THE EFFECT OF ALTERING NITROGEN AND SULFUR SUPPLY ON THE GROWTH OF CUT CHRYSANTHEMUMS

'Dark Yellow Fuji Mefo' chrysanthemums (Dendranthema grandiflora Tzvel ev.) were grown hydroponically with either 64, 127, or 254 mg . L-1 N and either 0, 1, 2, 4, 8, 16, 32, or 64 mg . L-1 S in a randomized com plete block. Time to flower was measured and symptoms of S deficiency were observed on root, stem, and leaf systems. New leaves and inflores cences were analyzed for S, and lower leaves were analyzed for N conce ntration. There mere four sampling dates and two experiments. Flower d iameter was measured when flowers mere present, while stem length was measured every sampling date. Nitrogen application could be reduced by half to 127 mg . L-1 as long as some 8, 4 mg . L-1 in the fall and 8 mg . L-1 in the spring, was applied. Sulfur deficiency symptoms observ ed included branchless roots, which aged earlier, overall yellowing of new leaves, and reddening on the leaf abaxial starting from older lea ves and moving acropetally. Plants receiving no S had smaller leaves, shorter stems, delayed inflorescence initiation, and restricted inflor escence development. Without S, plants did not produce flowers suitabl e for commercial sale.