Sweet cassava yield gaps and key management factors in Brazil

Abstract The objective in this study was to identify yield gaps and management factors that limit the yield of cassava ( Manihot esculenta Crantz) in tropical and subtropical regions of Brazil. A total of 303 cassava fields were analyzed, and the yield potential was estimated using the Food and Agriculture Organization of the United Nations (FAO) model for agroecological zones for tropical regions and the Simanihot model for subtropical regions. Yield‐limiting management factors were identified using regression tree analysis, and the optimal values of the key variables were determined using threshold functions (boundary). The estimated yield gap was 34.2 Mg ha −1 in tropical regions and 27.7 Mg ha −1 in subtropical regions. In the tropical regions, the most limiting factors were planting density, planting date, land tenure, and irrigation. In the subtropical regions, planting density, planting date, row spacing, and desiccation were the most important constraints. Optimal values for planting density were 13,000 plants ha −1 for tropical and 11,000 plants ha −1 for subtropical regions. The recommended planting dates to achieve maximum yields were by November 15 in tropical areas and by September 27 in subtropical areas. These results show the importance of adapting cultivation practices to regional conditions in order to close yield gaps and improve cassava yields in Brazil.