Nitrogen Source and Concentration, Growing Medium, and Cultivar Affect Longevity of Potted Chrysanthemums

Abstract

Chrysanthemums `Bright Golden Anne' and `Iridon' [Dendranthemum ×grandiflorum (Ramat.) Kitamura] were grown with N concentrations of 1.3, 2.6, or 5.2 kg N/m' of water during the crop cycle from either Osmocote slow-release 14N-6.2P-11.6K or 12.4N4.4P-14.lK or Peters soluble 20N-4.4P-16.6K. Plants were moved to simulated interior rooms at flowering to evaluate effects of the treatments on longevity. `Bright Golden Anne' longevity was not affected by fertilizer source, but `Iridon' longevity was reduced when Peters soluble fertilizer was applied at 2.6 and 5.2 kg N/m 3 of water, whereas N concentration did not affect longevity when the slow-release Osmocote fertilizer was used. In an additional study, `Tip', `Copper Hostess', and `Iridon' were grown in three soil media using 1.3, 2.6, or 5.2 kg N/m' of water using Peters soluble 20N-4.4P-16.6K fertilizer from time of planting until flowering. Longevity increased as N concentration decreased when chrysanthemums were grown in Metro Mix 350, whereas N concentration had no significant effect on chrysanthemums grown in Vergro Klay Mix or a peat-perlite-sand mix. `Tip' showed significant in. creases in longevity as N concentration decreased.