J Appl Microbiol. 2022 Jun 18. doi: 10.1111/jam.15671. Online ahead of print.
AIMS: To examine the interaction of diagnostic techniques, initial titers of Leifsonia xyli subsp. xyli (Lxx), sugarcane genotype, and thermotherapy on ratoon stunt (RSD) control.
METHODS AND RESULTS: Single buds of RB867515, RB92579, and RB966928 submitted to 50°C/2h or 52°C/30min under factorial block design and five replications; results checked nine months later by serological (DBI) and molecular (PCR) techniques. A 10,000 bootstrapping simulation were performed to infer best plot size based on the experimental coefficient of variation. Analysis of variance showed significance only on initial Lxx titers and RSD-control. Despite absence of significance in the overall analysis, minor differences in control success with different methods and cultivars is predicted to have a major epidemiological impact on RSD considering successive harvests and vegetative increase. According to an epidemiological interpretation, the 50°C/2h treatment was more effective, cultivar RB966928, the most susceptible, and the PCR-based method was most the sensitive for pathogen detection. The minimum required plants per plot was 15, indicating high precision of our experiment.
CONCLUSIONS: Data interpretation considered both the statistics analysis and the epidemiology aspect of RSD in order to improve RSD management. The Brazilian sugarcane industry will benefit from this approach since it is not using it.
SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first study that examined multiples factors that affect RSD control. Our work pinpointed the importance of the thermotherapy, its best combination as well as the diagnostic test. Also, the effect of the cultivar to respond to management strategies. Because the epidemiological aspect of RSD was taking into consideration, results of our work can have an impact on RSD control in the field.