Advancing cane-quality management in the South African smallholder-farmer sector through participatory on-farm demonstration and knowledge exchange

Cane-quality management involving chemical ripening is an important component of profitable sugarcane production by large-scale commercial farmers in South Africa. For smallholder farmers (SHFs), however, sugarcane field size and adjacent alternative land-uses render conventional aerial crop-spraying methods unsuitable. The recent availability of spraying drones has created opportunities for chemical ripening to be introduced to the smallholder farmer sector. A network of demonstration trials based on strong partnerships of researchers, extension specialists and smallholder farmers, and participation by various industry stakeholders was established in 11 smallholder farmer regions. Knowledge exchange in each region involved an initial stakeholder engagement workshop, a series of practical field days during the execution of the trial, and post-trial information sharing events. The initial workshops were aimed at creating project awareness, defining the relative advantage that ripening with drones could deliver, identifying negative perceptions and potential barriers that might hinder adoption, and reaching consensus on trial methodology. Field days were focused on demonstrating the processes of maturity assessment to establish the need for chemical ripening and applying a ripener with a drone to parts of the fields. At the same time, control portions were left untreated, and assessing the efficacy of ripening benefits and harvest readiness. These demonstrations illustrated the judicious use of agrochemicals by only spraying fields suited to ripening. In-field estimates of cane yield and cane quality in the ripened and control treatments shortly before harvest, and in some cases, field production data from the sugar factories, revealed a range of improvements in recoverable crystal (ERC) due to ripening that was influenced by location and sugarcane cultivar. Although the SHFs expressed genuine interest in chemically ripening their crops with spraying drones, industry challenges will need to be addressed prior to wider adoption.