Worldwide in the tropics, on many crops. Important diseases.
Fungi, water moulds (oomycetes) and bacteria cause the rots. They enter corms at harvest when suckers are broken off. The common ones are: (i) Athelia – pink with white border; (ii) Pythium - white crumbly rot; (iii) Phytophthora taro leaf blight - firm brown rot; (iv) Lasiodiplodia - black, spongy, sour-smelling rot; and (v) Erwinia - soft rot.
Cultural control: harvest, remove suckers and soil, and store in (i) leaf-lined soil pit, or (ii) plastic bags or (iii) plastic-lined cardboard boxes, if for markets.
Chemical control: improve storage in plastic bags by first dipping corms in bleach (1% for 1-2 mins).