Response of Sugarcane Cultivars to Chemical Ripeners During the Mid-Period of Harvesting in Ethiopia

Abstract

The relatively high temperature at Kessem sugarcane plantation in Ethiopia was hypothesized to justify the implementation of chemical ripeners as a strategic intervention to combat poor cane quality. Accordingly, a field experiment was carried out to assess the responsiveness of four sugarcane varieties (B52-298, NCo334, C86-12, and SP70-1284) to five ripener treatments: 2-chloroethylphosphonic acid (Ethephon™, 480 g ai L⁻¹) at 720 g ai ha⁻¹, fluazifop-p-butyl (Fusilade Forte™, 150 g ai L⁻¹) at 25.6 g ai ha⁻¹, trinexapac-ethyl (Moddus™, 250 g ai L⁻¹) at 250 g ai ha⁻¹, 2-chloroethylphosphonic acid + fluazifop-p-butyl combination at the mentioned application rates, trinexapac-ethyl + fluazifop-p-butyl combination at the mentioned application rates, and an untreated control. The experiment was conducted in a factorial arrangement in a randomized complete block design (RCBD) with three replications. The results showed that stalk height, stalk weight, sucrose content (%), and sucrose yield (t ha⁻¹) were affected by the main effect of ripener treatment, but there was no significant cultivar x ripener treatment interaction for the parameters collected. Overall, the sequential application treatment of trinexapac-ethyl followed by fluazifop-p-butyl 28 days later performed the best and improved sucrose content and sucrose yield by 2.64% unit and 2.15 t ha⁻¹, respectively. In economic terms, the trinexapac-ethyl + fluazifop-p-butyl sequential application treatment resulted in a marginal rate of return of 2393%. Therefore, the sequential trinexapac-ethyl + fluazifop-p-butyl ripener program was identified as a promising ripening strategy to be evaluated on a commercial scale at the sugarcane plantations in Ethiopia.