The Tropical Fruit Forum

Genetics is an obvious factor involved in determining first flowering and fruiting of seedling trees. Another likely factor is the amount of resources the seedling has to utilize to establish trunk stiffening and thickening in order to brace against wind stresses. Trees secured against framework such as trellises and espaliers don't need to allocate as many resources towards trunk and limb framework. Seedlings within an enclosure with a poly or glass skin are also free to transition more quickly to a reproductive phase change. My trees grown outdoors are invariably shorter as well as stockier with thicker trunks. The trees within the high tunnel are lankier and taller. Almost all of my "precocious" trees were located within the cold frame structure .

https://www.youtube.com/watch?v=IBf04qhhghU
Video in monotone Spanish showing plate grafting, using as many as 5 buds at a time. Rather wasteful of buds, but increases the chances of success. The use of white paint is to semi-permanently indicate the location of the graft.
This procedure is probably only practical for top working established Citrus, not seedling rootstock. I've used a simpler form of this successfully.

In past experience I noticed that the first flowers on Poncirus and Poncirus hybrid seedlings tend to be skewed towards staminate flowers, rather than perfect flowers. This is quite evident in 6 trees blooming for the first time this Spring.

However, as I'm presently pollinating about a hundred Poncirus flowers with Meyer lemon pollen it's very apparent there's a pattern to the distribution of perfect and staminate flowers on mature Poncirus. On each flowering twig the first 3, or so flowers at the outer end of the twig are perfect (having both anthers and pistils). The remaining flowers farther back on the twig are almost all staminate (anthers only).

Additionally, the flowers in the intermediate position often show partially developed pistils.
Although I was aware of the two types of flowers previously, I never noticed that the flower position had such a profound influence on the development of flower type. I'm curious if this applies to other Citrus types.


Staminate flower on the right with anthers about a day before dehiscence. Pistil is undeveloped and non-functional. The flower on the left is perfect (complete).


Perfect flower showing prominent pistil, as well as anthers.

It's probably unnecessary to mention that flowers without pistils can provide pollen, but have no chance of developing into fruit themselves.

Early in 2021 I planted a number of Bishop segentrandarin seeds. I lost some due to overheating, but had 5 surviving seedlings. After considerable neglect, these were collected today and moved into the cold frame. HardyVermont had feared they were largely nucellar. I did notice some variability early on, but was surprised today, when it appears most, if not all, are clearly zygotic seedlings. The largest one is predominately monofoliate, as is a second smaller seedling. All differ from each other in frost resistance, leaf shape, etc.

I found Bishop to quite palatable once diluted. It's acidic, yet sweet. Poncirus tastes are minor and fleeting, it's the best tasting Poncirus hybrid I've tasted (I haven't tasted many). To this point my experiences have been much more seedling related, than fruit related, I hope that changes shortly!
 

This American persimmon is the result of 200 American persimmon seedling rootstocks that were abandoned due to graft incompatibilities with D Kali. One of the female trees is a very prolific bearer of oblate fruit. Unlike the remainder of the trees, this selection retains the fruit quite well, even while ripening, allowing many of the fruit to be eaten directly from the tree, upon softening. A few actually dry on the tree and remain on during the Winter.

I'm considering propagating a few trees in the Spring.

A dried fruit left over from last Autumn.


The tree is shorter than the other trees, about one half the height.


A view of this year's fruit set.


Another view of the fruit set at present.

Informative video concerning preparing Citrus prior to a freeze event, and assessing post-freeze damage. Applicable for standard Citrus, as well as cold hardy Citrus.

 https://www.youtube.com/watch?v=Hyz3McFqeHU

I'm considering top grafting Kaffir Lime onto 6-8 year old Poncirus trees in the late Spring. This would only be for the duration of the season, knowing that Fall temperatures would quickly kill them off.
Does anyone have experience doing this and was the resulting growth worth the effort? If successful, I may be eating a lot of Thai food next Summer!

https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=43947

I actually thought it had been sequenced earlier. Now we need to harness it's deciduous and cold hardy properties.

Conestoga #002, nearly thornless selection. Nice to see after dealing with Poncirus.

Repurposed dog nail clippers works just fine for thorn removal on 400 Poncirus yearling rootstocks. Unlike the dog, the seedlings don't squirm in the process!

I've noticed a twig with 3 consecutive sets of paired thorns on a F2 citrange specimen. Some distant Citrus relatives are armed with paired thorns,(Hesperethusa crenulata on occasion) I'm not certain how common this feature is among Citrus. Hesperethusa's compound leaves have a resemblance to Poncirus, although fruits and bark are quite different.

I see there's an additional pair at the base of the scion.

Is anyone familiar with both TiaTri citrandarin and 5* citrumelo in respect to their winter hardiness? The first indications I see are that TaiTri shows a bit of deciduousness while I see none in the 5* at this point.  Some of my segentrages show appreciable deciduous behavior, others don't. TaiTri also made less late growth. Which has shown better cold resistance?

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.


Scion donor F2 citrange plant.


Scion severed from donor.


Epidermis shaved off of scion side 1.


Epidermis shaved off of scion side 2.


Shallow downward cut on rootstock - avoid cutting into wood.


Scion ready for insertion. Leaf area has been reduced to 25-30% to reduce transpiration.


Scion fitted for insertion.


Graft wrapped with parafilm.


Completed graft showing flush of growth present at time of grafting.


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