We have a IKKJ growing in a 42’ geodesic grow dome in Wisconsin. She is about 2 years old and approximately 4 feet tall. Her trunk is VERY thin and she needs support. She had three fruit growing already but all of them eventually fell off. Any advise in regards to fruit set?
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Let the tree get bigger, it will hold more fruit. Welcome to the forum!
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Wow, that sounds interesting. I’d love to see your setup.
With regards to the tree, it sounds like it may not be getting enough light. I could see that being an issue in a greenhouse in WI. Do you think that could be the case? What covering is on the GH? Shadecloth? Anything else that would lower light like big trees nearby?
I have had persimmons in my GH in the past. They were productive. Light in my GH is about 50% of outside. I just bought an instrument to measure daily light integral, DLI, so I’ll know a little more soon.
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We have 50% shade cloths on currently. The grow dome is constructed of polycarb. The persimmon is located centrally in the dome where there isn’t a shade so I don’t think that’s it. We water her with the pond filter water. Maybe that’s too much fertilizer? I will post a picture tomorrow. Thanks so much for the advice.
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Thank you so much 
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Movement from wind helps stems/trunks to strengthen/thicken, so that could be a factor if there’s no wind inside. Also too much nitrogen might cause rapid, spindly growth. I don’t have much experience, just some ideas from what I’ve read that you might want to research further.
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I think your persimmon is just too small and young to hold fruit. My second year persimmon had a lot of flowers this year and didn’t set any fruit. Persimmons first grow roots. Then a top and then set fruit. Ours both need another year or two at the least to set fruit.
Mine is a much more compact tree. But it’s not growing like yours. As much as it will hurt you probably need to prune it back when dormant. That will stiffen up the structure enough that it can bear the weight of some fruit. It’s either that or build a frame or big stakes for support.
I love your setup. Please post more pictures and content when you can. Lots of people will be interested.
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The internodal distance does look a bit long, suggesting it’s probably on the low end of light exposure. But it looks good otherwise and clearly it’s getting enough light to flower. It’ll just grow a little leggier.
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Here is a in ground, full sun … southern Tennessee comparison.
I started this one in ground last spring… it was a tiny thing… so it has one growing season and a few months behind it at this point.
It put on a lot of low branches last year which I removed with late winter pruning. Trying to get all fruiting branches to establish high enough to minimize deer problems.
It is getting close to 8 ft tall now.
Lots of branches developing above the 5 ft line.
That is my IKKJiro.
TNHunter
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I didn’t want to belabor the light issue. But the optimum daily light integral, DLI, for fruit trees is 30-40+. In a greenhouse in WI with 50% shade cloth that light level is impossible. Light in that greenhouse is probably 50% of optimum in summer and way less the rest of the year. I think the tree will produce fruit. It’s out in the open so that helps. If it were surrounded by other big plants, it would be much worse.
The best I can do in my GH in a very sunny climate is to average DLI of 25 in summer and half that in winter. My GH has no shade cloth and nothing nearby to cast shade.
I haven’t been measuring DLI in my GH for very long. But on two recent days with 100% sunshine the DLI was 31. There’s no way I’ll ever measure more. That’s the longest daylight of the year and 100% sunshine. It’s all downhill from here. That is enough light to grow great fruit. I go for moderate yield and high quality. If I insisted on maximizing yield, quality would suffer.
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That’s interesting as all our citrus trees, figs, papaya and peanut butter all have fruit 
I sense a challenge in the air 
. We shall see how it goes with the ichi ki kie jiro. She is only going into her second year so. Thank you so much for the information. Now we wait.
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I do think you’ll get fruit. Good luck.!
When the tree gets big enough that you want it to stop growing and start producing you should avoid fertilizer since it can cause fruit drop. But for the next few year or two, you should want it to grow.
I have one IKKJ which surprised me with 5-10 fruit in year #3. Another is frustrating me a bit with no fruit in year #5. Neither got fertilized this spring, but I am still fertilizing this persimmon (which is in year #3 now. Maybe next year it will be big enough for fruiting.
What device did you get to measure this? I just got a light meter (arrived today) and I turned on my winter light setup to check it out. The top shelf (where I was growing jujube seedlings) ranged from 30 klux to 60 klux. From online, I found that the sun at noon is ~100 klux and British summer sun is 50 klux. So, my setup on average is a bit less than a British summer. I’ll play with it outside tomorrow to get a sense for what our summer sun is like…
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I bought this for $30 off amazon AH-20 DLI Meter Sunlight Calculator Daily Light Integral Record MOL/(㎡d) for 10 Days: Amazon.com: Industrial & Scientific
So far it’s working like a charm. I wish I had bought two so I could compare locations like outside vs greenhouse at the same time. I think I’ll order another right now.
OK, I think I see why I bought a different model. The one I got gives a real-time measurement of the lux, while yours gives a par reading over a day, so it seems like they do different things. I don’t regret getting mine, but I think I will order the one you got as well.
Using mine, at 11:30am EDT (so, 10:30am solar), outside was 84 klux. Through the sliding door was 45 klux, and through the door with a screen was 24 klux. It makes sense that the screen would filter some light, but I had no idea it would be that much. It looks like next winter I will be removing the screen for the plants growing in my window.
If I use it to compare the sun levels of different trees, I guess I’ll need to mount it at the top, maybe on the support post. Otherwise the tree itself will shade the measurement…
I ordered another one. I want to compare greenhouse to outside same day. That’s the only way I’ll know for sure how my greenhouse stacks up on light level.
I’d think that DLI is a much better way to compare and contrast locations for fruit suitability. You and I can compare and contrast our light levels. Alan thinks his area has too much cloudy weather many years to grow good fruit.
We often have questions from growers about whether X hours of sun is enough for a certain fruit. DLI is the answer.
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One other interesting note. I measured again at 1pm (noon without DST) and got 89 (outside), 42 (glass), 20 screen.
10:30: 84 / 45 / 24
noon: 89 / 42 / 20
So, it is interesting that with more light at noon, the inside values are lower, likely because the angle they are hitting the window and screen is less direct. Basically, the window and earth’s surface/atmosphere are perpendicular to each other, so the more direct the sun from overhead, the less direct through the window. Maybe it’s obvious and I’m easily impressed, but seeing this in action is pretty neat.
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