Cross-Pollination of Mandarins

For varieties that are often listed as requiring cross-pollination, wouldn't it be more accurate to say "cross-pollination required to produce higher yields"?

What sort of yield can be expected for a tree that isn't cross-pollinated? Yield will of course depend on the variety but in what magnitude? (e.g. a dozen vs. dozens?) For the non-commercial grower, would this lower yield still be enough to satisify the average grower and with the added benefit of fruits containing fewer seeds?

 

Junglekeeper - I'm not sure I'm answering your question here, but some mandarins (such as the Satsuma) set fruit without pollination, which is defined as autonomic parthenocarpy. In at least two commercial groves that I am aware of, Tangelos are planted intermittently for the purpose that you described. Once again, I'm not sure that I have answered your question, but I hope I've brought you closer to an answer, at least. Take care.

 

I'm only wondering about varieties in which cross-pollination would be helpful. For example. What would happen if you plant a Minneloa tangelo without a pollinator?

 

Junglekeeper - Keep in mind that my professional experience involves container trees. I can tell you that most citrus is self-fertile, meaning they don't require cross pollination. On the other hand, Tangelos are planted in some groves to increase fruit set. So, in the opinions of some who make their livings producing citrus fruit, cross-pollination is good. But, as far as increasing the yield on Tangelos, I'm not rightly sure. Are there any commercial producers out there? (Sorry, my knowledge in this area is quite limited.)

 

Junglekeeper, to quickly answer your question...if you planted a Minneloa Tangelo with a pollinator so that cross pollination could occur, then the fruit crop produced by the Minneola Tangelo would GREATLY increase. The variety Mineola Tangelo is called "self imcompatible. Self incompatible means that the pollen is incompatible with the postils, even though the ovules of the flower are fertile. In other words the pollen is incapable of bringing about sexual fertilization even though both male and female components are functional. Incompatibility in citrus is due to slow pollen tube growth, apparently caused by inhibitors in the style. This results in abscission of the style BEFORE the pollen tube can enter the ovary and discharge it's sperm nucei into the embryo sac. Sexual fertilization is thereby precluded and fruit set of non-parthenocarpic varieties is nil to very little. Both Sunburst Mandarin and Temple are excellent polinators for Minneola Tangelos, and when cross pollination occurs your Minneola will produce a very good crop. However,also keep in miind that Minneola Tangelos are notorious for alternate bearing. If you do not have a Sunburst or a Temple, you can "pollinate" the Minneola blooms with Gibberellic Acid. GA sprays at 10ppm concentration applied from full bloom to two-thirds petal fall have effectively set and produced commercial size crops on Orlando and Minneolas. Fruits induced by GA are reduced in size and development of orange peel color is slightly delayed. BTW, if you want to try something fun to pollinate self-incompatible tangelos try this. When flowers are opened by hand well before the flower would normally open and self-pollinated by hand their self-incompatibility is many times ove come. It is not really known whether this was due to the very short style (thus shorter pollin tube growth), or to the absence of chemical inhibition in the style. Lastly Minneola are WEAKLY parthenocarpic so lack of sexual fertilizaton can result in some fruit, though usually nil. Hope I have helped to answer your needs. Take care, and good luck. - MIllet

 

Millet - That information is fascinating. I'm saving it for the archives. Thank you for your research on the matter. Question: Is giberrelic acid useful in increasing yield on trees in the autonomic parthenocarpy category?

 

Thanks for your informative reply, Millet. It may come in handy. It's always interesting to know the reasons why plants behave the way they do. To recap, the answer would be 'yes' and the expected yield of an unpollinated tree would depend on its degree of parthenocarpy?

My question didn't start off being about one of my trees but now I suspect one of the seed-grown plants is a Minneola based on my history of consumption and the help of Malcolm Manners' image collection of citrus leaves. The other seed-grown plant is likely a mandarin or mandarin-hybrid. Maybe these two trees will cross-pollinate each other one day.

 

AAE what do YOU meand YOUR saving my thread for the archives? What do YOU have to do with the archives of this forum? No I do not give YOU permission to do anything with my postings! - Millet

 

Millet, once we make a post the content can be used
by anyone. It is better to know the people that might
and would use the information to their benefit as
opposed to the people that we do not know instead.
I've had information I've posted in these forums used
by others that I personally would not have helped
but that is beyond my control other than not to post
sensitive information that I feel either others are
not ready to know and in some cases do not deserve
to know yet. The last statement has been my nemesis
in the UBC Maple forum.

Much of what we write and post for photos stays in
house but there are others that have snagged some
of the photos we have posted and are using them
for commercial purposes. It makes sense to use
a photo of a specimen Maple of ours in order to
try to sell one and two year old grafts but it also
sends up a red flag with me when I see that photo
used, that in effect once I posted it became the
ownership of the UBC Botanical Garden forum.
Had permission been asked for and granted by
the UBC then I have no complaints.

Content on the internet is fair game for anyone.
Even content about a specific Citrus variety
can be used by someone else, even for a book,
so we have to be careful at all times in who we
quote and in some cases paraphrase. I doubt
AAE will use the information you provided on
parthenocarpy of the Minneola Tangelo for
anything other than for personal reasons.
I have copies of web sites that are for me
only in that I do not let others see what
I have, nor will I share that information
with anyone. If AAE is making a copy of
the information from this forum, I would
think he would be rather wise to keep it and
read the information offline. So in effect
with your post you already gave permission
for others to use that information elsewhere.
It becomes a matter of what do they do with
the information is what may make us wish
we had not posted the information but we
have to know the negative side before we
ever make the post, as ultimately it was
us that decided to give the information
away so others can learn from it.

In regards to a Minneola Tangelo the trees
can still be cross pollinated by another
Minneola Tangelo. The tree is incapable
of being selfed. So, in Junglekeeper's
case most any nearby Citrus can act as
a pollinizer for his Minneola Tangelo.
For a while there was thought that indoor
Kaffir Limes needed a pollinizer so some
people bought two trees instead of one
so they could pollinize each other. The
Lime may be capable of producing one
or two Limes on its own but if we have
a second Lime we may get 8-10 Limes
on each tree. The problem here is that
the fruit has little use at this time. Most
people have the Limes for the leaves for
cooking and for teas. Even the leaves by
themselves are not very fragrant until
we crack or crush them and then their
aromatic perfumes will be liberated.

Jim

 

Well, I didn't find what AAE said to be out of line (although it wasn't necessary, as we've so far managed to keep all original discussions from the start of these forums in the database). That being said, I understand there's some history between some of the citrus forum participants, and it would be impossible to not carry their emotions over from other forums. I'll reiterate the mission of these forums, though: "the discussion is about plants, not about the people who discuss plants".

That's a hard thing to stick with, obviously, because without the people involved (scientists, horticulturists, gov't and industry people) there wouldn't be much to discuss.

I'll direct your attention to the article linked in this thread: http://www.botanicalgarden.ubc.ca/forums/showthread.php?t=5225

These forums are currently high signal to noise, and I'd like for them to stay that way. I'm locking the thread, but feel free to reopen the discussion on cross-pollination of mandarins (or request that I copy most of the thread over so the discussion can continue on). Or, if you'd like to comment on the closing of the thread, the forum feedback area is always open.