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long Island

As I am sure you are all aware buy now, my main vine has split in three places. The splits are drying and healing up nicely.
I wanted to start a new thread about the inner workings of the main vine.
I have always viewed it as a garden hose. when I saw those splits, I thought my plant was done.
What I realise now is that the main is not really like a garden hose at all. I am assuming that at each leaf node the main is plugged up. I am assuming that it is only hollow in-between the nodes. unlike a garden hose that is hollow from start to finish.
Hopefully, I am not sounding like a complete idiot at this point.
What exactly is the function of the hollow part of the main vine?
Can anyone explain to me exactly how the main vine works?

7/19/2011 9:27:58 PM

milford, CT,

Wally..good post!!! I always assumed the hollows acted like arteries and veins of a vascular system. The secondaries interconnect with the main and act together to drive the metabolism of the plant. Therefore when the vascular system is compromised by disease weight gains slow down...Someone else chime in and add to this because I am just going by what I have seen when I have cut vines.I have also observed that if you cut a vine in midday..very little liquid comes out...If you cut it at sunset...it will come out in a steady stream...fruit definetly grows mostly at night based on this observation. Mark

7/19/2011 10:44:15 PM

Germany

A very good reason for the tubular shape is stability. The plant has choice of two alternatives: 1) It grows a totally filled main, but this would either require production of twice the amount of plant mass (without any gain in green area for photosynthesis) or the plant would have to develop thin vines. 2) The plant produces a "capillary" (Yes, I know that "capillary" is an exaggeration for this thick system, but it works the same way). It needs less plant mass for building a big system of high stability. The flow of water and nutrients is in the walls, hence this tube does not need to be real tube from the beginning to the end. The plugs at the nodes add stability, mechanical as they prevent compression of the tube by the heavy leaves, and health stability by intersecting areas where diseases could develop and spread, thus limiting the rate at which diseases could spread within the plant. I´m not sure but it might well be that the tube might also act as a water reservoir for bad times. At least the leaf stalks (which are also "capillaries", for stability reasons...just imagine the power of wind which attacks the large leaf area, quite enormous forces, and the stalks won´t break so easily) are used to collect some water...you will notice that occasionally when removing a healthy leaf. Hope these few lines provide at least some explanation for this "plugged tube" phenomenon.

7/20/2011 1:13:57 AM

Germany

PS: In line two "understatement" would be a much better expression rather than "exaggeration". Just noticed that after posting my comments.

7/20/2011 1:16:34 AM