Are Cover Crop Combinations Effective at Managing Plant-parasitic Nematodes in Potato Production?

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Commodities

• Agronomic: potatoes

Practices

• Crop Production: cover crops, crop rotation, fallow
• Pest Management: biofumigation, cultural control

Potato (Solanum tuberosum) is a major commodity in Northeast Florida (NEF), producing up to 66% of United States winter potatoes. Among many pests of potatoes, sting (Belonolaimus longicaudatus) and stubby-root nematodes (Nanidorus minor and Nanidorus obtusus) are important in NEF. A cropping sequence of continuous winter potato followed by summer sorghum-sudan grass (Sorghum x drummondii) cover crop is typical in NEF, but both crops increase sting and stubby-root nematodes. Therefore, chemical nematicide application is the main nematode management tactic in the area. This project focuses on assessing various summer and fall cover crops as an alternative method for managing sting and stubby-root nematodes as well as their effects on and free-living nematodes (beneficial, non-parasitic) in potatoes. We will conduct a field trial where we will plant summer cover crops, sorghum-sudan grass and sunnhemp (Crotolaria juncea), followed by fall cover crops, arugula (Eruca sativa) and caliente mustard (Brassica juncea), before potatoes. We will compare cover crops to weedy fallow with or without the fumigant nematicide 1,3-dichloropropene (1,3-D). We will assess sting, stubby-root, and free-living nematodes regularly during the trial. The field trial is a continuation of work done in 2022/23 that needs to be repeated for validation. Further, we will do repeated greenhouse experiments to assess the host suitability of sting nematodes to different cover crops. These studies will provide potato growers with important information on efficacy of selected summer and fall cover crops for reducing sting and stubby-root nematode damage and maintaining beneficial nematodes.

The overarching goal of this project is to improve sting and stubby-root nematode management in potato production by using effective summer and fall cover crops combinations while minimizing negative impacts on soil populations of free-living nematodes.

The specific objectives of this project are to:

1) Evaluate summer cover crops, fall cover crops, and their combinations in field potato production for:

1. Management of sting and stubby-root nematode populations
2. Influence on potato yield; and
3. Impact on beneficial, free living nematode communities.

2) Test the host suitability of sting nematodes to fall and summer cover crops in greenhouse conditions.