Tropical Fruit Forum - International Tropical Fruit Growers

Citrus => Citrus General Discussion => Topic started by: kumin on June 29, 2019, 07:53:00 AM

Title: Small diameter scion Bark Flap Citrus graft
Post by: kumin on June 29, 2019, 07:53:00 AM
Photos of a simple graft for joining a small diameter scion with a range of similar or larger diameter actively growing rootstocks. These have worked very well for me in the past.

Selected Poncirus rootstock.
(https://i.postimg.cc/jL7TLby7/Selected-rootstock.jpg) (https://postimg.cc/jL7TLby7)

Scion donor F2 citrange plant.
(https://i.postimg.cc/hhQ600hF/Scion-donor-F2-Segentrange.jpg) (https://postimg.cc/hhQ600hF)

Scion severed from donor.
(https://i.postimg.cc/dDWRLMJw/Scion-removed-from-donor-tree.jpg) (https://postimg.cc/dDWRLMJw)

Epidermis shaved off of scion side 1.
(https://i.postimg.cc/4m9KZjd8/Epidermis-removed-from-side-one-cambium-remaining.jpg) (https://postimg.cc/4m9KZjd8)

Epidermis shaved off of scion side 2.
(https://i.postimg.cc/tsbgbT8T/Epidermis-removed-from-side-2.jpg) (https://postimg.cc/tsbgbT8T)

Shallow downward cut on rootstock - avoid cutting into wood.
(https://i.postimg.cc/fV5Mhvx2/Rootstook-prepared-for-scion.jpg) (https://postimg.cc/fV5Mhvx2)

Scion ready for insertion. Leaf area has been reduced to 25-30% to reduce transpiration.
(https://i.postimg.cc/R33yb1Gn/Scion-ready-for-insertion.jpg) (https://postimg.cc/R33yb1Gn)

Scion fitted for insertion.
(https://i.postimg.cc/yk1Vp5Rg/Scion-inserted-cambium-matched-to-follow.jpg) (https://postimg.cc/yk1Vp5Rg)

Graft wrapped with parafilm.
(https://i.postimg.cc/D42KDJSk/Graft-wrapped-with-parafilm.jpg) (https://postimg.cc/D42KDJSk)

Completed graft showing flush of growth present at time of grafting.
(https://i.postimg.cc/5Q9Zghrf/Graft-complete-note-rootstock-is-in-active-growth.jpg) (https://postimg.cc/5Q9Zghrf)

An example of this type of graft after 18 days. This graft will be re-wrapped until healing is complete.

(https://i.postimg.cc/TKzdYPKF/18-day-old-graft-begining-to-knit-together-growth-not-forced-a.jpg) (https://postimg.cc/TKzdYPKF)
Title: Re: My favorite small diameter scion Citrus graft
Post by: Kelley_GA8a on June 29, 2019, 08:25:46 AM
Thanks for the photos, Kumin! Can you do multiple grafts on one rootstock? Did you cover the graft or just use the parafilm? I have several rootstock trees that are too large to cleft graft, so I was going to resort to t-bud grafts. I recently tried a few cleft grafts, leaving the top two leaves on and unwrapped. We’ll see what happens.

(https://i.postimg.cc/w1FgZM3q/4-C7-A783-C-A261-4-A28-BE20-80-B46-ECC1-F20.jpg) (https://postimg.cc/w1FgZM3q)

