Dry rot – Fusarium spp

Symptoms   Skin shrinks, developing characteristic concentric wrinkles.  White, pink or blue-green pustules break through the infected skin,  Internal cavities lined with fluffy mycelium develop.  Boundary between healthy and diseased areas indistinct.  Tuber infection occurs at wound sites.

Sources and Factors Favouring Development

Seed and soil borne inoculum enters wounds made during harvesting and/or grading.  High temperatures and humidities increase the speed of development of Dry rot once infection has occurred.  Susceptibility increases during the later stages of storage.  Delayed planting or poor soil conditions can result in reduced emergence even where seed tubers show few symptoms.

Control          Select healthy seed stocks and minimise the potential for damage to tubers at harvest.  Dry curing and early treatment of seed tubers with an approved fungicide before wound healing, can give effective control. Planting into sufficiently moist soils will help promote quick emergence and good wound healing.