Management implications of reduced fallow periods in dryland cropping systems in the Great Plains

The intensification of traditional wheat (Triticum aestivum L.)fallow production systems may have important consequences for management of insects, pathogens, and weeds in Great Plains dryland production systems. Assessment of these consequences is difficult due to the diversity of production systems, environmental conditions, and pests found in the region. Certain pest groups, such as weeds, traditionally controlled during the fallow period, may be favored by intensified cropping while others, such as those specializing on wheat, should be disadvantaged. Changes in pest and disease complexes will likely be evolutionary rather than revolutionary, as has been the case with other significant changes in production practices. Preventive practices in dryland production systems currently emphasize the control of grassy weeds while intensified systems may have less emphasis on the control of volunteer wheat. Crop rotation will remain a key avoidance strategy for pathogens and will help broaden herbicide options. Pest monitoring provides essential information on pest activity and environmental conditions and will become more complex as production systems are intensified. Important suppressive practices for dryland production systems include conservation biological control, tillage, and chemical controls. Chemical control, in particular, is expected to become more complicated due to drift concerns, rotational restrictions, the possible need for herbicide-tolerant crops, and the development of weed populations resistant to glyphosate. Pest management requirements should be considered during cropping system design and establishment.