EFFECTS OF ENVIRONMENTAL-STRESS ON WEED CROP INTERACTIONS/

All environmental factors that influence plant growth potentially can affect the ability of weeds and crops to exploit the environmental res ources for which plants compete, Stressful levels of environmental fac tors such as temperature, light, and water and nutrient availability i nfluence weed/crop interactions directly and also may interfere with ( or enhance) weed control. Weed and crop species differing in photosynt hetic pathway (C-3 VS C-4) are likely to respond differently to many o f these factors. Long-term changes in the atmospheric concentrations o f CO2 and other radiatively-active ''greenhouse gases'' may exert dire ct physiological and indirect climatic effects on weed/crop interactio ns and influence weed management strategies. This review focuses on th e effects of temperature, light, soil nutrients, water stress, and CO2 concentration on weed/crop interactions with consideration of the pot ential impact of climate change.