One of the best things about working in the UK’s developing viticulture industry is the willingness among growers to share knowledge and discuss potential issues they have faced out in the vines.
However, as a tight-knit community, when methods or machines don’t work as expected word soon ripples across the nation and fellow growers, heeding advice from their peers, often steer clear.
Putting aside the debacle of shortage of labour, there are numerous jobs in the vineyard which could be completed far more cost-effectively if done by machine. De-leafing is unquestionably one of those tasks, yet, growers have been put off leaf stripping machines in the past due to other vineyards’ misfortunes with substandard technology which has damaged fruit.
“Unlike other de-leafers, the Stockmayer has been designed to be very gentle on the vine,” said David Sayell at Vitifruit Equipment. “It sits at the front of the tractor so you can angle it precisely; there is a magnetic sensing system, which pulls the unit back to prevent damage to the fruit if it is going too far into the canopy; and it plucks, not cuts, leaves out as if by hand.”
Capable of completing around five acres per day (based on a single-sided machine and assuming that the vines have been trimmed and the operator is skilled) the Stockmayer has a remote fan which draws leaves into vertical rotating rollers which pull the foliage, before dropping leaves to the ground.
“The key difference with the Stockmayer is the air flow system,” said David. “Other de-leafers allow foliage to enter the fan and, especially when working in wet conditions, this can clog the fan coupling and impede air flow. Operators then notice a reduction in the machine’s efficiency and are tempted to drive closer to the canopy. This is when grapes can be harmed but the Stockmayer doesn’t allow this to happen.”
To further reduce the risk of fruit damage, David has installed a rotary blade mechanism to the de-leafer to remove problematic lateral branches. Stockmayer has also developed a ‘super fan’ which will be available in the UK next year. It has already been used in a number of German vineyards during this current season and proved a big hit.
Alongside improving air flow and reducing disease pressure, using the de-leafer can help improve targeted berry coverage when spraying and if used a few days before harvest it can also help pickers to easily locate bunches.