C.esculentus clones. In this study, growth characteristics and herbicide sensitivity of C.esculentus clones collected in Belgian maize (Zea mays) fields were evaluated. In a morphology Experiment, 25 clones were screened for growth characteristics and ability to set viable seeds under outdoor conditions. Dose-response experiments were conducted in the glasshouse to evaluate the effectiveness of two foliar-applied herbicides (bentazon and glyphosate) and two pre-sowing soil-incorporated herbicides (S-metolachlor and dimethenamid-P) for controlling 14 C.esculentus clones. Response variables were aboveground dry biomass, tuber number, tuber dry biomass and individual tuber dry weight. Clones exhibited large differences in shoot number (up to 3.1-fold), tuber dry biomass (up to 4.7-fold), tuber number (up to 3.4-fold), individual tuber dry weight (up to 4.8-fold), inflorescence number and capacity to set viable seeds. Large interclonal differences in herbicide sensitivity (up to 8.3- and 4.0-fold for aboveground dry biomass and tuber dry biomass, respectively) were observed. Contrary to foliar-applied herbicides, soil-incorporated herbicides were very effective and provided season-long C.esculentus control at doses below the recommended maximum field dose. However, low doses stimulated tuber formation. Future C.esculentus management strategies should take into account differential growth characteristics and herbicide sensitivity of C.esculentus clones