- Widespread distribution. Asia, Africa, Oceania. On sweetpotato and relatives. Occasionally, an important disease.
- Veins on young leaves show clearly, side shoots grow, becoming bushy, erect, with small leaves.
- Caused by bacteria-like organism in phloem tubes.
- Spread by leafhoppers that feed on diseased plants then infect others after 20 days. More important in dry times. Storage root yields absent or very low.
- Cultural control: plant only disease-free vines; do not plant near infected crops; remove affected plants when seen; collect and burn trash after harvest.
- Chemical control: PDPs: derris, pyrethrum, or chilli; or synthetic pyrethroids.
Pacific Pests, Pathogens, Weeds & Pesticides
Sweetpotato little leaf (055)
Photo 1. The first symptom on a young sweetpotato leaf with little leaf phytoplasma is a "vein-clearing"; the veins are clearly seen, even the small ones.
Photo 2. The vines infected by little leaf phytoplasma appear bushy; leaves are small and there are many small shoots along the vines.
Sweetpotato little leaf, sweetpotato witches' broom
Candidatus Phytoplasma aurantifolia
AUTHORS Helen Tsatsia & Grahame Jackson
Information from Jackson GVH et al. (1984) Sweet potato little leaf. Advisory leaflet 19. South Pacific Commission. Noumea, New Caledonia. (https://lrd.spc.int/index.php?option=com_docman&task=cat_view&gid=276&Itemid=615&limitstart=30).
Produced with support from the Australian Centre for International Agricultural Research under project PC/2010/090: Strengthening integrated crop management research in the Pacific Islands in support of sustainable intensification of high-value crop production, implemented by the University of Queensland and the Secretariat of the Pacific Community.