Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Phytophthora leaf blight of Colocasia esculenta in the British Solomon Islands.

Abstract

Leaf blight, caused by P. colocasiae, is the most widespread disease of this crop on the larger volcanic islands. None of the 181 local cvs. tested was immune or highly resistant to the fungus. A small proportion, however, did not show high levels of disease. Cu fungicides as foliar sprays, although giving poor control, resulted in yield increases of up to 25%.<new para>ADDITIONAL ABSTRACT:<new para>In trials in 1970-1, C. esculenta cv. Akolomale Initoa was given weekly sprays of 9 fungicides commencing at 29-63 days after planting up to harvesting at 165 days. Corm yields were 4.47-7.58 t/ha in unsprayed controls and 5.27-9.44 t in plots sprayed with Cu oxychloride. None of the other fungicides increased corm yields.