Sustainable pest management for Alfalfa mosaic virus in chile peppers in organic and conventional production

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Commodities

• Vegetables: peppers

Practices

• Education and Training: demonstration, extension, farmer to farmer, on-farm/ranch research
• Pest Management: biological control, integrated pest management, prevention
• Production Systems: organic agriculture

The recent discovery of alfalfa mosaic virus (AMV) (Martellivirales: Bromoviridae) in the southern region of Colorado has caused significant losses for chile pepper farmers. Before AMV was identified in chile peppers, the producers used relatively few chemical inputs to manage pests associated with this crop. However, the virus has resulted in sharp declines in yield and quality of the peppers. AMV is a non-persistently transmitted virus and is spread by aphids that probe peppers but do not need to feed on the plants to transmit it. This mode of transmission eliminates pesticides as an effective means of reducing disease through suppression of the vector. Therefore, our goal is to test the effectiveness of several varieties of peppers with putative resistance to the virus in organic and conventional fields, explore the consumptive and non-consumptive effects of predators of aphids (Hemiptera: Aphididae) that transmit AMV, and examine the synergistic interactions between these two Integrated Pest Management (IPM) approaches. Non-consumptive effects occur when the presence and mere threat of a natural enemy causes defensive, avoidant behavior in prey species. These effects can indirectly affect virus transmission by interrupting aphid settling on pepper plants. This integrative, on-farm project will advance sustainable agriculture by exploiting already available sources of host plant resistance and ecosystem services provided by predators, thereby testing the effectiveness of non-chemical tactics to suppress AMV. This work will involve chile pepper producers, whose fields will be used in the research. This will facilitate seamless dissemination of the research findings and peer-to-peer education. Outcomes and management recommendations will be presented through field days, which will also serve as an opportunity to assess producers’ needs and change in their practices. The research will also be shared at professional conferences, through digital factsheets, and peer-reviewed literature.

Research and educational objectives:

• • Investigate the effect of host plant resistance and consumptive and non-consumptive effects of predators on lowering AMV incidence and severity in organic and conventional fields of Chile peppers 
  • Develop outreach and education programming to increase awareness of best management practices for AMV in chile peppers