Comparative effectiveness of several methods of soil disinfestation to control Fusarium wilt of carnation

Several fumigant treatments including methyl bromide and soil steaming reduced inoculum densities of F. oxysporum f.sp. dianthi to undetectable or very low levels, whereas high density up to 230 cfu/g was observed at 0-15 and 15-30 cm depth in untreated plots. Following planting of highly susceptible carnation, disease progress was very rapid in untreated plots. Rates of disease progress were lowest for methyl bromide at standard dosage, and metham-Na treatments, whereas for steam treatment a large increase in disease incidence occurred after the moderate rate observed during the first 3 months after planting. The flower yield in the most effective treatments was increased more than 10 times that of the untreated control during the 18 months of the experiment.