Evaluation of Chemical and Biological Products for Control of Crown Gall on Rose

Crown gall is a soil-borne bacterial disease caused by Agrobacterium tumefaciens, leading to significant economic losses in many plant species. For the assessment of the biological and chemical products on crown gall, each plant's crown region and roots were wounded, and then were dipped into their respective treatments. After the treatments, the plants were inoculated with a suspension of pathogenic A. tumefaciens isolate FBG1034 and maintained in a greenhouse for six months to assess them for gall formation. A quantitative real-time PCR assay was performed to quantify the A. tumefaciens using the chvE gene. Biological products such as the Agrobacterium radiobacter strain K1026, and strains 1 and 2, resulted in the lowest average root gall diameter and significantly reduced the crown gall diameter to stem diameter ratio, and the chemical product copper octanoate reduced the number of crown and root galls as well as the crown and root gall diameter compared to the inoculated, non-treated control. Moreover, both the A. radiobacter strain K1026 and strain 1 treatments resulted in an approximately 85% and 65% reduction in crown and root gall incidence, respectively, in both of the trials compared to the inoculated, non-treated plants. The findings of this study indicate that the use of biological and chemical products could help to suppress crown and root gall disease in rose plants.