Miranda Purcell, Purdue’s viticulture extension specialist and member of the Purdue Wine Grape team, explained that rapid temperature extremes such as seasonally late or early frosts pose the biggest challenge for grape growers in Indiana.
“The cold snap we had the week before Mother’s Day killed green tissue on some of the early ripening grape varieties, especially in the northern part of the state. We saw some damage to the primary buds, which is why you may see some extra growth on vines. Thankfully we are still expecting high yields,” said Purcell.
Many growers reported sightings of the winged form of grape phylloxera, which produces leaf galls or wart-like structures where the female insect lays eggs. Phylloxera is also known to cause detrimental effects to grapevine roots. However, most Indiana growers grow American varieties or French American hybrids that are tolerant to the root gall form of the insect.
Early in the season, Purcell warned growers of the potential for Brood X cicada grape damage. Overall, Brood X did not negatively affect this year’s harvest.
“The biggest news of the 2021 growing season is the detection of the spotted lanternfly in Indiana at the end of July. This invasive insect has almost devastated the entire Pennsylvania wine grape industry,” said Purcell. “The spotted lanternfly lays eggs on anything it can, making it hard to control. We don’t expect to see widespread effects in Indiana for two to three years, but our team and others at Purdue are monitoring the situation for wine grape growers across the state.”
Indiana’s wine grape industry produces over one million gallons of wine each year with 116 wineries and tasting rooms throughout the state. The Purdue Wine Grape team assists Indiana commercial and amateur grape growers and winemakers.
