Use of Wood Fibre Compost for the Cultivation of Trichoderma sp. (Isolate Td22)

Abstract: The main objective of this research was to investigate the ability of a Trichoderma sp. (Td22), inhibitory to Sclerotinia minor Jagger, to grow and survive in mature wood fibre waste (WFW) compost of paper mill origin following nutrient amendment. The growth and survival of the fungus in the WFW compost was assessed by serial dilution plate count method followed by confirmation of the fungal identity using pectic enzyme analysis as described in Cruickshank and Pitt [1]. It was found in this study that the population densities of Td22 achieved under non-sterile conditions in the WFW compost following nutrient amendment was approximately in the range of 7.0 log10 CFU/g dw – 8.5 log10 CFU/g dw after 28 days, depending on pre-treatment. The efficacy of this WFW compost-grown Td22 for protection of lettuce from attack by S. minor was also demonstrated in glasshouse trials. This study indicates that cellulosic paper mill waste compost could provide an abundant low-cost growth medium for the large-scale cultivation of fungal antagonists, improving prospects for cost-competitiveness with chemical treatments. Key words: Compost, biological control, Trichoderma sp., Sclerotinia minor.