Calyx splitting and high percentage of stem brittle was observed in the carnation (Dianthus caryophyllus L.), cv. Standard White Candy, grown under fertigation on a sandy loam soil, in the coastal plateau of Israel, 18 km east from the Mediterranean coast. The hypothesis was tested that the incidence of this disorder could be reduced by raising the potassium (K) concentration in the plant by increasing K and the NNO3: N-NH4 ratio in the fertigation medium. The increase in K levels in the fertigation media was reflected in the content of K in the plant dry matter(DM). The beneficial effects of the KNO3 treatment probably resulted because of the absence of N-NH4 in the fertigation media. These beneficial effects were expressed in the form of a17 per cent increase in flower yield and a minimizing of calyx splitting.
