Current Situation and Research Gaps on Cassava Witches’ Broom (Rhizoctonia theobromae)

Abstract

Cassava Witches’ Broom Disease (CWBD), associated with species of Rhizoctonia theobromae, is an emerging plant disease of high phytosanitary concern, recently reported in several Southeast Asian countries and, more recently, in Brazil. The emergence and rapid spread of this disease pose a significant threat to cassava productivity and food security in tropical regions. This study aims to compile and analyze the main scientific evidence published between 2018 and 2025 regarding the etiology, dissemination, socioeconomic impact, and management strategies of CWBD. The methodology followed a systematic review based on the PRISMA protocol, including recent national and international publications. Results indicate that CWBD severely affects cassava growth and yield, directly impacting the livelihood and socioeconomic stability of smallholder farming communities. Current management strategies focus on preventive measures such as the use of pathogen-free planting material, crop rotation, and continuous phytosanitary monitoring. However, scientific gaps remain concerning the definitive identification of the causal agent, understanding of its life cycle, and the development of resistant genotypes. It is concluded that the spread of CWBD represents an increasing threat to tropical cassava production, requiring integrated efforts in research, surveillance, and public policy to reduce its impacts.