It is that time of year - time to prune the vineyard. For us this year, we will be using a mechanical prepruner.
What, you might ask is a mechanical prepruner and why do we want to use it? It is a hydraulically controlled machine, pulled behind a tractor with computer assisted cutting blades. The spinning blades are actually stacks of blades which can be easily moved about the vine cordon and the bottom blades cut the spurs to the desired length. The rest of the blade stack shreds the old vine structure leaving behind twigs and sticks which will easily decompose over the summer. This saves quite a bit of time and is well worth the rental.
Here is a close up of the blade stack. If you zoom in, you might make out the warning label about not loosing fingers and hands!
As the tractor pulls the prepruner down the row at 1.4 miles per hour, the two sets of opposing blades do their work on two vine rows at a time. Someone (our oldest son in this case) sits on the prepruner watching and adjusting as it goes. For our vineyard, we want to leave about 4 inches of spurs coming out from the cordon.
From the rear, the operator has a good view of the vines. There are seats for two people - one to operate each arm. Two people are needed when a vineyard is not uniform in growth or the ground is uneven.
Since our son competently controls both arms, the second seat is vacant. But not for long, since there is a long line of eager children ready to help watch.