High wire vegetable cropping has become a common plant training technique in greenhouses for growing indeterminates
There seems to be a worldwide trend to use high wire cropping to grow indeterminate seeds in greenhouses: these plants are trained vertically on a string or raffia twine (either synthetic or made out of natural fibers). This twine is unrolled from a spool or TENAX metal tutoring hook, and as the plant grows it is gently pushed along the the top wire of the greenhouse (or any other cable or rigid piece of the structure) as to allow the growing plant to fully extend itself.
The indeterminate tomato, pepper or cucumber plant is twisted along the twine and every so many days the TENAX tutoring hook is allowed to release a few more inches of cord. High wire vegetable crops in a sense compete with trellising net but HORTOMALLAS netting allows the plant to develop fully at 360 degrees rather than just along the twine. Both methods though may require a HORTOCLIPS tomato ring.
Problems with tutoring plants using the high wire cropping system
One of the mayor counter indications of training your greenhouse plants on a high wire is the mechanical spreading of phytopathogens. Instead of letting plants grow naturally on a crop net like in the case of cucumbers (which tendrils are quite capable of pulling and sustaining the plant without any external agents like workers or clips) or as in the case of the double wall of net for tomatoes so the branches can simply lean on the meshes, the Tenax hook method, requires a lot more labor.
Labor, besides increasing operating costs, increases the probability of contagions, as the workers hands and clothes could have come in contact with a sick plant inside the greenhouse or even bring bacteria and viruses from the outside, no matter how good your sanitary prophylaxis is, washing hands and shoes soles before entering, spraying clothes, or even wearing jumper suits, or washing hands in milk to neutralize any virus, could end up being a futile preventive measure compared to the ease of using netting.