Can keiki paste start new crown growth after prolonged setback

[Beallara49]

I have a NOID mini-phalaenopsis which went 20 months with no new leaves or flower spike. It did grow aerial roots. I applied keiki paste to a node on an old flower spike and to the crown, just to see if it would help. About four weeks later, almost simultaneously, I got new growth at the node and the beginning of a new leaf at the crown. The new flower spike didn't make it, but the new leaf continued to grow. Was this coincidence, did the keiki paste "jumpstart" new growth, or did it actually trigger a keiki from the crown?

[neophyte]

the keiki paste encouraged new growth from the mother plant, not a basal keiki (which would have started from one of the intersections between the older leaves, not the newest ones).

keiki paste contains cytokinins, which are a family of plant hormones that encourage cell division and act in concert with another family of plant hormones called auxins to produce shoots (stems/leaves) or roots. whether the plant produces roots or shoots depends on the ratio of cytokinin to auxin. when there is more cytokinin, the plant develops shoots. when there is more auxin, the plant develops roots. when the ratio is the same, the plant forms neither roots nor shoots. it could be that your plant was just making lots of auxin or not enough cytokinin (or both), but it could be a variety of other reasons too. however, the hormonal imbalance introduced by the keiki paste probably did contribute to the plant's production of a new leaf.

[Ray]

Originally Posted by neophyte

keiki paste contains cytokinins, which are a family of plant hormones that encourage cell division and act in concert with another family of plant hormones called auxins to produce shoots (stems/leaves) or roots. whether the plant produces roots or shoots depends on the ratio of cytokinin to auxin. when there is more cytokinin, the plant develops shoots. when there is more auxin, the plant develops roots. when the ratio is the same, the plant forms neither roots nor shoots. it could be that your plant was just making lots of auxin or not enough cytokinin (or both), but it could be a variety of other reasons too. however, the hormonal imbalance introduced by the keiki paste probably did contribute to the plant's production of a new leaf.

If you are stimulating the plant by the application of hormones, the more likely outcome is "the plant forms either roots or shoots", and that will depend a lot upon the particular plant.

My guess is that the new growth was likely to happen in any case, but the keiki paste accelerated the process.

When roots grow, they produce cytokinins that move up the plant to stimulate shoot growth, so as roots were growing, that was happening already.

[neophyte]

sorry, what i meant when i said the ratio is the same is when the amount of cytokinin is equal to the amount of auxin. when the ratio is one-to-one, the cells form an undifferentiated callus (ie., a mass of cells that are neither specialized roots nor specialized shoots). however, a perfect one-to-one ratio would probably only ever happen under laboratory conditions (and even if the ratio was approximately 1 in the keiki paste, that wouldn't mean the plant itself would be in equilibrium).

so, as ray said, the application of hormones would most likely induce the plant to produce shoots or roots. in this case, the keiki paste, containing mostly cytokinins, shifted the ratio further towards conditions favoring shoot growth. like human testosterone supplements, the paste contained hormones in a much, much, much higher concentrated form than that secreted by the roots themselves, which sped up the process or shoot growth.