Phoma Leaf Spot Susceptibility and Horticultural Characteristics of Table Beet Cultivars in New York

Abstract

Phoma leaf spot (PLS), caused by Phoma betae (syn. Neocamarosporium betae), is an important fungal disease affecting table beet (Beta vulgaris L. subsp. vulgaris) production in New York. PLS lesions on the foliage can lead to rejection in fresh market sales and can reduce leaf integrity, which can disrupt mechanized harvesting. Eight popular table beet cultivars were assessed for susceptibility to PLS using P. betae isolates representative of the New York population in two small-plot, replicated field trials in Geneva and Freeville, NY. There were significant differences in PLS incidence, severity, and epidemic progress (as measured by area under the disease progress stairs) and horticultural characteristics among cultivars. Non-red table beet cultivars (Avalanche, Boldor, and Chioggia Guardsmark) were less susceptible to PLS than red cultivars (Falcon, Merlin, Rhonda, Red Ace, and Ruby Queen). Significant differences in fresh weight of roots and dry weight of foliage were detected between cultivars at harvest (86 days after planting [DAP] in Freeville and 91 DAP in Geneva). Falcon had significantly higher root weight than Boldor, and Ruby Queen produced significantly more foliage than Boldor. Information on the performance of these cultivars provides locally valuable information for cultivar selection in a broad range of markets.