Pacific Pests, Pathogens and Weeds

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Summary

• 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.