ABSTRACT
The effect of fresh cauliflower residue amendment alone and with a low dose of metham sodium (MS) combined with soil solarization was investigated for the control of Verticillium wilt of artichoke in two commercial fields under artichoke--cauliflower rotation. Treatments were a factorial combination of three main plots (an unamended control, soil amended with cauliflower residue, and a combination of cauliflower residue and a low dose of MS) and two subplots (application of a plastic cover or uncovered). Inoculum densities of Verticillium dahliae were measured before and after soil treatments as well as disease incidence, symptom severity, and yield. Although soil solarization reduced inoculum of V. dahliae and the incidence of Verticillium wilt of artichoke, no added benefit was obtained when solarization was used with cauliflower residue amendments. In addition to toxic volatile compounds, other mechanisms could be involved in disease suppression because the effects of incorporating cauliflower residue were not enhanced by the plastic covering. The effect of cauliflower residues on populations of V. dahliae microsclerotia in soil was inconsistent, possibly due to varying pretreatment inoculum levels. Treatments with cauliflower residue amendments and low doses of MS maintained low inoculum densities in the fields until the end of the growing season and significantly reduced the percentage of infected plants.
