Evaluating Trichoderma atroviride and water supply impacts on Miscanthus x giganteus in New Zealand

Abstract

Miscanthus x giganteus is one of the most promising biofuel feedstocks in the world. This second-generation biofuel source yields 40+ t DM/ha/yr without the need for high inputs of synthetic nitrogen fertiliser. In New Zealand, M. x giganteus is primarily used for the replacement of tree shelterbelts removed for centre pivot irrigation. The perennial, hybrid grass provides at least 16 ecosystem services to a landscape and therefore enhancing its production potential is desired. Trichoderma atroviride is a soil fungus that often functions as a bio-control agent against soil-borne plant pathogens and as a plant growth promoter. Past research indicates that there is potential to use this fungus to enhance plant production. The objective of this glasshouse study was to evaluate whether T. atroviride increases M. x giganteus production and some physiological parameters under varied water conditions: Drought, intermediate to well-watered. Results concluded that water significantly increased all plant variables, which was expected. Well-watered M. x giganteus plants had a mean dry weight of 60.4 g plant-1, producing 238.7% and 756.0% more dry matter than intermediate and drought plants respectively. In contrast, the PR5 T. atroviride strain mix had no effect on any variable compared with plants that were not inoculated. However, there was an interaction between T. atroviride and water in inoculated plants under drought. Inoculated drought plants had a 21.0% higher chlorophyll content and 3.6% higher percentage of total dry matter than plants that were not inoculated. Further research in the field is required to determine the effects of variable soil fertility treatments on M. x giganteus plants with and without T. atroviride. Monitoring the abundance of T. atroviride in roots of M. x giganteus under variable water treatments would also be valuable in determining the competitiveness, effectiveness, growth and survival of the fungus in certain environments.