b'Excess symptomsAn excess of calcium in the root environment can lead to phytotoxicity. Stains from calcium salts can form around the sepals. This can be aggravated by high humidity and extra calcium fertilization.SulphurThe need for sulphur is low but very important for all kinds of processes. Sulphur is offered as a fertilizer in the form of sulphate. Sulphate is actively absorbed in the root and converted into sulphide by enzymes in the root and chlorophyl granules. Then it is built into a large number of amino acids (methionine) that are the building blocks of proteins, vitamins and antioxidants. Some proteins protect the plant against environmental stress and pests.At high levels of sulphite or hydrogen sulphide in the air, the plant can absorb this via the leaf. Very high values are again phytotoxic.Deficiency symptomsA lack of sulphate first manifests itself in the youngest leaves and quickly turns from light green to yellow. The leaves that grow out are also smaller than normal and the plant is compact. If the shortage continues, the older leaves will also turn yellow. The leaf can also deform and produce fewer sprouts. If the sulphate fertilization is too low and there are no visible symptoms, there may still be a loss of yield. Excess symptomsExcess sulphate is rarely, or never, found.Lack of calcium117'