Researchers in California are urging vineyard owners to invest in mechanised pruning systems  to become more competitive, rather than rely on manual labour.

California State University, Bronco Wine Co and manufacturer Oxbo have embarked on a project to test pruning equipment which works on the type of trellis system most commonly found in San Joaquin Valley vineyards - the California T, also known as the California Sprawl.

Assistant professor Kaan Kurtural,who is leading the study, said: "As hand labour is becoming more expensive and scarce in the Central Valley, growers are turning more towards mechanisation to reduce costs and to increase efficiency and sustainability of their wine grape operations."

He added: "If we are to remain competitive in the domestic and international wine market, the adoption of mechanical canopy management needs to increase from its current level of 15% across California."

Last summer was the first season of the four-year project, and results look promising, Kurtural said.

"We saved close to a quarter per vine in costs, and we did not lose anything in yield or quality," he said. At 21 cents per vine, 600 vines per acre, that amounts to $126 per-acre savings using a completely mechanised system."