(https://i.postimg.cc/crSWJwn1/A489-D5-DD-ABC8-414-B-9-B2-E-28-BB224-EB701.jpg) (https://postimg.cc/crSWJwn1)
Title: Re: My favorite small diameter scion Citrus graft
Post by: kumin on June 29, 2019, 10:25:50 AM
As the rootstock is initially not top pruned, the number of grafts is only limited by available stem height. I use parafilm alone when the temperatures are high enough to heal quickly. If the temperatures are cooler, I use a bit of white electrical tape to secure the parafilm, I don't like to use excessive electrical tape due to low stretch and remove it after several weeks.
Title: Re: My favorite small diameter scion Citrus graft
Post by: Samu on June 29, 2019, 12:11:00 PM
Another creative way of grafting;
I would like to try this method, thanks for sharing, Kumin!
Title: Re: Small diameter scion Citrus graft
Post by: kumin on June 29, 2019, 05:45:11 PM
Kelley_GA8a, to more fully answer your question regarding wrapping the graft: If the humidity is low and it's hot and windy, I will run parafilm up and down the graft to cover the entire graft area. Presently, humidity is high and I allow the small leaflets to remain unwrapped. It's all a matter of keeping an eye on the leaflets and avoiding desiccation. Additional wrap can be added or removed as required. Leaflets turning black, or drying up is not a good sign.
Title: Re: Small diameter scion Citrus graft
Post by: Laaz on June 29, 2019, 05:52:50 PM
You can also chip bud with high success on small diameter rootstock.
Title: Re: Small diameter scion Citrus graft
Post by: Bomand on July 03, 2019, 08:51:26 PM
I love to top work with small stock....like to use parafilm and a walmart veggie bag..very successful.
Title: Re: Small diameter scion Citrus graft
Post by: will2358 on July 11, 2019, 08:06:15 PM
Is that the veneer graft?
Title: Re: Small diameter scion Citrus graft
Post by: kumin on July 11, 2019, 09:00:21 PM
Despite similarities, this graft doesn't cut into the underlying wood on either the scion or the rootstock, except for the very end point of the scion.. The objective is to have cambium touching cambium on both sides of the scion. The length of the epidermis removed is the same on both sides of the scion. For best results when forcing the buds, it's important that the scion buds aren't too immature.
Title: Re: Small diameter scion Citrus graft
Post by: kumin on July 13, 2019, 06:02:02 PM
2 examples of buds emerging as the bark flap grafts are progressing. Practically all the grafts are alive at this point, and will hopefully emerge, providing the buds on the scions are mature enough.

(https://i.postimg.cc/64zsYHRB/Bark-flap-graft-1.jpg) (https://postimg.cc/64zsYHRB)

(https://i.postimg.cc/YhqjkZdf/Bark-flap-graft-2.jpg) (https://postimg.cc/YhqjkZdf)
Title: Re: Small diameter scion Bark Flap Citrus graft
Post by: sc4001992 on July 14, 2019, 06:24:05 AM
Kumin, excellent illustrations and explanation.
Thank you.
Title: Re: Small diameter scion Bark Flap Citrus graft
Post by: kumin on July 14, 2019, 09:31:47 AM
If the internodes are long enough it's possible to get one graft per bud from the scionwood.
Title: Re: Small diameter scion Bark Flap Citrus graft
Post by: kumin on August 02, 2019, 07:40:14 AM
The thought process that went into this graft/budding process is that a flap of bark loosened from the stem will heal back to the stem if immediately securely fastened to the stem. By inserting a thin scion with the cambium exposed on both sides, it will also be included in the healing tissues. When I initially started Citrus breeding decades ago, it was my only method of graftage.
Title: Re: Small diameter scion Bark Flap Citrus graft
Post by: sc4001992 on August 02, 2019, 08:06:11 AM
Your method works very good on these small scions.
Very helpful information.
Title: Re: Small diameter scion Bark Flap Citrus graft
Post by: Florian on August 03, 2019, 12:14:00 PM
Thanks for this excellent tutorial! I shall try this method too.
Title: Re: Small diameter scion Bark Flap Citrus graft
Post by: kumin on August 29, 2019, 11:44:23 AM
Follow up photos as these grafts have developed further. I'm pleased with most of the scions' growth. Next concern is getting the new growth to harden off for winter. The grafts made lower on the Poncirus rootstock appear to have grown more than the grafts placed higher. I don't know if this is only a temporary response or not.

