Selection of meadow fescue for persistence under frequent defoliation

Abstract

Background

Meadow fescue (Schedonorus pratensis (Huds.) P. Beauv.) is a reemerging pasture grass for temperate regions of North America. One disadvantage of this species is its lack of tolerance to frequent defoliation at low residual sward heights. This experiment was designed to conduct one cycle of selection and evaluation for persistence under frequent defoliation.

Methods

The experiment included four locations with intensive grazing: two on silt loam soils and two on loamy sand soils. A fifth location was managed with frequent mowing to a 5-cm residual sward height, approximately 12–15 mowings per year. One cycle of selection was conducted with a population size of 1000 plants and 20 plants were selected for survivorship and vigor. Seed of all selected populations was evaluated at all five selection locations.

Results

Gains were made in all eight populations, both due to increases in endophyte infection frequency and genetic gains associated with improved host genotypes. Selection was successful on both silt loam and loamy sand soils, but none of those gains were realized on the alternate soil type. Selection was successful at two of the four grazing farms, the two located on silt loam soils, but these gains were not realized on the farms with loamy sand soils or under the frequent mowing method of defoliation.

Conclusions

Selection for tolerance to intensive grazing should be conducted under grazing conditions and selection for adaptation to both sandy and silt loam soils will require a more complex and imaginative selection scheme.