Citrus > Cold Hardy Citrus

Precocity and tree caliper


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 .

Interesting.  Could it also be the extra warmth has an effect of the plant hormones related to fruiting phase?

I've recently seen suggestions that cold temperatures that aren't lethal may contribute to initiation of phase change. Summer temperatures get rather high, as only the polyfilm ends are removed. As the interior has filled up with growth, ventilation has been reduced. I use cooling misters on the hottest days.
Possibly, both temperature extremes have an effect on maturation, but I don't have any data to support the idea.

I think this phenomenon fits very well with the node count theory. Your trees have grown very fast and have reached the crucial height, that's why they are flowering .
From the reverse I can report that Poncirus hybrids here in northern Germany lack summer warmth and grow very slowly, mature poorly and often freeze back and stay immature for a long time.
Your trees have a long growing season a warm climate in the greenhouse and probably a good supply of nutrients. That speeds things up.
Ichangensis hybrids often start flowering on the lower branches first, interestingly ichangensis hybrids flower much faster and at lower heights than poncirush hybrids here even outside. In the greenhouse I had the first fruits in the 3rd summer at just about 1m height and that on the lower branches.
I think fast growth is very important, the genetic predispositions also play an important role and with fast growth these are fulfilled faster.


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