I do routine walks through the vineyards every few days. Not just because I enjoy walking amongst the vines, which I in fact do enjoy doing, but also to conduct minor management tasks such as dealing with wayward shoots that fell outside the trellis and scanning for any hints of health problems with the vines.
Till this week, the weather has been rather mild. Not to hot and not too wet. The heavy rains and downy mildew pressures from last year were significant, and a few vines were weakened from last year’s infestation. These vines this year are exhibiting some stunted growth and less disease resistance. And on one of those weakened vines this week, I saw powdery mildew on some of its grape clusters. Unlike downy mildew, powdery mildew does not need it to rain to become a problem: only cool humid conditions are necessary. As the name of the disease indicates, this fungus looks like white powder on the plant. Diseased clusters were simply cut off the vine.
So far this year the healthy vines seem to be free of powdery mildew. Which goes enhance the importance of keeping vines healthy this year, as it will always affect not just this year’s but also next year’s vine health, performance, disease resistance and wine quality.