Characterization of nutrient disorders of ornamental Brassica oleracea 'Red Bor'

P. Cockson, B.E. Whipker
To produce ornamental kale (Brassica oleracea ‘Red Bor’), growers must be equipped with cultural information, including the ability to recognize and characterize nutrient disorders. Diagnostic criteria for nutrient disorders of ornamental kale species are absent from the current literature. Therefore, B. oleracea ‘Red Bor’ plants were grown in silica-sand culture to induce, characterize, and photograph symptoms of nutritional disorders. Plants received a complete modified Hoagland's all-nitrate solution of (macronutrient concentrations in mM) consisting of (macronutrient concentrations in mM) 15 nitrate-nitrogen (NO3), 1.0 phosphate-phosphorus (H2PO4), 6.0 potassium (K+), 5.0 calcium (Ca2+), 2.0 magnesium (Mg2+), and 2.0 sulfate-sulfur (SO42-) plus (micronutrient concentrations in μM) 72 iron (Fe2+), 18 manganese (Mn2+), 3 copper (Cu2+), 3 zinc (Zn2+), 45 boron (BO33-), and 0.1 molybdenum (MoO42-). Nutrient-deficient treatments were induced with a complete nutrient formula minus a single nutrient. Boron (B) toxicity was induced by increasing the element 10-fold higher than the complete nutrient formula. Plants were monitored daily to document and photograph sequential series of symptoms as they developed. Typical symptomology of nutrient disorders and critical tissue concentrations are presented. Out of 13 treatments, ten exhibited symptomologies; copper (Cu), molybdenum (Mo), and zinc (Zn) remained asymptomatic. Symptoms of nitrogen (N) and phosphorus (P) deficiency, plus boron toxicity (+B), manifested first, followed closely by iron (Fe) and sulfur (S) deficiencies. These disorders may be more likely problems encountered by growers and therefore plants should be monitored closely for these deficiencies.
Cockson, P. and Whipker, B.E. (2021). Characterization of nutrient disorders of ornamental Brassica oleracea 'Red Bor'. Acta Hortic. 1305, 423-430
DOI: 10.17660/ActaHortic.2021.1305.55
kale, toxicity, deficiency, macronutrients, micronutrients, fertility

Acta Horticulturae