(https://i.postimg.cc/V5ShWQwc/Scion-growth-Aug-28-2019.jpg) (https://postimg.cc/V5ShWQwc)

(https://i.postimg.cc/PpHmpDdx/Conestoga-010-Aug-28-2019.jpg) (https://postimg.cc/PpHmpDdx)

(https://i.postimg.cc/tnHswC0Z/Conestoga-011-Aug-28-2019.jpg) (https://postimg.cc/tnHswC0Z)
Title: Re: Small diameter scion Bark Flap Citrus graft
Post by: kumin on July 07, 2020, 06:08:28 PM
I've just completed 440 of these grafts. Percentage of successful takes might be off a bit due to hot weather. Hot, humid weather is preferable to hot dry weather in this instance.

The rootstock is of smaller caliper than ideal, which slowed down the process.
Title: Re: Small diameter scion Bark Flap Citrus graft
Post by: Millet on July 07, 2020, 08:16:47 PM
Looks like a easier graft for new beginners at grafting.  Good usable information, and with good pictures.
Title: Re: Small diameter scion Bark Flap Citrus graft
Post by: Seanny on July 08, 2020, 12:03:46 AM
I tried this on an old branch, among 2 T-budding.
Ended up with 1 good T-budding.

Title: Re: Small diameter scion Bark Flap Citrus graft
Post by: kumin on July 15, 2020, 09:38:20 PM
This summer I've started using a variant graft. A problem with the bark flap graft is keeping all 3 layers properly aligned during the parafilm wrapping procedure. There's a tendency for one or two of the layers to shift to the side during wrapping.

The change is cutting the slipping bark on the rootstock in the shape of an inverted "L". That's a vertical incision as in a "T" bud, but the top horizontal cut only goes in one direction, but farther, hence inverted"L". A very flat and slender scion has the epidermis and a sliver of cambium removed from each of the 2 sides (just as previously). The knife used must be very sharp to provide smooth edges.

The prepared scion is inserted and pushed firmly under the bark flap, with the scion bud sticking out of the top of the horizontal cut, if desired. Wrapping should be from the attached side to the open cut to securely hold the scion within the bark.

I find I'm able to complete these grafts faster and have a more stable finished graft.

Within 3 weeks the success rate of this graft should be able to be evaluated.

Prepared scion, cambium exposed on both sides.
(https://i.postimg.cc/HVTSJmfv/Scion-new-graft.jpg) (https://postimg.cc/HVTSJmfv)


Inverted  "L" cut in rootstock bark -don't cut into wood.
(https://i.postimg.cc/Bjr7nFsH/New-graft-rootstock-bark-cut.jpg) (https://postimg.cc/Bjr7nFsH)

Scion tucked securely to the left side - awaiting wrapping.
(https://i.postimg.cc/mthm3jg7/New-graft-ready-to-wrap-2.jpg) (https://postimg.cc/mthm3jg7)

Graft wrapping - note the rotation - from the attached side toward the cut side on the rootstock.
(https://i.postimg.cc/sBPmf0TC/New-graft-wrapping-from-attached-side.jpg) (https://postimg.cc/sBPmf0TC)
Title: Re: Small diameter scion Bark Flap Citrus graft
Post by: Seanny on July 16, 2020, 10:50:43 AM
Your graft is in a GH so no scion protection?
Title: Re: Small diameter scion Bark Flap Citrus graft
Post by: kumin on July 16, 2020, 01:01:30 PM
This graft is on an outdoor propagation bed.  The bed was covered when used for Citrus germination. It hasn't been heated, nor covered this season. I have an additional high tunnel, covered, but unheated. My cold hardy Citrus hybrids should need little, if any winter protection in a normal winter. The high tunnel is being used in an attempt to hasten maturity from seedling to mature, fruiting phase.

However, in the event of an extreme Arctic blast, it affords me the option to use emergency heat.

(https://i.postimg.cc/3yngBfJ7/IMG-20200716-130145.jpg) (https://postimg.cc/3yngBfJ7)

(https://i.postimg.cc/wyrDKtmG/IMG-20200716-130428.jpg) (https://postimg.cc/wyrDKtmG)

In regards to scion protection, it might be prudent in sunny, hot conditions, but I haven't done any misting, shading, etc. I bud/graft several hundred trees per year and pretty much let them fend for themselves, except for watering, weeding, removing suckers, and fertilizing.