Soybean Response to Two Isolates of Meloidogyne arenaria.

Meloidogyne arenaria (Neal) Chitwood and M. incognita (Kofoid and White) Chitwood, prevalent in the sandy soils o f the southeastern United States, can severely limit soybean, Glycine max (L.) Merr., yield (10,12). Meloidogyne arenaria populations have increased in some southeastern states in recent years, apparently due to increased plantings of the soybean cultivar 'Centennial', which is resistant to M. incognita but susceptible to M. arenaria (5). The planting of M. incognita-resistant tobacco cultivars has also caused an increase in M. arenaria populations in South Carolina (2). Also, removal of the fumigant nematicides DBCP and EDB, which were more effective than other nematicides against M. arenaria (1), may have resulted in increasing M. arenaria populations. Meloidogyne arenaria is more damaging to soybeans than M. incognita because of the reproductive capabilities of the nematodes (7,10). Physiological races within a Meloidogyne sp. may complicate breeding of resistant cultivars. Because some evidence exists for differences in nematode viru-