THE GENECOLOGY OF LAWN WEEDS

Abstract

Results from an experiment in which trampling was simulated indicated that in Plantago major and Poa annua the genetically‐determined prostrate growth forms were in general better able to withstand trampling damage than the corresponding erect growth forms. The effects of trampling stress were found to differ between species, between treatments for each species, and in the degree to which different aspects of growth and reproduction appear to be affected within a given species. Estimates of coefficients of selection acting against the erect growth forms were particularly high for reproductive characters, with values of 0.78 to 0.79 for Plantago major and 0.46 to 0.66 for Poa annua. Problems in the design of experiments investigating trampling stress are discussed.