Harris dc; Yang Jr; Ridout Ms 1993

• Authors: Harris dc; Yang Jr; Ridout Ms
• Title: The detection and estimation of verticillium-dahliae in naturally infested soil
• Location: Plant pathology (oxford), 42 (2). 1993. 238-250.
• Abstract: the effects of several factors on the estimation of verticillium dahliae in soil by the wet-sieving method were studied. the following factors were important for maximising recovery: the removal of soil particles of < 20 .mu.m size from suspensions before plating; The Medium used for plating; The Amount of sieved soil inoculated to plates; The Length of time of incubating plates; and the method of incubating soil on plates. there was no short-term effect of air-drying soil before analysis. using sodium hexametaphosphate to aid soil dispersion, treating soil suspensions with sodium hypochlorite, or making suspensions from different amounts of soil had no consistent effect on recovery. excessive sample-to-sample variability in the results of some experiments was attributed to non-random distribution of fungus propagules in soil, or to the difficulty of standardizing the sieving part of the analysis, or both. wet-sieving was generally more effective in detecting v. dahliae and gave higher counts than a sucrose-flotation method. bait methods with eggplants (solanum melongena) or Antirrhinums (Antirrhinum majus) proved ineffective for estimating v. dahliae in naturally infested soil.