- Distribution: Hawaiian Islands – Hawaii, Maui, Oahu, Kauai, Molokai, and Lanai. However, it only infects trees in a few locations on each island.
- Damage: Small leaves with powdery cinnamon to dark chocolate rust pustules on top and bottom leaf surfaces; brown, necrotic leaf spots; leaf curling and yellowing; leaf death, premature defoliation, tree decline
1) Good sanitation – pick up fallen leaves, prune to remove severely diseased leaves
2) Improve aeration in crowns by controlling weeds, removing windbreaks, and pruning
3) Do not plant tree heliotrope side-by-side. Intersperse with other species.
4) Avoid transplanting rust-infected seedlings
5) Do not introduce infected material into a rust-free area
6) Plant at sites with lower humidity/rainfall
Source: Rust of Tree Heliotrope, by Scot Nelson. University of Hawai’i at Manoa, College of Tropical Agriculture and Human Resources, Plant Disease PD-88, June 2012.