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

Commodities

Practices

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.