By Blake Jackson
A new computer model developed by Cornell University can help grape growers estimate potential freeze damage to their crops. This is crucial as climate change disrupts traditional weather patterns, leading to shorter winters and earlier bud break in vines. Early bud break exposes grapes to spring cold snaps and frosts that can significantly impact yields.
The publicly available model allows Northeast growers to select their location and grape variety. By incorporating data from thousands of weather stations, the model predicts within a few degrees Fahrenheit whether the buds have likely suffered freeze damage.
"If a freeze event occurs and surpasses a cultivar's tolerance, the buds die, affecting the harvest because flowers develop within the buds," explains Jason Londo, a Cornell professor involved in the project.
The model accounts for the varying cold hardiness of different grape cultivars. This hardiness follows a U-shaped curve throughout winter. Each cultivar is most tolerant to cold in mid-winter, with lower tolerance at the beginning and end of the season.
While hardier cultivars like Cayuga White can withstand temperatures as low as -20°F in mid-winter, new growth in spring is highly vulnerable. This green tissue has a higher water content and freezes at around 28-29°F, making vines susceptible to spring frosts.
To develop the model, researchers at Cornell AgriTech have been collecting data on grape cold hardiness for various cultivars since 2009. While this data is specific to their location, the model allows users to input their local weather data and receive a prediction for their area.
"This model might not be as helpful in mild winters like this one," says Londo. "But in the future, if we have a cold snap in March or April, growers can use our website to see if it was cold enough to cause damage."
The model's prediction can inform crucial decisions for growers. If damage is likely, they can evaluate the extent using a razor blade and adjust their pruning practices accordingly. Potentially, this might involve leaving more buds on the vine to compensate for lost yield. In cases of severe damage, growers may need to adjust their plans for the season, potentially seeking crop insurance or sourcing fruit from elsewhere.
The Cornell team is committed to ongoing research. They plan to continue monitoring grape cold hardiness and collaborate with partners across the Northeast to validate the model's accuracy in different regions. Additionally, they are exploring the genetic factors that influence cold hardiness and slower bud break.
"As the climate warms, bud break occurs earlier, but the risk of frost doesn't necessarily decrease," says Londo. "We're aiming to understand the impact of freeze damage on buds and develop new technologies to mitigate these challenges in our increasingly unpredictable climate."
Photo Credit: cornell-university
Categories: New York, Business, Education