Mine came with a super tiny measuring spoon … something like 1/20th tsp. With that it is not hard to measure quantities. It also had instructions of concentrations based on this measuring spoon. If you don’t have such a spoon, use the smallest you have, say 1/4 tsp, then divide into say 10 equal piles and you have 1/40th of a tsp in each pile. To figure out the weight, weigh say one tsp and you can figure out the weight of 1/40th tsp from that weight - divide by 40.
BTW I think I bought it on eBay, there were a bunch of sellers there.
GA3 is dissolved into alcohol, not water. So first stir GA3 in alcohol until totally dissolved, then mix with water. Monopotassium phosphate can increase its effect on jujube. If you don’t have monopotassium, it can also work. 10-20ppm
I wouldn’t say fine, but it did eventually dissolve. I used water for 2 reasons:
1.) My wife wasn’t home, so I didn’t know where the rubbing alcohol was
2.) I saw another reference which said that GA3 had a solubility in 20 deg C water of 5g per L.
Since I was dissolving ~0.5g (1/8 of a tsp) in 500ml (about 1/5 of the max), I figured I’d be fine. But, it still took quite a while. In fact, while I was waiting, my wife got home and I dissolved another 0.5g with alcohol. But, by the time I was done with that, the water-based one was dissolved, so I went mostly with that. I took 19ml from the water mix and 4 ml from the one with a bit of alcohol (both about 1000ppm), then mixed it with ~1000ml in a spray bottle. So my target was actually about 23ppm. But, it probably isn’t that exact, given the initial measurement with the 1/8 tsp. I did double-check the weight of the 1/8 tsp and it was right on the line between 0 and 1 grams, so that is the right ballpark.
If I got it slightly higher (say 30ppm), I don’t think it would be too bad, given the study that used 0, 20, 40, 60, and 80 ppm didn’t mention any negatives about the higher concentrations. You would just want to avoid something like the initial mix (1000ppm).
My idea of spraying before dawn was to go out in the yard with a head-lamp around 1:30am. I ended up using up about half the bottle (about 500ml) and sprayed 10 whole trees and parts of 3 others. I’ve noted which branches were sprayed/skipped, so I should be able to see if there is a localized impact.
Two trees that I skipped completely were the Bok Jo/Sugar Cane/Tae Sang Wang multi-graft and the Xu Zhou which both have decent set already. Especially the multi-graft, which I’m actually tempted to thin- there are places where there are several 6" stems, each with 8-10 fruit.
Of the 3 where I sprayed only part:
One of the Shanxi Li had heavy set 2 years ago and then dropped them all. So, this time I sprayed half the tree and will be interested to see how the fruit holds.
On the big So (oldest and largest jujube), I sprayed only one branch, so I can see if it stands out
On a Honey Jar with some set, I skipped one branch
I also got mine from eBay and the instructions did say to dissolve in alcohol first. I did it 2 years ago and my notes didn’t really show much of a difference in fruit set on jujube. (Though that year was a bad year for all my juju’s.
One of the whole trees I sprayed is Sherwood. It has grown well, but never produced a single fruitlet, at least as far as I know. I was just looking at it almost 36 hours after the treatment and I see what looks like a fruitlet forming. I’m not sure how long it takes to go from flower to tiny fruit, but I see several others in the late flower stage with a slight bump forming in the middle.
That’s why I didn’t spray them I’ll fell pretty silly if they drop their fruit and are out-produced by the sprayed trees which had little set.
I would have liked to do it like a fully controlled experiment- say long rows of uniform varieties different in alternating rows for pollination, etc. Then spray 3, skip 3, spray 3, etc for the length of each row. Then you could take the middle tree from each set (to factor out over-spray, etc) and have some really solid conclusions. Of course, you would also want to vary the concentration, the number of times, how early, etc. Instead, I tried to leave enough variety that I can get some hints, without having unimpeachable data.
I just used an old Windex-type bottle, after cleaning it out well. It’s capacity is ~950ml and I’ve used up 80-90% of it, after spraying trees at 4 other properties (another dozen trees) and giving the ones I did last time another quick (less thorough) spritz, though it was misting a bit at 2 of the properties and started misting after the 2nd treatment at mine (radar had said the rain was over…), so I’m not sure how much that will impact things. The next few days will be sunny and warm, so I wanted to make sure to get the sprays in.
Regarding when to spray, you did it in the middle of the night. I wonder if it matters to spray it at dusk instead of getting up at dawn to do it? Will GA3 work sitting on the flowers all night? Does it need to get sunlight soon after spraying?
Most common is foliar spray and the literature came with the material said not to spray on the fruit of the plant. That is an issue because I have some fruit esp. Honey Jar have already set. It is not possible to spray the leaves without hitting the fruit.
What do you guys do? I guess my spraying with GA3 is a bit late this year but I still want to try it.
I’ll fell pretty silly if they drop their fruit and are out-produced by the sprayed trees which had little set.