Wpływ różnych dawek fosforu oraz dodatkowego nawożenia wapniem lub potasem na plonowanie pmidorów w uprawie hydroponicznej wrocławskiej przy dwóch intensywnościach naświetlania [The influence of various doses of phosphorus and of the addition of calcium or potassium fertilization upon the yield of tomatoes in Wrocław hydroponic culture using two intensities of light]

Two experiments were carried out with phosphate fertilization of tomatoes in hydroponic culture. It has been proved that an additional dose of phosphorus given during the second cluster bloom, caused an yield increase. The optimal dose is 12 g of superphosphate (16% P2O5) per plant. The "green back" symptoms did not appear in these conditions. The parallel additional applying of calcium or potassium gave a decrease of the yield. When the light intensity was lowered to about 50%, the yield has decreased by half. In these conditions an additional applying of calcium (0,4 g CaCO3) and phosphorus (1g superphosphate) annulated the negative influence of the low light intensity