Narrow distribution. Southeast Asia, Oceania. Only on yams. There are two types which are very similar. Minor diseases.
The two diseases occur late, and are unlikely to affect tuber yields.
Yellow to light orange pustules on leaves and, for one rust, sometimes on leaf stalks and stems.
Biosecurity: Transfers of yams between countries should be made as plants in tissue culture, preferably tested for viruses. A rust outbreak in Pohnpei, Federated States of Micronesia (2000/2001), may mean severe strains exist.
Cultural control: none recommended for these diseases.
Chemical control: none recommended for these diseases.