It is a solution to the problem created by the wind: it has a tendency to fit through the holes in the nylon and create a "balloon effect" causing various adverse effects including some damage to the plant.
In addition, as you can see, you decrease the effectiveness of nylon in all senses!
To remedy this I thought this simple and non-expensive construction.
Step 1: The components
In an early version appears in the video, I filled with sand pipe before connecting it to make a circle; in the second version, which is the one that I adopted as final I did go into the inside of the tube a segment of wire of 2 mm diameter, then fillet with bamboo rod, causing him to go through this after having drilled a hole;
In this way it was possible, by sticking the barrel that also serves as a mentor for the tomato that I planted in the ground, setting circles are also kept in position by wire fixed to the barrel.