I noticed that the limbs on my trees that have the most blooms/buds are the ones that are arching downward. Does anyone know if this is related to plant hormones or maturity of the limbs. There are a few of the limbs that are growing straight up that have blooms, but not nearly as many as the ones hanging down.

If it is hormonal, would it help to force the limbs to arch downward?

It is one of the tips suggested to force apples and pears to produce blooms. I don't know if it works with citruses.

On my containerized Cara-Cara, the grafted scion grew several inches up, did a 90 degree turn, split into two branches, then continue growing horizontally, parallel to the ground (left side of picture). It is funny lookin'!

I am sure a lot of Buyers rejected the tree because of its appearance, but I bought it anyway at Home Depot (last year). Something in the back of my mind said it was special/unique.

Well, as of now, every leaf on those two horizontal branches/trunk, all the way down to where it did a right angle, are sprouting out baby branches. Some have two+ branches growing out of the one leaf node. I think the apical dominance was lost on this tree when it did the 90 degree left turn. Don't know why it made that sharp turn though.

There is another branch (right side of picture) that is growing out of the scion, but at about a 30 degree angle. MANY buds and sprouts on that branch as well.

Overall, there are TONS of buds on this young tree, even along area of branches that don't have a leaf (most of those buds are sprouting too).

This tree, ugly was it may be, is a winner.

My observation is that branches growing close to 0 or 180 degree angle have more buds and sprout than the ones growing up (towards 90 degree angle).

As a citrus limb grows and matures it is the weight and length of the limb, plus any fruit, that causes the limb to begin to move to a horizontal, then a downward growth pattern. I believe the greater blooming has to due with the size and maturity of the branch rather than the directional growth.. - Millet

If you observe closely how citrus canopy is built through the years it is similar to flowers opening.

The branches that become loaded with fruits will droop down towards the ground and the existing canopy opens up. this would then allow sprouts on the bent limbs as well as the top limbs begin to sprout new branches and the canopy closes again. The sequence is repeated yearly. That's the pattern of how most of my citrus canopies develop as they become bigger, grafted or not.

I visited one of my sisters today and her grapefruit tree is in the middle of a heavy flush, but like my Ponkan, the limbs that are loaded with bloom buds are almost always the arching out and downward--most of them on the lower 1/3 of the tree. There are large vigorous limbs growing almost straight with lots of flushes up near the top, but no bloosoms. She does have one limb of an orange graft near the top that is going to have a lot of blooms, but it is one of 4 limbs coming out of that graft and it is growing diagonal.

I am going to try some experiments with my Ponkan and take some of the new growth and weight it down to form an arch. I will compare them to same age limbs that are left to grow almost straight up at bloom time next yr.

I think it is possible that the hormone secreted at the growing tip, if it is forced to stay in the tip due to gravity, may stimulate the differentation into blooms. It is my understanding that the hormone from the apical tip flows down the limb due to gravity and that is why tying the end down is one of the methods used to force buds. What does that hormone due during the winter when the tree is resting?

Skeeter, on second thought you might have a valid point concerning the horizontal position of a citrus branch and additional flowering. The auxins produced by terminal bud apical dominance retards the development of buds lower on the branch. With the branch in a horizontal position, the apical dominance is lost of lowered, and the auxins are therefore also reduced. Auxins may effect flowering through their roll in apical dominance, as suggested by the fact that bending of stems increases flowering in lemons. I am not sure about oranges. - Millet

The observation that let me to the thought was on my Ponkan. Ponkans have a general upright growth pattern, so there aren't many limbs that have that arch shape--it just happened that both of those limbs are the only ones showing bloom buds at this time. Ponkan is also one of the trees known for alternate bearing. If the process of bending the limbs downward works to stimulate bloom buds, it may be helpful in reducing the alternate year problem.

My Oro Blancos could be the exception. Almost all of the branches are horizontal or drooping, but only a few of them have blooms. But those few are more than enough for me.

That is a good point Steve, it makes me think I should wait until fall to bend them down, however as far as cold stress can go to stimulate bloom, we had plenty--I would guess that most trees here are at least a couple weeks later than normal due to the cold we had this winter.