Fungal trunk diseases: A problem beyond grapevines?

Authors: GRAMAJE, DAVID - Consejo Superior De Investigaciones Cientificas (CSIC); Baumgartner, Kendra; HALLEEN, FRANCOIS - University Of Stellenbosch; MOSTERT, LIZEL - University Of Stellenbosch; URBEZ-TORRES, JOSE - Agriculture And Agri-Food Canada; ARMENGOL, JOSEP - Polytechnic University Of Valencia (UPV)

Submitted to: Plant Pathology
Publication Type: Research Notes
Publication Acceptance Date: 11/28/2015
Publication Date: 3/4/2016
Citation: Gramaje, D., Baumgartner, K., Halleen, F., Mostert, L., Urbez-Torres, J.R., Armengol, J. In press. Fungal Trunk Diseases: A Problem Beyond Grapevines? Plant Pathology. 65(3): 355–356. DOI: 10.1111/ppa.12486.

Interpretive Summary: Grapevine trunk diseases (GTDs) are caused by a range of genetically unrelated fungi, which occur wherever grapes are grown and are the main diseases limiting vineyard productivity and longevity. GTDs cause untenable economic losses. For example, they are considered a “national crisis” in France, where approx. 12% of vineyards are currently economically non-viable due to these maladies causing losses of about 1 billion euros. Because GTDs are chronic and there is currently no option to eradicate the infections, unproductive vineyards must be replanted, at a worldwide annual cost of 1.132 billion euros. Many vineyards with high GTD incidence were planted in the mid-to-late 1990s, during which wine-grape prices were increasing. Other crops, such as almond, pistachio, and walnut, are now experiencing planting booms. The significance of these and other tree crops is that they host some of the same GTDs pathogens. While researchers fine tune strategies for managing GTDs in grape, the pathogens may spread between vineyards and tree crops, thus endangering the productivity and longevity of orchards and vineyards alike. The production of grapevines and tree crops is different; not all practices for GTD management in grape are feasible in tree crops, especially with dwindling numbers of skilled farm laborers. Tree crop nurseries are struggling to meet the demands of many young plants, for planting new orchards. From our experience with GTDs, a lack of first-quality plants means that low-quality plants are sold, too. Are these plantings doomed to a lifetime of poor productivity? Is the sustainability of the fruit and tree nut industries at risk?

Technical Abstract: Grapevine trunk diseases (GTDs) are caused by a range of taxonomically unrelated fungi, which occur wherever grapes are grown and are the main biotic factor limiting vineyard productivity and longevity. GTDs cause untenable economic losses. For example, they are considered a “national crisis” in France, where approx. 12% of vineyards are currently economically non-viable due to these maladies causing losses of about 1 billion euros. Because GTDs are chronic and there is currently no option to eradicate the infections, unproductive vineyards must be replanted, at a worldwide annual cost of 1.132 billion euros. Many vineyards with high GTD incidence were planted in the mid-to-late 1990s, during which wine-grape prices were increasing. Other crops, such as almond, pistachio, and walnut, are now experiencing planting booms. The significance of these and other tree crops is that they host some of the same GTDs pathogens. While researchers fine tune strategies for managing GTDs in grape, the pathogens may alternate to tree crops, thus endangering the productivity and longevity of orchards and vineyards alike. The production systems are different; not all practices for GTD management in grape are feasible in tree crops, especially with dwindling numbers of skilled farm laborers. Tree crop nurseries are struggling to meet demands for plant material and, from our experience with GTDs, a lack of first-quality plants means that low-quality plants are sold, too. Are these plantings doomed to a lifetime of poor productivity? Is the sustainability of the fruit and tree nut industries at risk?