National Grape Research Alliance

08/24/2026

The “devilishly invasive” tree of heaven is the native host to the spotted lanternfly. Virginia Tech forest pathologist Carrie Fearer is leading a multi-institutional team of scientists to find out if Verticillium, a natural fungus that kills tree of heaven could be vectored by SLF. “The ideal scenario is that humans inoculate a tree with the fungus, and the spotted lanternfly picks up the fungus (and) transmits (it) to another tree of heaven,” either by feeding or by spores on the insect’s body. The hypothesis is, by reducing TOH populations, the prevalence of spotted lanternfly also will decline. (Story on p. 13.)

https://vtechworks.lib.vt.edu/server/api/core/bitstreams/77e95660-c16b-4888-ac32-57e804e5ddf0/content

08/21/2026

In this Vineyard Team podcast, Anne Johnson, a postdoctoral researcher/entomologist at Michigan State University, shares new research on spotted lanternfly showing that there are natural “generalist predators” for the invasive pest, predominantly arthropods like spiders and praying mantises. Despite SLF’s bright coloration (nature’s “do not eat” danger signal), the scientific team found that birds will eat the pest, but only if it hasn’t been feeding on its preferred host, tree of heaven. More reason to remove tree of heaven--having birds help manage populations of SLF!

Enjoy interviews with researchers, farmers, and thought leaders in the area of sustainable wine growing.

08/20/2026

Following the July incident in which glassy-winged sharpshooters were found in nursery shipments to Costco locations in California, the Pierce's disease-spreading pests continue to cause concern. While state officials have yet to find GWSS in commercial vineyards, a confirmed find in a nursery in San Luis Obispo county on August 4 turned up the heat. CDFA committed $820,000 in emergency funding to support inspections and trapping for at least three years. California's two U.S. senators, Alex Padilla and Adam Schiff, asked USDA for $32 million in emergency funds to trace and trap the pests, but the request was rejected.

The glassy-winged sharpshooter is spreading across California. State officials are racing to contain the invasive pest before it reaches commercial vineyards.

08/19/2026

Europe’s first incidence of Pierce’s disease was on the Spanish island of Mallorca in 2016. A single infected grapevine in Portugal in 2023 signaled its arrival on the mainland. Historically, European winters were too cold for the pathogen to survive, but researchers now estimate that 41.2% of European vineyards are at climate risk of PD, up from 21.8% in previous models. Scientists fear that “by the time symptoms become obvious, the pathogen may already be established.”

As warming temperatures increase the risk of Pierce’s disease in European vineyards, researchers and growers are looking to California for lessons in detection, prevention…

08/18/2026

Research led by Harlene Hatterman-Valenti and the NDSU Grape Germplasm Enhancement Project led to the official release of a new cold-hardy white winegrape designed for North Dakota’s tough growing conditions. Called Dakota Primus, its bud freezing tolerance is −32.4 °C, it breaks bud later in the season, shows low disease incidence in unsprayed field trials, and offers good wine quality with balanced sugar and acidity, and a citrus-forward profile featuting lemon and apricot notes.

‘Dakota Primus’: A Resilient White Wine Cultivar for Northern United States Agroclimatic Challenges

08/17/2026

Vine netting is no longer used only to protect ripening clusters against hail, birds and other pests. Positioning netting around the fruit zone can temper heat and solar radiation, moderate ripening, and protect acids, anthocyanins and fruit quality in the critical lead-up to harvest. But netting also can alter the berry microclimate and create favorable conditions for disease. Understanding the tradeoffs can help grape growers successfully deploy “one of viticulture’s most versatile climate adaptation tools.”

Netting is no longer just for hail—it is becoming one of viticulture’s most versatile climate adaptation tools…

08/14/2026

Due to ongoing challenges from climate change, invasive pests and more, vineyards increasingly rely on hybrids of V. vinifera and North American species for resistance. Plus, most wine, raisins and table grapes anywhere in the world come from grapevines grafted onto North American rootstocks. But many populations of wild species are disappearing as their natural habitats are lost to highways and houses, and most of the species are poorly represented in botanic gardens and other repositories. We are in serious danger of losing future opportunities to capitalize on these valuable genetic assets. A group of conservationists, including the New York Botanical Garden, seeks to protect and preserve them.

Grapevines have been an area of focus in my research over the last five or so years, involving a tremendous amount of learning and an equivalent increase in appreciation for these wondrous lianas.

08/13/2026

Research led by Jim Harbertson at WSU Viticulture & Enology addresses gaps in many de-alcoholization studies by isolating the influence of alcohol concentration from grape maturity to shape wine aroma and sensory perception. Using Sauvignon Blanc and Cabernet Sauvignon wines, then controlling harvest timing and using both pre- and post-fermentation alcohol adjustments, the team found that winemakers may have more flexibility to meet demand for lower alcohol while minimizing the loss of aroma intensity or varietal character.

08/12/2026

UCCE Viticulture Advisor Christopher Chen is studying the effects of mothballing, helping grape growers understand the path to putting vineyards on pause—and bringing them back online. In the first year of his research in Sonoma and Mendocino Counties, he’s made several significant observations: 1) pests come back immediately; 2) the vines don’t appear to be water-stressed as a result of not pruning or managing the canopy; and 3) berry development slows under mothballing conditions—without pruning, there are more shoots and clusters and thus more berries, but they are smaller and with less sugar accumulation.

A UCCE viticulture advisor is studying vineyard “mothballing,” which entails maintaining vines with minimal inputs, while aiming to return to production in the future.

08/11/2026

A UCLA-led study found that, based on satellite observations, land sank as much as three feet in California’s Sacramento Valley from 2020 to 2022 due to increased groundwater pumping and did not rebound after those drought years. The rapid and extensive land subsidence points to a loss of storage capacity in the aquifer system in the region, and could indicate the Central Valley’s water problems could be spreading north. Land has sunk by as much as 30 feet in the San Joaquin Valley farther south.

"We are seeing a practice go from reversible effects to irreversible effects."