Estimating Cassava Yield Potential and Assessing Yield Gaps in Rio Grande Do Sul State

Manihot esculenta Crantz (cassava) has been cultivated for over 8,000 years in Latin America, playing a vital role in traditional knowledge systems, cultural identity, and food security. Today, cassava remains a key staple crop, especially for smallholder farmers in developing regions. However, with the projected global population growth, increasing crop productivity has become essential. Despite Brazil being the fifth-largest cassava producer, its productivity remains relatively low. This study aimed to estimate the potential yield of cassava in Rio Grande do Sul (southern Brazil) and to identify and quantify existing yield gaps. The Global Yield Gap Atlas (GYGA) framework was applied, considering cultivated areas and climatic conditions across the state. Yield potentials were simulated using the SIMANIHOT model, and yield gaps were calculated based on productivity data from IBGE and regional farmers. Results showed that potential yields ranged from 49.2 to 62.2 Mg ha-1, with a state average of 54.7 Mg ha-1. The water-limited yield potential was 53.3 Mg ha-1, while yield gaps ranged from 66.3 to 79.3%. These gaps were mainly associated with suboptimal management practices and, to a lesser extent, water limitations. Overall, the findings suggest that cassava production in Rio Grande do Sul could be significantly increased within the current cultivated area by improving management practices such as varietal adaptation, fertilization (especially potassium), planting density, planting date, and weed control.