Stunting early in the season, followed by sudden wilting and collapse of the whole plant in warm weather; splitting the crown reveals reddish-brown necrosis, often starting at the outer edges.
Favorable conditions
•Warm, prolonged wet periods after infected transplanting
•Saturated soil allowing motile zoospores to spread and infect wounds
Management
1Use effective pre-plant soil fumigation to produce clean nursery stock
2Alternate Aliette (fosetyl-Al) and Ridomil Gold (metalaxyl-M) treatments
3Use virtually impermeable mulch film where regulations require reduced fumigant rates
Treatment details
Chemical treatment
Aliette (fosetyl-Al) as a plant dip/spray or Ridomil Gold (metalaxyl-M) as a soil drench, alternated for resistance management.
Cultural management
Effective pre-plant soil fumigation (methyl bromide-chloropicrin or chloropicrin/1,3-D mixtures) and use of certified clean transplants.