Differential yield and nutrients of Hibiscus sabdariffa L. genotypes when grown in urban production systems

Abstract

Urban agriculture is expanding but faces economic and environmental challenges. One way to mitigate the impact of climate change on food security in cities with a temperate climate is to grow crops adapted to the hotter temperatures expected by the middle of the twenty-first century. Hibiscus sabdariffa L., commonly called red sorrel or roselle, is a hardy shrub widely grown throughout tropical regions of the world that has high economic value as a food crop. Most studies on H. sabdariffa have been conducted in tropical areas and, to our knowledge, none compared genotypes, their nutrients, and suitability for urban production. Therefore, we grew seven genotypes of H. sabdariffa in three production systems (i.e., green roof, field row, high tunnel) in and near Washington, DC to: 1) determine differences in leaf and flower yield between genotypes and production systems; 2) determine nutritional differences of leaves between genotypes and production systems; and 3) determine susceptibility of genotypes to insect pests. Genotype PI 286316 produced copious flowers, especially in the high tunnel. Production of leaves was highest in the field row, despite this system being most frequently attacked by Popillia japonica Newman. PI 273388, PI 275414, and green hibiscus produced the highest mass of leaves. Most minerals were influenced by the production systems, but most notable is that genotypes differed in amounts of some nutrients regardless of the production system. The locally adapted green hibiscus, which was cultivated in the Washington, DC area for many years, produced a moderate number of flowers, was a top producer of leaves in all systems, was least attacked by P. japonica, and had higher levels of nutrients than some other genotypes. Overall, our work demonstrates that H. sabdariffa, a tropical plant, can be grown in temperate, urban systems.