Clubroot
Plants become stunted and wilt during the hottest part of the day even when the soil is moist. Leaves may turn yellow and growth slows significantly. Underground, the roots develop swollen, distorted clubs or galls that prevent the plant from absorbing water and nutrients.
Plants become stunted and wilt during the hottest part of the day even when the soil is moist. Leaves may turn yellow and growth slows significantly. Underground, the roots develop swollen, distorted clubs or galls that prevent the plant from absorbing water and nutrients.
Clubroot is caused by the soil-borne pathogen Plasmodiophora brassicae. It survives in soil for many years and spreads through contaminated soil, infected seedlings, irrigation water, and gardening tools. Acidic, poorly drained soils increase the risk of infection.
There is no cure once plants are infected. Remove and destroy infected plants immediately, including the roots. Do not compost infected material. Improve soil drainage, raise soil pH with agricultural lime if needed, and avoid planting brassicas in contaminated soil for several years.
Use disease-free seedlings, rotate crops for at least 4–7 years, maintain soil pH between 7.0 and 7.2, improve drainage, clean tools after use, and avoid moving contaminated soil to healthy garden beds.