Meloidogyne arenaria Populations on Soybean

Area of Science:

• Plant Nematology
• Agronomy
• Soil Science

Background:

• Root-knot nematodes (Meloidogyne spp.) are significant soybean pests.
• Previous surveys indicated their presence in South Carolina, but detailed distribution and specific races were not fully characterized.

Purpose of the Study:

• To determine the distribution of Meloidogyne spp. in South Carolina soybean fields.
• To characterize Meloidogyne arenaria populations, including host race designation.
• To evaluate the impact of Meloidogyne arenaria on soybean growth, yield, and reproduction under different soil conditions.

Main Methods:

• Field surveys were conducted across soybean production areas in South Carolina.
• Nematode species identification and population assessment.
• Greenhouse and field microplot experiments using soybean cultivars with varying host suitability to M. arenaria.
• Assessment of root galling, plant growth parameters, seed yield, and nematode reproduction.

Main Results:

• Meloidogyne arenaria, M. incognita, and M. javanica were identified in six of seven surveyed counties.
• M. arenaria populations were designated as Host Race 2 due to lack of reproduction on 'Florunner' peanut.
• Soybean growth was more influenced by soil factors than by M. arenaria populations.
• Differential galling and reproduction rates were observed between two M. arenaria populations.

Conclusions:

• Meloidogyne spp., particularly M. arenaria, are widespread in South Carolina soybean production.
• Soil properties play a critical role in mediating the impact of M. arenaria on soybean.
• Further research is needed to understand the complex interactions between soil, soybean cultivars, and Meloidogyne spp.