The research is possible thanks to a grant from the Pennsylvania Wine Marketing and Research Program. The award begins this year with $60,000 for year 1; the grant will be renewed each year, dependent on progress, for up to three years and $160,000 total.
“We hope to have a thermal and multispectral imaging system that a grower can attach to an all-terrain vehicle, drive through their vineyard, and it will produce a map of live and dead buds that then can be used to guide their pruning practices,” said Justine Vanden Heuvel, the project’s principal investigator and professor of viticulture at Cornell AgriTech.
In the Northeast, cold damage to buds is a major issue for grape growers. Winter and spring warming followed by sudden severe cold can kill buds, as vines lose their cold hardiness after a warming spell. In years with large temperature swings, bud mortality can reach 90%.
“We have to really understand what the mortality level is in different parts of the vineyard to guide the pruning practices, because pruning is one of the viticulturist’s most important roles,” Vanden Heuvel said. “It determines shoot number and then determines the yield as a function of that.”
In order to determine the percentage of dead buds on a vine, growers must manually cut nodes with a razor blade to sample and assess the percentage of bud damage. When they know the proportion of live buds on a vine, they can prune accordingly to get the right number of viable shoots for proper yields and flavorful grapes.
But many growers skip this step, which requires many hours of trained labor. The practice also damages vines. Without an assessment, growers often prune improperly and end up with yields that are either too high or too low; when yields are too high, sugars are low in fruits, making them poor wine grapes; when too low, fruit sales don’t cover the cost of production.
“Our vision is that we want to maximize the profitability for growers, especially for grape growers in New York state,” said co-principal investigator Yu Jiang, assistant research professor of systems engineering and data analytics at Cornell AgriTech; his program is focused on developing systems for digital agriculture.