In Sarawak, Acacia mangium seedlings were inoculated with 50 different Trichoderma isolates obtained from a wide variety of healthy plants in the Planted Forest Zone. The best Trichoderma isolates were selected after 10 trials at the Samarakan Nursery between August 2008 and August 2009. Trichoderma inoculation increased seed germination and seedling establishment (by up to 36%), seedling height and stem diameter (by an average of 25%) and the proportion of healthy seedlings meeting specifications for planting out into the forest by an average of 41 %), compared with untreated controls. Seedlings that received multiple fungicide sprays (standard nursery practice) generally performed slightly less well than the untreated controls. A new Trichoderma inoculum production facility has been built at Samarakan Nursery and Trichoderma inoculation of seedlings will replace the use of fungicide sprays. The economic benefit from increased productivity is estimated to be NZ $2.5 million per year.