Effect of tobacco crop disposal methods and soil fumigation on control of root-knot nematode (Meloidogyne javanica) in north-eastern Victoria

Abstract

In field trials with tobacco in north-eastern Victoria the complete removal of stubble was not an economic practice. Though yields were slightly higher than with tobacco stubble hoed-in, control of rootknot nematode (Meloidogyne javanica) in subsequent tobacco crops was no better. Autumn or spring fumigation with ethylene dibromide was equally effective in nematode control. Tetrachlorothiophene progressively reduced root-knot indices in three successive crops but there was a progressive increase where aldicarb was used. Nevertheless, highest yields were obtained with aldicarb due, in part, to control of tobacco yellow dwarf disease and to an unknown cause. In north-eastern Victoria, root-knot nematodes cause lower yield loss than in the Murray Valley. Although soils are heavier, the lower soil temperatures may also account for reduced disease severity.