I am sure some of you might have observed this before and thought of some reasons for it.

I have some two or three months old rooted fig plant placed on a table in front of a window getting afternoon sun. Recently I noticed that most, if not all, of these plants show signs of dried up apical (terminal) bud while the older opened leaves look healthy (and hoping they stay this way).  What different reasons can cause this drying up of apical (terminal) buds.

Condensation dropping on such buds in humidity chamber can rot the buds but these plants are not in any chamber but in an open room.

I have seen similar to mine but the little buds trying to sprout instead of drying out just seem to stay tiny and not do anything and then slowly come about and grow, what i suspect and just a guess is that the root system could not handle everything trying to grow and shut down some production for the rest of plant to get its needed nourishment.
Mine i speak of are about 3 months old under grow light no humidity dome either.
Just a guess.

I've seen the same thing on my recently rooted cuttings. I notice it after there is a change in conditions and growth is interupted. For example - after potting, moving from high humidity to ambient conditions, or introduction to light. In most cases, when new growth resumes, they shed the outer dried bud and begin to grow again. Another thing to consider could be fertilization. I was over fertilizing some of these young plants which caused growth to halt (probably from root damage). After reducing or stopping fertilization the growth resumed.

Referring to Dan post above.
My rooted plants were inside the living room on a table thriving well for a months before the apical buds showed these signs. Does the dew point issue still apply?
My suspicion, but just a suspicion yet, is that ssometimes we get relative humidity down in the range of 15~25% for the duration when when it gets very cold overnight and the furnace fires frequently drying up the air because of closed air circulation (especially when the fresh air draft leakage from outside has been minimized) but then it goes up again when it is not very cold and the furnace fires less frequently. Some plants may not be able to compensate for moisture transpiration/dessication because of less roots than required. Could this be the possibility?
I am not sure if it is a fair question to ask if there is a minimum relative humidity level when the the newly rooted plants will be at risk of losing apical buds or other developed leaves (because it all depends on the moisture intake capability of the available roots and available moisture)? Comments will be appreciated.

(PS: I wish mid-May comes sooner than scheduled...then it will be a different ball-game)

Ottawan,

I have forced hot air heat and the humidity varies radically sometimes like you mention. I think that change in humidity is exactly what I observed with changes in conditions. Dan's citing of dew point is the same thing - changes in conditions.

Another example ... I had one cutting that I potted a few days ago and put a humidity dome on it (bag). It was doing fine. This morning I removed it and when I got home tonight it has almost completely wilted. The humidity is very low the past few days with the cold and wind and the heat firing.

Here is some sort of dew point calculator
Dew Point Calculator

I do not venture into this area so i do not know anything about ,
if it helps great if not disregard

Dan,

I would certainly agree with you on the fact that condensation will happen as you describe. I am not sure that is what is causing the drying of Ottawan's terminal buds. I am guessing because I can not see the plants or measure the conditions ... but, I have seen this when the humidity drops (caused by heat, sun, or one of many other reasons). They should bounce back fine when acclimated to whatever changing conditions there are.

Marty,
Thanks for the link to that calculator - that will be useful.

Well, life for the little dear figs inside the house is getting complicated....
Hurry up the real spring (because the calendar spring does not work here!).

Dan, I again I agree with you about the fact that condensation occurs in the ways you are saying (for the record, I have a degree in physics - hence my interest in experimenting). So I am not disagreeing with you about condensation occurring. I just have not observed that condensation leads to the drying of the terminal buds. It may be a factor in some cases, but without quantifiably measuring the conditions and correlating results, you can not be so sure. In the absence of having that type of measurements and data, you can only go on what you see empirically - which in my case has been changes in conditions (including humidity) slows or halts growth, and gives the observable drying of the bud.

So we agree to disagree - which is OK. Varying opinions lead to some good discussions.