Potato tubers may be infected with superficial skin diseases, such as common scab, powdery scab and rhizoctonia. Sweet potatoes may be infected by scurf. The tubers are often edible if the infected areas are cut out. Rotate crops and plant from healthy stock.
White mould or sclerotinia is a fungal disease that can attack most vegetables, especially beans, celery, lettuce and the broccoli family, mainly from spring to autumn. Soft brownish water rots develop mainly on the stems, followed by a fluffy white growth and small black pebble-like bodies. White mould may stay in the soil for many years and affect following crops. Do not over-crowd or over-water plants.
Fungal diseases such as fusarium, rhizoctonia and verticillium can cause wilting and death of most vegetables, by attacking roots and basal stems. Burn diseased plant remains, rotate crops and use new stakes. Some hybrid tomato varieties have resistance to fusarium.