The response to stress treatments of potted grapevines inoculated with Eutypa lata and Botryosphaeria lutea, fungi associated with trunk disease.

Current management options for grapevine trunk diseases are focused on ameliorating symptoms once they have occurred. In grapevines and other crops, plant stress has been observed to increase symptom expression for different pathogens, depending on timing and type of stress. This research aimed to establish whether stress to vines at the time of wounding enhances colonisation by fungi associated with trunk disease. Potted plants were wounded and inoculated with two grapevine trunk fungi, Eutypa lata and Botryosphaeria lutea. Stress treatments (leaf removal and girdling) were applied to the vines immediately prior to inoculation. Lesion size at the wound site and infection, confirmed by re-isolation of the pathogen, were measured. In these experiments stress did not induce greater infection incidence or larger lesions at the site of wounding. Some difficulties in using potted plants to simulate responses of mature vines in the field are discussed.