DD Henriquez, JV Diaz, C Ghio, DD Costilla, AC Diaz Romero, P Medina, MF Figueroa and S Ostengo
Estación Experimental Agroindustrial Obispo Colombres (EEAOC), Las Talitas, Tucumán, R. Argentina; dhenriquez@eeaoc.org.ar
The focus of the Sugarcane Breeding Program of the Estación Experimental Agroindustrial Obispo Colombres (SCBP-EEAOC) is to develop new TUC varieties with high cane yield and sucrose content, early maturity and good phytosanitary behavior, among other industrial and agronomic aspects. From 2020/2021 season, sugarcane smut (Sporisorium scitamineum) increased in prevalence in Tucumán, Argentina, becoming one of the main sugarcane diseases in the region. The aim of this work was to examine the impact of smut in the first and second clonal stages and infield variety trials of the selection process of the SCBP-EEAOC during the last decade. Natural infection is used to screen and select for smut resistance clones over five crossing series during the first (stage II) and second (stage III), clonal stages and the infield variety trials stage (penultimate selection stage). In all crossing series, 0.26% of clones were discarded in the first and second clonal stages due to their susceptibility; these stages were conducted between the 2014 and 2019 seasons, with low smut pressure. During the infield variety trials stage, 17.50% of clones showed a susceptible reaction to smut; this stage was evaluated between the 2019 and 2024 seasons under high-smut pressure. The results show that the increase in smut prevalence observed in Tucumán during the last four seasons resulted in the discarding of a high number of clones in the infield variety trials that were not identified as susceptible in early stages. This highlights the need for artificial inoculation tools to assess smut resistance in early stages, overcoming the lack of fungal pressure or favorable conditions for the disease.