Rotylenchulus reniformis Management and Vertical Distribution in Summer-Winter Crop Rotations Including Carinata

Area of Science:

• Agricultural Science
• Agronomy
• Nematology

Background:

• Brassica carinata (carinata) is a developing winter biofuel crop in the southeastern U.S.
• Rotylenchulus reniformis (reniform nematode) significantly reduces cotton yields in this region.
• Understanding carinata's role in crop rotations is crucial for managing reniform nematodes.

Purpose of the Study:

• To evaluate the impact of winter crop rotations, including carinata, on reniform nematode populations.
• To assess these effects in combination with various summer crops (corn, cotton, soybean, peanut).
• To analyze nematode abundance at two distinct soil depths (0-30 cm and 30-120 cm).

Main Methods:

• A two-year field study in North Florida examined winter rotations: fallow-carinata, fallow-fallow, and oat-carinata.
• Rotations were combined with corn, cotton, soybean, and peanut annually.
• Soil samples were collected over four years after summer and winter crop harvests.

Main Results:

• Reniform nematode populations were higher in the topsoil (0-30 cm) compared to deeper soil (30-120 cm).
• Cotton cultivation resulted in greater reniform nematode abundance than corn, peanut, or soybean.
• While winter rotations showed no consistent effect, carinata tended to reduce reniform nematode soil populations.

Conclusions:

• Carinata shows potential as a winter crop to help manage reniform nematodes.
• Integrating carinata into crop rotation systems provides an additional strategy for reniform nematode control.
• Carinata production expands winter crop rotation choices for farmers in the southeastern U.S.