L Gañán-Betancur, EA Rincón, JC Ángel and JJ Riascos
Cenicaña, Calle 58N # 3BN-110, Cali, Colombia; lganan@cenicana.org
Breeding for resistance to sugarcane smut, caused by Sporisorium scitamineum, has been a priority for the Varieties program at CENICAÑA. Smut had an economic impact in the susceptible variety CP 57-603 in the late 1980s, but for a long time there were no concerns about smut in the Colombian sugarcane industry in the Cauca River Valley (CRV). This work monitored the distribution and intensity of smut across the CRV in the sugarcane variety CC 11-595, which up to 2024, occupied about 7% of the total sugarcane area established in the region, and determined whether the pathogen inoculum from CC 11-595 could affect the resistance of commercially established varieties in the region. The results of thorough monitoring from 2023 to 2024 showed that the mean incidence of smut in fields planted to CC 11-595 increased from 0.4% in the first semester of 2023 to 2.7% in the second semester of 2024, in which the disease was observed in 70.5% of the sites evaluated. Given the increase in the prevalence, ongoing research activities are in place to keep monitoring the advance of smut in the region, as well as to provide alternatives to growers for better management of the disease in nurseries and commercial fields. The disease was not seen on any of the major sugarcane varieties grown across the CRV, and these varieties showed a resistant response to smut when exposed to S. scitamineum inoculum from the variety CC 11-595.