You are not the only one who has this concern. Read the first page if you want to see others express the same concern before you have here.
-Meeks
I think it is an interesting speculation that a smaller root mass may produce equal flower yields. In all sorts of food crops, plants or trees are deliberately stressed to fruit more heavily. However, i tend to think more unrestricted growth, less stress will more likely produce more biomass, but not perhaps as much thc or some other wanted result. One way to conduct this experiment in hydro is too simply simply a small and large container and weigh the root mass after harvest as well as flower yield, If using some kind of media, one must record the original volume and oven dry weight of the soil before and after the experiment. If there are a lot of organics in the media, some may oxidize and some media may settle or collapse during the grow, bur useful info can be gleaned. For instance a larger pot may have a lot of roots at the bottom but the roots in the smaller pot may be forced to exhaust all the media volume so while the smaller pot may appear to have less roots, it may have a more fibrous and packed (rootbound mass). Only way to tell, is to weigh the root biomass at harvest and subtract weight of original media in each pot.
Example If large pot 5 gallon bucket holds 5 times as much volume and logically 5 times the soil weight, of a true 1 gallon bucket. For the best comparison both the buckets need to be the same height or the shorter pot or bucket will always have less airspace. Take a kitchen sponge. hold suspended flat and let water drain, then turn short side up and more water will drain...then stand in tallest orientation and even more water will drain. In all case same sponge which held as much water against gravity in each orientation. Say we fill with coir which a 5 kilo block 11 pounds yields about 2 to 2.25 cubic feet or 15 to 17 gallons or .64 to .73 pounds per gallon or 10.24 oz to 12 oz per gallon dry. 5 gallon = 3.66 pounds and one gallon pot about .73 or about 12 oz dry coir. Let us say 5 gallon pot yields 1 pound of bud and the 1 gallon pot yields 8 oz, one could reason 16oz bud per = 5 gallon volume soil vs 8 oz bud per 1 gallon soil volume. The smaller pot would yield 40 oz bud for same soil volume vs 16 or 2.5 times bud yield for equal soil volume. However upon weighing the root mass - weight of soil you were to discover the roots in the small pot weighed the same after subtracting soil weight, you could further conclude that yield was actually stunted by constricting the root zone in volume which forced a change in root morphology to a more fibrous root zone equal in root biomass to the larger pot where the roots were never forced to exploit the full root volume. S o is the smaller pot good or bad,,,DEPENDS, IF containers are cheap one might choose to grow 5 xs the number of plants while using only as much soil volume as a 5 gallon grow might use...thus for 2.5 times the bud yield for same soil volume and same root biomass..just less bud per plant. I am just making these numbers up, but i will conduct such a study at some point in 2020 and share the results.
I can almost guarantee, that pruning the roots on a frequent basis will wound the plant and pruning at longer intervals would cause even more shock. One could groe in tight mesh that entraps then constricts and prunes the roots or use a copper hydroxide root pruner such as spinout treated fabric pots to chemically and nearly instantly prune root tips as they contact high copper concentrations to produce a similar effect
