A combination of AI and photography is helping wine makers keep their grapes free of disease.

Botrytis cinerea is a fungus—also known as grey rot—which has spores that pierce and infect wine grapes, causing them to shrivel and sweeten. It can add complexity and longevity to sweet wines, like Sauternes; in these cases it is known as “Noble Rot”.

But it is a problem for producers of dry reds, for example, causing widespread losses of harvest in many …