DD Henriquez, P Medina, DD Costilla, JV Diaz, NR Sorol and S Ostengo
Estación Experimental Agroindustrial Obispo Colombres (EEAOC), Las Talitas, Tucumán, Argentina: dhenriquez@eeaoc.org.ar
In Tucumán, Argentina’s primary sugarcane-producing province, frost events frequently affect optimal crop development, and sugar recovery during industrial processing. The entire sugarcane production area is prone to frost. Therefore, characterizing the TUC varieties (developed by the Sugarcane Breeding Program of the Estación Experimental Agroindustrial Obispo Colombres (SCBP-EEAOC)), in relation to frost-induced deterioration is crucial for optimizing cultivar management strategies. This study aimed to assess the post-frost deterioration response of the main TUC varieties: TUC 95-10, TUC 03-12, TUC 06-7, TUC 02-22, and TUC 00-65. During 2024, from 15 May to 17 October, samplings were conducted biweekly at two experimental sites, in order to understand the development of sucrose content during the harvest period prior to the first frost event and, subsequently, to quantify changes in sucrose concentration (%) following a severe frost event. The commercial cultivars LCP 85-384 and TUCCP 77-42 were included as reference controls, representing high and low tolerance to juice deterioration after frost, respectively. The samples, composed of 10 clean stalks trimmed at their breaking point, were processed in the Chemistry laboratory of the EEAOC. Sucrose concentration (g of sucrose per 100 g of juice) was quantified using high-performance liquid chromatography (HPLC). The first significant frost occurred on 11 July, with moderate intensity in Los Quemados (-3.5°C for 8 h) and severe intensity in Santa Ana (-4.2°C for 10 h). TUC 06-7 and TUC 03-12 exhibited a low initial rate of sucrose decrease at both sites, indicating notable stability in the early stages following the frost. TUC 95-10 showed an intermediate initial rate of sucrose decrease. In contrast, TUC 02-22 and TUC 00-65 experienced a higher initial rate of sucrose loss, although with performance superior to that of TUCCP 77-42, suggesting somewhat reduced performance in the early post-freeze stages. These preliminary results represent the first characterizations conducted on the behavior of TUC sugarcane varieties in response to frost, making it essential to continue with additional trials under severe frost conditions to validate these results.