How many seeds do we need and why?

saber fazer em serralveslinho em serralveslinhoTêxtilEN

29/06

Densidade da sementeira conforme aconselhada pela Maria das Dores. / Flax sowing density as advised by Maria das Dores. — Flax sowing density as advised by Maria das Dores.

Comparação de 2 caules: um localizado no meio do talhão (o mais fino), onde a distribuição é mais densa, e outro de uma planta cuja semente "caiu" fora do talhão e cresceu sem outras plantas à volta. / Comparing two stems: one from a plant loca… — Comparing two stems: one from a plant located in the middle of the field (the thinner one), where the distribution is denser, and another from a seed who fell outside the field.

I think the question I tried hardest to find a clear answer to from the people I consulted and the material I read was the exact amount of seeds I would need for a given area.
At first, before studying the subject in more depth, I didn't understand the disparity in the answers. It wasn't until I started reading about the influence of sowing density on the development of flax plants and, consequently, on the quality of the fibre they produce that I understood the issue.

If sowing is carried out at a low density, the plant will branch out more and produce thicker stems, which is fine if you want to produce seed, but will result in thicker fiber and a high percentage of tow. To obtain a fine, delicate fiber, you need to sow densely, forcing the plants to grow vertically, without branching and keeping the stems thin.
In the second image above, I compare the stem of one of the plants in the middle of the plot, in a very dense area, with another stem of one that, having fallen outside the plot, had fewer plants around it. As you can clearly see, the second one is two or three times thicker than the first.

Eng.Silva referred me to the studies and books written by Eng.Flávio Martins, who advises the following in one of his books:

“Sowing is done using from 160 to 200 and more kilos per hectare.” And in another book of his, he says “A good density of plants contains around 2000 per square meter.” Of course, within these indications there is a certain relativity, as we have already realized that it varies slightly according to the fineness of the flax we want to produce, and this can even be an option.

So, to sow flax for textile purposes, we can spend approximately 16 to 20gr of seeds per square meter, with some advising up to 25gr/m2.

[This post refers to the research and activities developed as part of the Saber Fazer program at Serralves ]

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