One of the major concerns regarding mechanical vineyard pruning is the time and cost associated with replanting a vineyard in a manner that would accommodate the process. However, a report from University of California Cooperative Extension researchers that was published in HortTechnology demonstrates that replanting is not necessary. Research conducted in Madera County found that growers can mechanize their operations by retraining vines without suffering any fruit loss or decline in quality.
“The trial actually ran for three years,” said Kaan Kurtural, UC Cooperative Extension specialist in the UC Davis Department of Viticulture and Enology. “In the end, there was like no loss in yield even during the conversion years and the quality was actually much better in the mechanically managed plants.”
As AgNet West previously reported, mechanical vineyard pruning is becoming more attractive to growers as machines become more effective and the cost of labor continues to increase. Vineyards pruned mechanically have been shown to reduce labor costs by 90 percent. However, many growers have had reservations about switching to mechanization, as the cost of re-establishing a vineyard in the San Joaquin Valley is approximately $15,600 an acre.
The research project began in 2013 and was conducted on eight acres of Merlot winegrapes, in which the grower participating in the project subsequently converted all 53 acres using the methods established by the research. “The grower control was head-trained, cane prune and then we converted this to a California sprawl, the most common one we see and then we also converted this vineyard to a single high-wire system that can be box pruned easily,” Kurtural noted.
Overall, Kurtural said that the work to retrain the vines to a single high-wire system was not a very lengthy process. The research has prompted significant interest from the industry. “We left all the fruiting organs on the trunk as we were training it, so they did not lose any yields essentially,” said Kurtural. “Other growers are doing it on a much, much larger scale.”
Listen to Kurtural’s interview below.