Drought and disease are a source of pressure on vines, causing yield loss and mortality in vineyards. But these plant stresses do not necessarily act in synergy.
Drought and disease are a source of pressure on vines, causing yield loss and mortality in vineyards. But these plant stresses do not necessarily act in synergy. A research team from INRAE, Bordeaux Sciences Agro, the Université de Bordeaux and the Institut Français de la Vigne et du Vin, recently discovered that drought conditions suppress the appearance of esca leaf symptoms, one of the most common grapevine wood diseases. Their results, published on October 21st in PNAS, are a major breakthrough in the understanding of this disease and the complex interactions between plants, pathogens and climate. The continuation of these studies could lead to better prediction of the onset of esca by analysing the physiological state of the plants and drought data.
Over the past twenty years, a global deterioration has been observed in vineyards. Vine yields and longevity are declining and there is an increase in vine mortality in plots (a production shortfall of 3.4 million hectolitres was estimated across vineyards in France in 2014). It is estimated that dieback due to wood diseases causes the loss of 5% of vineyard surface every year1. For a long time, the only cause put forward was vine wood diseases, among which esca is the most prominent. This disease, for which existing treatments do not provide satisfactory control, is caused by parasitic fungi that penetrate the wood of the vine. These pathogens cause necrosis and characteristic symptoms on the leaves (discoloration and necrotic stripes). To explain the mechanisms of this disease, in recent years scientists have put forward the hypothesis of multiple causes linked to pathogens, climate change, farming practices, etc. To better understand the reasons and the complex mechanism leading to this decline, INRAE scientists have studied the interaction of two major factors in vine dieback: esca and drought.
Read more at: INRAE - National Research Institute for Agriculture, Food and Environment
Monitoring of the appearance of esca symptoms on vine leaves in a controlled environment under different drought conditions. ( Photo Credit: INRAE - Chloe Delmas)
