Koa wilt They are a dominant forest species. Koa wilt has been found on the islands of Kauaʻi, Oʻahu, Maui, and Hawaiʻi. Most diseased trees are found at elevations below 3,000 feet. However, it has also been observed at elevations as high as 7,000 feet. Fusarium, the primary cause of Koa wilt, May be found in a variety of environments but thrives with the high temperatures and moist soils of Hawaii. It survives in the soil. "F. oxysporum" is a soil-borne pathogen, and currently sanitation, controlling the initial inoculum, is the best means to control it. One should avoid bringing infected soil
Acacia koa used by ancient Hawaiians to build "waa" (dugout outrigger canoes) and "papa hee nalu" (surfboards). Only "paipo" (bodyboards), "kikoo", and "alaia" surfboards were made from koa, however; "olo", the longest surfboards, were made from the lighter and more buoyant "wiliwili" ("Erythrina sandwicensis"). The reddish wood is very similar in strength and weight to that of Black Walnut ("Juglans nigra"), with a specific gravity of 0.55, and is sought for use in wood carving and furniture. Koa is also a tonewood, often used in the construction of ukuleles, acoustic guitars, and Weissenborn-style Hawaiian steel guitars. B.C. Rich used koa on some