Evaluation of calibrachoa cultivars for black root rot resistance, 2019.
Plant Disease Management Reports
By Lindsey E. Becker; Marc A. Cubeta in Extension
March 9, 2019
Figure. Mean disease severity of seven Calibrachoa cultivars after harvest.
Abstract
Five cultivars of calibrachoa were evaluated for resistance against six isolates of Thielaviopsis basicola (Tb), causal agent of black root rot. Isolates of Tb were sourced from calibrachoa, lettuce, pansy, and viola. Standardized inoculations were carried out in a greenhouse setting, with plants inoculated at transplanting. All cultivars exhibited symptoms of black root rot which includes stunting, chlorosis, and wilting. While all cultivars were susceptible, some cultivars exhibited higher disease ratings than others. Variation in susceptibility of individual cultivars was also observed by Tb isolate.