The Fitness Cost of Triazine Resistance in Jimsonweed (Datura stramonium L.)

-Fitness costs of herbicide resistance are incompletely known, but may be exploited to prevent or manage evolution of herbicide-resistant weeds. The fitness cost of a chloroplast gene encoding triazine resistance was estimated in jimsonweed (Datura stramonium L.) by growing resistant and susceptible plants from germination to maturity in the field, with and without a neighbor planting of maize (Zea mays L.). Resistant types produced 57% of total aboveground biomass production and 42% of reproductive biomass production of susceptible types. The cost of resistance was distinctly increased by the presence of maize, suggesting that crop interference may be a useful tool for selecting against triazine-resistant weeds.