Effect of carbon amendment and soil moisture on Tylenchorhynchus spp. and Hoplolaimus galeatus

The effect of amending soil held at 3 different moisture levels with glucos e, unsulfured molasses, or nutrient broth (0.3, 0.7, 3.2, 7.1 g carbon/100 g) on Tylenchorhynchus claytoni and T. dubius was investigated. When soil w as held under saturated or flooded conditions in the absence of carbon amen dments for 7 days, Tylenchorhynchus populations were 19% and 16%, respectiv ely, of the controls. Carbon amendments at all levels tested precipitated a further decline in the nematode population to 1% or less of the unamended controls in 7 days. Two applications of molasses (7.4%, w/w) 3 days apart t o nematode-infested soil held in Conetainers under mist for 7 days reduced Tylenchorhynchus spp and Hoplolaimus galeatus densities to 7% and 3%, respe ctively, of the controls. Nematode densities in turfgrass field plots also declined following irrigation and repeated drenching with a molasses soluti on. Based on the observed decline in redox potential and pH in saturated so il, especially following carbon amendment, we propose that the activity of anaerobic fermentative bacteria was responsible for the reduction in nemato de densities.