Hmmm.. I have seen SINGLE Kola Plants in person before. They had just the main stalk, not one other branch and one big COLA. It was called Lolly-Popping. Can not remember everything he said on how to do it. But he flowered early, and clipped all the branches off when they got about one inch long, but not to close to the main stock. It looked cool as hell. About 25 nice big COLA sticking up all over the place with no branches and little shit branches. I thought hard about giving it a try. But I was afraid I would screw it up and get shit for a yield.
As for keeping plants close together so the grow taller. Hmmm. does not seem like a good idea. Any branch that is not getting light is energy that is wasted, you might as well clip that branch off. I now get the same amount of buds from 4 plants as I used to with 8 plants, in the same amount of time, and with way less work at harvest time. I would love to have a room full of single cola plants, Harvest time would be so dam easy.
I do not have single cola plants, but when I go into flowering stage, I clip off all the lower branch that the top of is not at least half way to the top of the plant, then I position the plants so that ALL of the branches get plenty of light, I also thin out the BullShit small branches and crap, inside the plant, to allow light in there where the strong branches are. If i made Bubble hash, honey oil or canna butter, I would let the lower branches alone, But i only want the nice big juicey buds. I even have the Bubble bags, and Honey Oil Extractor. I only use the extractor now, and that is not very often.
This is just one of many ways to grow weed. To each his own. Now everyone sit the fuck down and smoke a big fatty.