Development of a Trichoderma atroviride based bio-inoculant for New Zealand's pastures

Abstract

New Zealand's pasture production is dominated by two species, perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.). The quality pastures they deliver are the key to New Zealand's NZ$22B pastoral production industries. However, New Zealand's pasture soils contain a diverse range of soil-borne pathogens that impact pasture yields. While controlling them remains a challenge, biological control may offer a solution. Following in-vitro and glass-house screening of Trichoderma isolates belonging to diverse species, a prototype pasture bio-inoculant (BPI) was developed from a mixture of four T. atroviride isolates. Field experiments over several seasons have produced variable responses to the PBI, ranging from nil in pastures grown in non-stress environments to highly significant increases in seedling emergence, plant persistence and dry matter production in pastures challenged by soil-borne pathogens and/or abiotic stress. Reasons for these results are discussed.