EFFECT OF NITROGEN AND SULFUR APPLICATIONS ON POT CHRYSANTHEMUM PRODUCTION AND POSTHARVEST PERFORMANCE. I. LEAF NITROGEN AND SULFUR CONCENTRATIONS

Abstract

Chrysanthemums are one of the most important flowering plants produced internationally year round. The objectives of this research were to evaluate the effects of reducing nitrogen (N) applications by adding sulfur (S) and to determine if N* S interactions occur during the production and postharvest longevity of pot chrysanthemums. Pot chrysanthemum ‘White Diamond’ was grown in a peat-based medium following a typical production schedule except for fertilization. Plants received N at 50, 100, 150, or 200 mg L⁻¹ in combination with S at 0, 5, 10, 20, or 80 mg L⁻¹. Variablesevaluated were leaf N and S concentrations, plant height, leaf area, days to bud set, and first flower color and inflorescence anthesis as well as size and longevity under simulated interior conditions. In this article, leaf N and S concentrations are the variables discussed. In general, N* S interactions were significant for leaf S, but not leaf N concentration. Applications of 50 mg N L⁻¹ resulted in poor leaf N and S concentration and plants of questionable quality. Nitrogen applied at 100, 150, or 200 mg L⁻¹ in combination with at least 10 mg S L⁻¹ had acceptable leaf N concentrations and produced plants of commercial quality. Thus, N applications can be reduced by half when S is applied during commercial production.

ACKNOWLEDGMENTS

The authors gratefully acknowledge financial assistance from the LASPAU Fulbright Program for Oswaldo Macz, a grant from the Ohio Floriculture Foundation, and Yoder Bros. Inc. for cuttings and shipping costs. This article is submitted as Nebraska Agriculture Research Division journal series No. 12770.