Hi Moshe and welcome to GoY. Not sure exactly what you are asking here. When you are growing tomatoes you feed them with a liquid tomato food once a week after the first truss of fruit has started to form.

It's also a good food to use to water (diluted) on your containers of flowering plants. I use it to feed my Clematis, as well. I 'think' it's potassium that it contains - but could be wrong on that one. It's to promote more flowers, anyway.

tnx.
Where can i find the ingredient of that "liquid tomato food"
moshe

You buy a bottle of it not one ingredient, you need the complete fertiliser which contains Nitrogen, Phosphorous and Potash (Potassium) - the later is what helps the tomato plants to set fruit. Where you would buy in Israel I don't know.

We normally buy it as a concentrated liquid from the garden center.The main advantage is that it is relatively low in nitrogen, which produces lush leaves, but higher in the minerals that produce strong roots, flowers and fruits. We use it a lot on bulbs growing in pots.

I've just looked - and it's high in potash plus seaweed extract. Read what Moongrower and Bulbaholic say - they're right! :-)))