You can pinch in different ways, it depends on varietal characteristics, growing conditions (vertical culture or grown) Usually it bears fruit on the shoots 2-3 orders of magnitude (depends on the variety) If you grow seedlings, you can start forming at home, after 3-4 leaves pinch the top. The plant will immediately give lateral shoots. If you grow in a vertical culture, then leave 1-2 shoots, tie them up. On them, lateral shoots are formed again - Remove the sterile ones, and on which there are female flowers (with an embryo of the fruit), pollinate yourself. The fruit will be tied, it will begin to increase in size, pinch the lash with the fruit, leaving 2-4 leaves after the fruit. How much fruit to leave? I repeat, this is individual for each variety, there are varieties with high energy of growth, there are small fruited ones, etc. Pinch the main lash when it reaches the trellis, so that the plant does not spend food on the growth of green mass, and all the nutrition goes on the growth of fruits. If you grow in a grown, then pinch the main lash over the 4th sheet, the overgrown side lashes again over the 3-4 sheet, determine how many fruits to leave and pinch leaving 2-4 leaves after the fruit. Fertilizing with nitrogen fertilizers only in the initial period of growth, then phosphorus-potash. The amount of fertilizer in grams, as they say in all the manuals on vegetable growing, I can’t say so. The soil on each plot is different, and accordingly the number of fertilizers is an individual matter. In no case do not cut the side shoots at a height as you write 100cm. This rule is good for cucumbers (blinded-plucked shoots growing from the sinuses of the 3-4 lower leaves) this is done so that the fruits are distributed throughout the stem, and if you leave the lower fruits, then all the nutrition will go to them and the fruits above will be bad tie up.
grew melons for the first time this year. Sowing seedlings on May 1 or a little earlier, planting in the greenhouse on the 20th, 2 roots per hole. I made the first pinch over 3 sheets, left 3 lashes (this was a mistake, you need to leave 2). I also want to try watering with a buried bottle with a cut off bottom - melons do not like getting on a barrel of water. Of the varieties with names, “Kolkhoznitsa” and “Honeycombs” showed themselves best.