A vineyard in south-central Chile was surveyed during five growing seasons to analyze the increase over time in the number of plants infected with Grapevine leafroll-associated virus-1, -2 and -3. At the end of the study, GLRaV-3 was found to be the most prevalent virus, with 46% of plants infected by this pathogen. GLRaV-2 infected 13% of plants, and GLRaV-1 infected 12%. Considering all three viruses together, the prevalence of infection increased exponentially from 14% of the plants at the beginning of the study period to 68% at the end. The patterns of the spread of GLRaV-2 and GLRaV-3 were mostly along the rows, whereas the pattern of spread for GLRaV-1 could not be determined. |