On a per square foot of soil basis, which one would you say is the best producer?
I like haskaps as much as the next man but a bush needs about 4x4 to produce around 10 pounds of berries, or .625 pounds per square feet. A romance bush cherry needs a bit more space, perhaps 5x5, but if allowed to grow tall it can produce upwards of 30 pounds, or 1.2 pounds per square foot. I don’t know how much a saskatoon bush produces but they are quite prolific.
On a per pound basis, what gives the most?
That’s tough to answer because productivity varies with variety and usually the more productive a variety the more bland the fruit.
From my limited experience I would say my blueberries and currants are usually the most “loaded”. Raspberries, blackberries are just normal and gooseberries are a bit on the low side. I guess it really comes down to how upright growing the bush is when it comes to fruit / sqft.
In the end though the productivity only matters as much as you can protect the berries from the birds! 
EDIT: Do figs count as bushes? I would say they win the prize for value / sqft when grocery store figs are $1 each.
Look for things that are in the grocery store as the most productive. The reason certain fruit is sold at the grocery store is because the produces a lot per square yard and the food saves easier. A good example of something that produces a lot but does not save is the mulberry. A dwarf Girardi mulberry will only get 6 feet but will have berries loaded on every part of the branch. Issue is the berries do not save. Something like the dwarf peaches will be loaded per square foot. People actually have to thin the peaches on the dwarf peaches because they produce so much.
You should try frozen mulberries!
I know, this is mostly a shooting the breeze sort of discussion. Obviously other factors come into play such as value (half as productive vs. twice as expensive) rarity (is not like I can buy them at the store) and of course if you don’t like them well that’s that.
A quick look a the number of pounds per acre typically produced by various crops can provide some insight, but these yields can vary a lot from region to region.
High Density Apples - 30,000 -40,000 pounds
Open Center Peaches -12,000- 18,000 pounds about 2X for dwarf peaches in California
Blackberry -15,000 pounds
Blueberry -8,0000 pounds
Looks like high density apples or perhaps dwarf peach trees produce the most fruit per square foot
Interesting that blackberries are so productive compared to blueberries and yet they are so much more expensive in the grocery store.
I was thinking more of bushes in a backyard setting. Heck trees on most high density apple orchards look more like grape vines than trees, not your typical home setup.
Not to mention that with 43560 square feet to an acre the yield is .69 to .92 pounds per square feet. I’m pretty sure that sacrifices some yield in order to make labor cost effective; a fully producing tree in a 10x10 area could probably pump out 250 pounds of apples, or 2.5 pounds per square feet. You would have to put a lot more labor into harvesting that crop.
I believe blackberries are more expensive because they are more perishable than Blueberries. Also the growth in new acres of Blueberries planted over the past 10 years has been extremely high, much higher than Blackberries. We grow both and our yields are in line with the numbers I posted.
I completely agree that high density apples resemble a vineyard. I thought the first large high density orchard I ever saw was grapes until I stopped by the side of the road an took a closer look.
Even in a backyard setting it necessary to have some space between the rows in order to mow, spray and harvest so you can’t have 100% productive space. If the tree canopy consumes 10 feet X 10 feet how far apart are the rows between the trees? A yield of 2.5#/square foot would be more than 100K pounds per/acre. To the best of my knowledge even super high density apple orchards at 3,000 trees or more per acre growing in the best areas are not close to 100K #/acre.
I did not mention Strawberries, but I have seen yield estimates of over 50K #/acre but you still need to have some unproductive space between to rows so you can not achieve a real yield of 2.5 pounds per square foot.
A single determinate tomato that occupies 2X2 feet could produce 20 pounds of fruit over the season or over 5 pounds per square foot but if you consider the amount of space required to get to the plant from both sides of the row the true production per square foot is a lot lower
Calculating production within the drip line of individual plants or row of plants will result in a higher number than for commercial settings that include inter-row spacing.
For bushes in a backyard setting, include all spaces to access the plant and intentional spaces used to avoid crowding or shading nearby plants.
These musings are strictly for backyard or small orchard settings. As stated commercial operations are a compromise of yield vs. labor; I think I read somewhere that the profit margin for an acre of high density apple orchard is $2,500 per acre? My guess is that any way that makes the trees more productive come at the cost of efficiencies that then cost more labor than it can be gained from volume.
