In the final weeks before harvest, wine producers face a race on two fronts. Each additional day on the vine improves grape ripening, increasing sugar and aromas, but also raises the risk of losing the clusters. The first warning signs appear when brownish and withered berries emerge within an apparently healthy cluster.
September places any producer before the same difficult decision. The grapes have not yet reached their ideal point, but rain is forecast, and from that moment on, time is no longer on their side. It is the classic harvest race: wait to gain quality or harvest before everything is lost.
The culprit behind this situation is a fungus that is always present in the vineyard, hidden in pruning debris, old leaves, and damaged berries. During summer, the fungus remains discreet because it lacks humidity, and rain is the element that releases it and allows its spread.
Gray rot attacks the clusters in the final stage of ripening, covering them with a grayish-brown mold. Unlike other diseases, this fungus does not need to infect the plant through wounds, making it particularly dangerous during the critical period preceding harvest.
