Diseases
White blister
Identify White blister: symptoms, possible causes, prevention, and practical actions for 5 affected plants. White, pustule-like growths on leaves and stems
Editorial diagnosis
Diagnosis overview
White rust forms white blister-like pustules, especially on brassicas and some leafy crops.
In gardens, White blister can occur on plants including May turnip, Horseradish, Common Purslane, Arugula. In the available profiles, it is linked mainly with Asian greens, Leafy vegetables, Root vegetables.
The recorded risk level is medium. Conditions that favour it include Wet weather or prolonged leaf wetness, Dense planting and poor airflow, Susceptible cultivars. It becomes serious when young leafy crops become unusable.
Compare upper and lower leaf surfaces, the boundary between healthy and damaged tissue, and spread after wet weather. Coatings, spores, or progressive rot support a disease diagnosis.
A common mistake is to identify a disease from one spot alone; weather, spread, and pathogen structures also need to fit.
At a glance
Plants
5
Category
Asian greens, Leafy vegetables, Root vegetables, Salads
Risk
medium
Scientific name
Albugo candida
Typical signs
- White pustules
- Yellowish spots above
- Distorted leaves
Possible confusion
- Growing problem: Growing problems are usually linked to water, light, temperature, or soil and do not show pathogen growth, pustules, or progressive infection patterns.
- Nutrient deficiency: Deficiency patterns are often more regular and follow leaf age or veins. Diseases more often show spots, coatings, rot, wilting, or pathogen structures.
Immediate actions
- Remove affected plant parts
- Improve airflow
- Avoid overhead watering
- Keep tools clean
- Remove heavily infected plant residues
Prevention
- Use suitable spacing
- Follow crop rotation
- Choose robust cultivars
- Keep leaves dry
- Support soil structure and plant vigour