Effect of fungicides in vitro and on detached berries on control of coffee berry anthracnose caused by Colletotrichum acutatum and C. gloeosporioides
M.K. KennyA, V.J. GaleaB and T.V. PriceC
A Coffee Industry Corporation Ltd, PO Box 470, Ukarumpa, EHP 444, Papua New Guinea.
B School of Agriculture and Food Sciences, The University of Queensland, Gatton Campus, Gatton, Queensland 4343 Australia.
C Department of Agricultural Sciences, La Trobe University, Bundoora, Victoria 3086, Australia.
Summary
Potential fungicides for the control of coffee berry anthracnose in Papua New Guinea were identified. Sixteen fungicides were tested in vitro at 100 µg mL-1 a.i. for their inhibition of spore germination and mycelial growth of Colletotrichum acutatum Simmonds and C. gloeosporioides (Penz.) Penz. & Sacc. isolates from anthracnose infected coffee berries in Papua New Guinea.
The most effective fungicides (triademorph, captan, thiram, propiconazole and copper oxychloride) were tested further at concentrations between 0–12800 mg L-1 a.i. Thiram at 200 µg mL-1 a.i. was the most effective fungicide followed by propiconazole. Detached coffee berries were not infected by C. acutatum and C. gloeosporioides when treated with suspensions of the five fungicides at the in vitro rates that totally inhibited spore germination and mycelial growth. The results showed that thiram at 200 µg mL-1 a.i. and propiconazole are the best fungicides for field testing of control of anthracnose on coffee in Papua New Guinea.
Keywords: fungicide control; spore germination; mycelial growth.
Plant Protection Quarterly (2012) 27 (2) 59-63.