I know it's an old thread, but I came across it and felt I could add something for other people wondering the same thing. Wow, so ok, this thread is... very interesting? Went from somewhat helpful to nursery bashing lol. There are four ways to control vigor/ size in a tree: Precocity, spacing, dwarfing rootstocks, and pruning out large branches. You can plant them 2ft apart in the row and 8ft alleys as a spindle if you want, or 20 ft apart as an open vase if you want (hint: the spindle is going to yield more than the vase per acre). The biggest thing to maximizing yields is maximizing bearing surface and light interception per acre. I use dual-leader UFO (upright fruiting offshoot) training for everything now. UFO was originally developed for spur-fruiting species (apples, plums, pears, cherries), but it can be modified to work with tip and year-old-growth bearing species (some apples, peaches, apricots). You just have to space out your uprights more and allow for limited lateral branching. For peaches, I plant trees 8 feet apart in row, with 7ft alleys (I use a TYM 234 tractor). I plant the trees at roughly a 45 degree angle. I allow the uprights on the primary leader to grow (keep terminal bud upright), and select one below the bottom cordon to train as the second leader. I then remove the other buds below the bottom wire. By the end of 1st leaf, you should have both leaders tied to the wire, and mostly filled the space between trees, you've pruned off the pendant shoots, and you should have some fruiting wood for next year. In the winter, tip back the fruit sticks and eliminate damaged/crowded wood. second leaf- limited fruiting possible, focus on establishing your uprights roughly every 10 inches (6 inches for spur bearing species) and finish filling in the space. Eliminate pendant wood, shoots sticking outside of the vertical plane, and any uprights beyond your "permanent" ones in late summer, after any harvest (limited regrowth that way). Next year's fruiting wood is now on the upright shoots. Tip back the fruit sticks and eliminate damaged/crowded fruiting wood. Third Leaf- should definitely get fruit, goal is to get your upright shoots to the top wire (which for a should be roughly 75% of your alley width, IMO). Same kind of pruning as previous years. At some point, your laterals are going to start to grow together, at that point, you need to do renewal pruning in the winter back to a bud near the upright. Once your uprights get to about 1.25x your alley width, head the uprights back to on bud above the top wire (otherwise you'll shade the bottom of the next row). As uprights approach 3/4 to 1 inch diameter at the base, take the largest one every year down to one bud above the leader (unlike apples and cherries, peaches don't regenerate as readily, so you need to give it the best chance). All renewal type pruning should be done before budbreak, to encourage vigorous regrowth.

Weeper: Like you I found a lot of conflicting information out there. I eventually stumbled across Prof. Tom Zabadal's youtube chanel. In a nutshell, he has taken a lot of his lectures aimed at commerical growers and posted them online. There is a lot of info, far more than most will want but better too much than too little. It is all based on a long career of field work in viniculture dating back to the early 70's and is very practical vs pure academia. All trainign methods are covered from the most common to obscure with pro's and con's for each system. Some 34 videos in all and still adding regularly. Guyot can be found here https://www.youtube.com/watch?v=eO_zyG5BGTg but if considering that you may want to look at umbtrella kniffen which should be more productive. He will also explain why. Trying to push the zone? in that case perhaps fan training is for you. Some of the later videos on pruning for winter injury are helpful in assuring that the training method and style of pruning do not promote winter die back. All in all I found a lot of info made available thru this channel. Its a bit like taking a course but you can skip thru the sections that are not applicable to what you want to do or learn. 34 videos and counting all posted here: https://www.youtube.com/channel/UCZ7llYhkcOS5eBIS9nMy4LA . Cheers, Dave

Which branch would be the best to bring upright? Two are quite long (5-7 feet) with good size diameters but also likely to break. One is shorter (3') and bends easily. There are several others in the same categories. Once I bring one upright I assume I should cut it off at the top of the pole/where I want side branches? I will also cut off all other branches. Thanks! Ginny

What type of grapes are they? Table vs wine. Seeded vs seedless. Do you know if they are particularly vigorous? How much space do you have for them to grow? I am no expert but in general you want good sun exposure, enough leaf area to ripen the quantity of grapes you want to bear, enough space to avoid crowding and good airflow to prevent fungus/disease. So it depends on your rain/humidity, solar exposure and wind exposure situation is like. If you are growing table grapes of a vigorous variety the Geneva Double Curtain could be very interesting. For the same horizontal space you have 2x the vine length but it will take up more width. It will also bring your vines 6' off the ground and away from the fence which would give more solar exposure and better airflow. But honestly, try whatever you want, if you don't like it cut back to the trunk during winter and start over, you are only 2 years behind. Build the structure this year and get grapes next year. Have fun, other than diseases grapes are super easy. Do some research on bagging grapes with Ziploc and organza bags to help with fungus/insects/birds.