REFEREED PAPER REVIEW OF FORECASTS OF SEASONAL AVERAGE CANE QUALITY FOR SOUTH AFRICAN SUGAR MILLS SINGELS A 1 , PEACOCK SD 2 , NAIDOO G 3 , PARASKEVOPOULOS A 1 , SCHORN PM 2 AND GABRIEL AB 4 1,2 South African Sugarcane Research Institute, P/Bag X02, Mount Edgecombe, 4300, South Africa 2 Tongaat Hulett Sugar Limited, P/Bag 3, Glenashley, 4022, South Africa 3 Cane Testing Service, South African Sugar Association, Flanders Drive, Mount Edgecombe, 4300, South Africa 4 South African Cane Growers’ Association, Flanders Drive, Mount Edgecombe, 4300, South Africa abraham.singels@sugar.org.za Abstract The South African (SA) sugar industry uses Recoverable Value (RV) as a measure of cane quality for cane payment purposes. The RV content of cane stalks (RV%cane) is determined primarily by its sucrose content, fibre content and non-sucrose content. Forecasts of seasonal average RV%cane for each mill are needed to determine monthly payments to growers. These forecasts need to be accurate to minimise payment corrections during and at the end of the milling season. Monthly forecasts are therefore issued from April to the last month of the milling season by mill group boards (MGB) and by the Seasonal RV%cane Forecasting Committee (RVFC) of the South African Sugar Association (SASA). Forecasts are derived from historical and current to-date cane crush and quality data, current and expected growing conditions, prevalence of pests and diseases, conditions that effect harvesting and transport operations, mill performance and expected length of the milling season. The forecast errors (defined as the difference between the forecast value and the actual value achieved at the end of the season) of MGB and RVFC RV%cane forecasts from 2004 to 2011 were compared with those of two methods based on the to-date RV%cane anomaly. In the majority of cases, RVFC forecasts were more accurate than MGB forecasts up to about August. A method based on the to-date RV%cane anomaly that also accounts for expected agro-climatic conditions performed better than both these methods in 11 out of 14 cases, from May (when delivery data becomes available) to about August and could be used to improve the accuracy of RV%cane forecasts for the SA sugar industry. It is recommended that the RVFC of SASA incorporate the key elements of the TDRV methods into its forecasting procedures. Keywords: Recoverable Value, forecast error, cane payment, climate, milling season Introduction The South African (SA) sugar industry uses Recoverable Value (RV) as a measure of cane quality for cane payment purposes. The RV content of cane stalks (RV%cane) is determined primarily by its sucrose content, fibre content and non-sucrose content. Sucrose content, and hence RV%cane, typically increases through the milling season, reaches a peak and then declines towards the end of the season, due mainly to climatic factors (rainfall and Singels A et al Proc S Afr Sug Technol Ass (2012) 85: 54 - 66 54