If your idea of harvesting technology revolves around a tarp and a good shake of the tree it doesn’t take that much space at all 
Thee is a huge difference between a big commercial orchard which sells 500 acres of apples wholesale for a very low price (sometimes less than cost) and a small commercial orchard (like mine) who sells fruit to the local market for a retail price. In many ways the small commercial orchard is very similar to a backyard orchard except for the fact that I sell what I grow for a profit. Although I enjoy growing stuff, I would not bother to grow anything if my expected profit was only $2500/acre
I live in a tough area to grow apples but if I calculate the yield of my high density apples in a manor similar to the way you calculated the yield efficiency for your 250 pounds of apples for 10 X 10 feet of canopy, I get a big number too. In a good year I produce about a bushel (40#) of apples in a 3 foot X 3 foot space or over 4 pounds per square foot.
I guess the bottom line is that the yield productivity numbers vary greatly depending on how they are are calculated. If my real yield on apples was 4 pounds per square foot I would be rich!
Yes, 1000 times, yes. At my place I’d say the Romance cherries produce the most volume of berries, but without a GOOD NET the yield would be among the lowest of all bushes and brambles. It just blows my mind how many and how fast my unprotected cherries are stolen by birds. So yea, absolutely Don needs to consider that!
I get where you are coming from. The sad reality is that we live in a world of industrial farming; our competitive edge is based on an economy of scales that makes small production unworkable. Take wheat, a bushel is 60 pounds, the wholesale price is currently $7 per bushel. An acre produces on average about 40 bushels, so that’s $280 gross, before all the expenses are accounted for. You have to admit that under that light $2,500 from an acre of apples starts looking mighty attractive.
Even attempting to tap the retail market directly is not that profitable; retailing is extremely labor intensive. What has been effective for me and my microscopic orchard (15 trees, as many bushes, probably hitting 20 each when everything is said and done?) has been selling plants. My Northline Saskatoon is grossing me $70 this year, I transplanted 8 suckers, keeping one and selling the rest for $10 a pop. No way I could efficiently sell the fruit and even if I did it would be a time and labor intensive endeavor.
I don’t have that problem. The Robins around here are picky; as long as there are haskaps they’ll leave the cherries alone 
The real price of produce is eternal vigilance.
I think blueberries can last longer in refrigeration, and are more forgiving in terms of being picked before peak greatness, but I have experienced the blackberries which I picked under ripe are bitter and sour and sometimes when they are sweet and perfectly ripe, they become extremely soft and fragile, hence may not be practical for retail sale and storage
That’s great- you are a lucky man! Interestingly, I don’t think I’ve ever seen a robin in my cherries. In order of enemies it is always: 1) Catbirds/Mocking Birds (hard to tell difference at distance), 2) Cardinals, 3) Wood Thrush, 4) Blue Jays.
Speaking of your birds going after haskaps first, I’ve read some people say they plant “diversion” trees/plants for the purpose of providing a preferential food to divert birds from something they like better. Sounds like your haskaps do that- though it might not be your prefence for birds to eat them instead of cherries? But I’ve always wondered if the idea of a diversion feed might not work the way Japanese Beetle Traps do…In other words, they certainly will feed wildlife but they might bring in more birds than otherwise would come and many of the newly attracted birds then end up eating cherries. In other words, I wonder if the net effect of diversion crops might be a net loss of what is trying to be protected??? Probably never know for sure, just something I think about. Might even be true for same species of fruit…If I have one Romance cherry bush I’ll have a limited number of birds that feed on it. If i have 3, there will be more cherries but also more birds. I would think at some point the higher number of trees would mean more net cherries survive, but I’m not sure- especially over long term the population might just grow to meet the food availability? hmmm.
i suspect a large factor in this is due to the easier mechanical harvesting of blueberries. (ie, graft on sparkelberry, have a machine with a catch net under the stemmed bush and just shake to bush for harvest)
As far as im aware there’s not a efficient mechanical harvester for fresh undamaged blackberries.
Strawberries can be quite productive.
So can grapes. If also seen monster harvests of quince. But dunno if your area is fire blight prone. However, as far as im aware apple is one of if not the highest yielding fruit per surface. (in current comercial production) surpased by tomoto if you consider that a fruit.
I think however it’s an unfair comparison if you compare something low vs something high. The shadow the higher bush will trow, might decrease the yield of the next plant due to shading.
If you take shading into account. And don’t mind shading of walkways. you could use http://shadowcalculator.eu/
If discribed how to use it in more detail in this post.
If used it to determine the shade length a tree gives. For me for a east west row, the shade length is approx the tree hight. So im makeing that my row width.
Another way to increase yield is planting something that loves full sun. Like an apple tree growin in Future Orchards Library | Apple & Pear Australia Ltd (APAL) style.
And plant something like goosberries that tolerate the semi shade that tree creates in the shade of that tree. This will likely increase effective yield per sq feet.
Although i like productive fruit plants. I think a more intresting question is how to maximise yield, for most fruits.
I think maximizing light interception and airflow. Minimizing unwanted shading and disease and unwanted overly vigerous growth would be an excelent way to go.