Hi, Can't find this information anywhere. I have five 6 year old Himrod Seedless growing on an arbour. Lots of grapes. But also huge amount of greenery, growing down to the ground. Major tangles on the top. Arbour about 6' by 5'. Can I cut leaves away from over the bunches? Do I need to limit the length of the vines? The plants have been properly pruned in the winter by traditional, 2 bud per branch, methods. South facing, terraced property, West Vancouver. Thanks
This is known as "canopy management". A six year old vine can be considered mature in it's root system development, and should be able to support a full crop load. The question is: how much is that? It depends on vine variety, spacing, soil type, the weather (great so far), water, competition from ground covers and nearby plants... Take stab at an approximate yield: let's say 3 tonnes per acre, vine spacing of 10 feet by 10 feet suggests 15lbs per vine, though it could be half that on a 6 x 5 arbor. Look for 20 leaves per bunch. That takes care of crop load and photosynthesis to support it. Other factors: berries like to have some direct sunshine, thin to achieve this. Shading reduces the leaf's ability to synthesize nutrients, so if more removals are required, try to remove shaded leaves. A dense canopy is more susceptable to fungi and molds: increase air flow if possible. Record what you do this year so you can modify it next year. Ralph
Thanks for your reply. In my case, it's "canopy mismanagement." You suggested 20 leaves per bunch. Is that 20 leaves on the stem bearing the bunch or is it 20 leaves on the plant as a whole? This may end up becoming an academic question as all my grapes were eaten last year by the critters. Still...hope springs eternal.
Usually 15 to 20 leaves on the same stem as the bunch, but commercial "trimming" is often done by machine so there must be some tolerance for variation. Ralph
Thanks So if I keep the stems with the grapes, plus some robust new stems for next year, can I cut a lot of the rest of the foliage without hurting the plant or is it even necessary? Will it have any effect on grtape quality one way or the other?
