VIEW ARTICLE

Influence of Calcium Nutrition on Bacterial Canker of Resistant and Susceptible Lycopersicon spp.. R. L. Forster, Graduate Research Assistant, Department of Plant Pathology, North Carolina State University, Raleigh, 27607; E. Echandi, Professor, Department of Plant Pathology, North Carolina State University, Raleigh, 27607. Phytopathology 65:84-85. DOI: 10.1094/Phyto-65-84.

Bacterial canker-resistant Lycopersicon hirsutum (P.I. 251305), L. esculentum (P.I. 340905), and L. esculentum × L. pimpinellifolium ‘MR 4’ and ‘Bulgaria 12’, and susceptible L. esculentum (‘Manapal’) and L. peruvianum (P.I. 251306) were grown from seed in a phytotron. Transplanted seedlings received nutrient solutions containing 55, 150, and 300 µg/ml calcium, respectively. Five-week-old plants were inoculated by stabbing the stem above the cotyledonary node with a dental root canal file dipped in a Corynebacterium michiganense suspension containing 10⁷ cells/ml. Disease severity was inversely correlated with the concentration of calcium in the nutrient solution and in petiole and stem tissue. The (Ca + Mg)/(Na + K) ratio was negatively correlated with disease rating of individual plants.