PESTS AND DISEASES

 
Weeds, pests and diseases


For truffle production there are two considerations for pest and disease control – the host trees and the truffle fungus. For oak and hazelnut trees, the experience of established truffle growers is that these trees are generally disease and pest free. The use of insecticides and fungicides on the trees is avoided unless absolutely necessary as the chemicals may have a detrimental effect on the truffle fungus. However, weed control is important and developing a weed control strategy is considered essential to managing a truffière.A major concern for truffle growers is the contamination of their crop from competing ectomycorrhizal fungi. Many Australian trees including eucalypts, wattles and blackwoods and many introduced trees including willows, poplars and pines host ectomycorrhizal fungi which then colonise the roots of inoculated truffle trees and replace the truffle fungus.  Ectomycorrhizal fungi can also be transported by grazing animals. For this reason it is recommended that plantings are fenced to prevent these animals access to the tree plantings.Common to all truffle growing regions around the world is the presence of truffle rot. In Australia, truffle rot has caused crop losses of up to 50 per cent on some properties. Research suggests that there are several factors contributing to the development of truffle rot: the fungal species Trichothecium crotocinigenum; truffles exposed at the soil surface; and consistently moist soil conditions from frequent irrigation. Suggested techniques to manage truffle rot include managing irrigation for appropriate soil moisture and covering truffles that are forming too close to the surface. Further information on managing truffle rot can be found in the RIRDC publications Identifying the Cause of Rot in Black Truffles and Management Control Options and Identification and management of the agent causing rot in black truffles – Part 2.