Wikipedia:Reference desk/Archives/Science/2022 June 7

= June 7 =

Is it known by what percentage does the vineyard yield increase if pruning it?
Is it known by what percentage does the vineyard yield increase if pruning it? I have heard it increases it, but I am not sure if it is a myth or supported by science. If it is scientifically approved, then what's the explanation behind it? --ThePupil (talk) 17:49, 7 June 2022 (UTC)
 * Hi, . UC Davis have likely published data on that. Bottom line you're going to lose yield due to pest and disease if you don't spur prune at the start of the season, and likewise canopy management during the season is also important for those reasons and more. Grape vines are a lot like a plumbing system, if you got a double cordon with 6-8 spurs on each cordon then you're going to have an efficient transport of water and nutrients and a predictable (that's very important) yield. If you're letting a grape vine ramble you're creating ideal conditions (lack of airflow, less sunshine and more damp) for pests and disease (powdery, vine mealybug etc) and there won't be much of a basis for working out whether your yield is correct. Plus the rootstock might start to take over. Best to stay on top of it. You might find the 'umbrella canopy' system useful to protect from the increasing summer temperatures. Regards, Zindor (talk) 18:40, 7 June 2022 (UTC)
 * (Not the OP) Are you saying that it's not that the yield increases per se, it's that the yield per input (water, fertilizer, pesticide, etc.) gets better since the rambling bits are less efficient uses? 64.235.97.146 (talk) 19:47, 7 June 2022 (UTC)
 * In a rambling vine, because of the competition for nutrients and water, the fruit set would predictably be lower: there would be imbalanced cluster sizes and weights and in some clusters a lack of usable berries. With a trained vine you'll have a decent amount of inflorescences that set, a lack of useless bull shoots and suckers, and the resulting fruit quality will be high. Quality control for flavour is important in winemaking, so there needs to be the correct concentration of minerals, water, sugar and acids. Without even taking into account pest and disease, the actual yield (regarding area) will be higher. Additional costs are important too but the kind of problems not pruning would bring wouldn't be able to be solved with excessive fertiliser or pesticides. Regarding harvesting too, without a trellising system the machines will not be able to harvest the grapes, and with all the rambling vines even people hand-picking would find it abysmally difficult (grape vines attach themselves to each other with strong tendrils, making an impassable tangle). Hell, the snakes would be having a great time though! Zindor (talk) 21:06, 7 June 2022 (UTC)
 * Interesting - thank you! 64.235.97.146 (talk) 14:53, 9 June 2022 (UTC)