Confronting herbicide resistance with cooperative management

Area of Science:

• Agricultural Science
• Ecology
• Evolutionary Biology

Background:

• Pest and pathogen resistance to pesticides and antibiotics is a growing global crisis.
• The concept of shared resources, like treatment susceptibility, is often overlooked in resistance management.
• Common waterhemp (Amaranthus tuberculatus) and its glyphosate resistance were modeled to study landscape-scale management.

Purpose of the Study:

• To investigate the impact of spatial scale on herbicide resistance evolution.
• To compare the effectiveness of different herbicide management strategies at various scales.
• To understand how aggregating management practices influences glyphosate resistance in Amaranthus tuberculatus.

Main Methods:

• Developed a discrete-time, landscape-scale simulation model.
• Modeled the evolution of glyphosate resistance in common waterhemp (Amaranthus tuberculatus).
• Assessed the effects of aggregating management strategies at farm and larger cooperative scales.

Main Results:

• Farm-scale, high-efficacy strategies alone did not slow resistance evolution in Amaranthus tuberculatus.
• Aggregating best management practices at large spatial scales hindered resistance evolution.
• Aggregating poor management practices exacerbated resistance; tank mixtures were more effective than rotations.

Conclusions:

• Landscape-scale cooperative management is essential for addressing shared-resource resistance problems in weeds.
• Effective weed resistance management requires coordinated strategies beyond individual farm boundaries.
• The findings have implications for managing resistance in analogous pest and pathogen systems.