Effects of Environmental Stress on Weed/Crop Interactions

Abstract

All environmental factors that influence plant growth potentially can affect the ability of weeds and crops to exploit the environmental resources for which plants compete. Stressful levels of environmental factors such as temperature, light, and water and nutrient availability influence weed/crop interactions directly and also may interfere with (or enhance) weed control. Weed and crop species differing in photosynthetic pathway (C3vs C4) are likely to respond differently to many of these factors. Long-term changes in the atmospheric concentrations of CO2and other radiatively-active “greenhouse gases” may exert direct physiological and indirect climatic effects on weed/crop interactions and influence weed management strategies. This review focuses on the effects of temperature, light, soil nutrients, water stress, and CO2concentration on weed/crop interactions with consideration of the potential impact of climate change.

Modelling crop-weed competition: Why, what, how and what lies ahead?

“…In a simple case, we may want a model that can predict the likely yield loss associated with different weed densities in our crop. In reality, this yield loss is likely to depend on many factors besides the density of the weed, such as the weed species and ecotype; the emergence time of the weed cohorts relative to the crop emergence time; soil nutrients; the competitiveness of the species and cultivar of the crop being grown; or the rainfall and temperature experienced in the field over the growing season (Zimdahl, 2004;Patterson, 1995). So instead of the simple model described above, we might want a more sophisticated model that can predict the likely yield loss associated with different weed densities in our crop, while accounting for all these other factors as well.…”

Invasive species and climate change: an agronomic perspective

“…Overall, changes in the timing and amount of precipitation are likely to alter a number of biological aspects of invasive weeds including germination, plant size, seed production, and the distribution of water borne seeds. At the community level it is probable that precipitation extremes will favor competition between invasive weeds and crops with subsequent negative effects on crop productivity (Patterson 1995b).…”

Does temperature regulate light quality effects on Abutilon theophrasti?

“…Due to increasing levels of greenhouse gases in the atmosphere, global average temperatures have been forecast to rise 1.4-6.4°C by the year 2100 (Solomon et al 2007). It is likely that global warming will alter the effects of other environmental factors on both weeds and crops (Patterson 1995a). …”