Clubroot of crucifers are favoured by soil pH

Clubroot of crucifers is favoured by soil pH 5.7.
Clubroot of Crucifers is a fungal disease that affects several plants in the cabbage family including cabbages, radishes, mustard and ornamentals such as candytuft.
It is caused by the fungus Plasmodiophora brassicae and gets its name from the club-like roots it induces in infected plants.
Warm soil (20° - 24°C), high soil moisture and acid soil (pH less than 6.5) are environmental factors that favour infection and severe disease development.