Feeder roots become rotted and discolored. Affected crowns show reddish brown discoloration when cut. See Reference 1. No thresholds are available. No varieties are resistant but Section 12.1 Recommended Varieties are more tolerant than older standards.
Vigorous plants are less likely to be affected.
Site selection Grow asparagus in fields that have never grown the crop before. Replace the suspension in the clean tank when it is discolored by soil. Drain crowns, and plant as soon as possible. These are not currently viable management options. 47 Phytophthora spear rot , Phytophthora spp.