The Dynamics of Sugarcane and Sugar Yields in Florida: 1950-2018

Florida is the largest producer of sugarcane (Saccharum spp.) in the United States. Since 1911, the University of Florida continues to develop new sugarcane cultivars that are better adapted to the Florida environment. We use piecewise regression to determine the growth in both Florida sugarcane and sugar yields, and how new sugarcane cultivars have positively affected yields. We use breakpoints for periods between 1950 and 2018: Scenario 1 (1950-2018), Scenario 2 (1950-1980 and 1981-2018), Scenario 3 (1950-1980, 1981-2000, and 2001-2018), and Scenario 4 (1950-1968, 1969-2000, and 2001-2018). In most scenarios, new sugarcane cultivars have significantly increased sugarcane and sugar yield, as well as sugar content. For 1950 to 2018, sugarcane yield increased by 21.3 Mg ha(-1) (30%, P < 0.01) and sugar yield increased by 5.1 Mg ha(-1) (78%, P < 0.01). Sugar content also increased significantly (P < 0.01). Before 1980, sugarcane yield significantly decreased (P < 0.05), whereas sugar yield showed neither a significant increase nor decrease. For 1980 to 2018, both sugarcane and sugar yields significantly increased (P < 0.01). Sugar yield decreased from 0.16 Mg ha(-1) yr(-1) for 1950 to 1980 to 0.10 Mg ha(-1) yr(-1) for 1981 to 2000. Sugarcane yield had the same rate of increase for 1980 to 2000 (0.66 Mg ha(-1) yr(-1)) and for 2001 to 2018 (0.69 Mg ha(-1) yr(-1)). There was neither a significant increase nor decrease in sugarcane and sugar yields before 1968. For 1969 to 2000, the increase in sugarcane yield (0.29 Mg ha(-1) yr(-1)) was less than the increase in sugar yield (0.09 Mg ha(-1) yr(-1)).