Trends and progress in sorghum research over two decades, and implications for global food security

Sorghum is a climate-resilient crop critical to livelihood in several semi-arid regions but has traditionally received limited research investment. In depth bibliometric analysis covering years 2000 – 2020 was performed using Scopus database to gain insight on sorghum research trends and identify gaps and opportunities for the crop. 17,720 relevant documents were retrieved and analysed. Robust increase in research literature on sorghum was observed for the period, more than tripling to almost 1,600/year in 2020. New opportunities stimulated by the sorghum genome sequencing and evolution of the crop as a model for drought tolerance, and growing recognition of sorghum as a potential food and energy security crop in response to climate change were key drivers of research output. Encouraging evidence demonstrates that both sorghum yield and nutritional quality are more stable to climate change compared to major cereal crops like maize and rice. End use trends suggest sorghum is more competitive in the food market than feed and bioenergy markets that have dominated its production in the past. Quality traits identified as most likely to expand long-term sorghum food value chain include endosperm functionality (kafirin protein properties), health (resistant starch and polyphenols), and nutrition (iron and zinc). Gene editing technology has shown promise as a tool to efficiently design sorghums with traits for high value food applications. Increased investment in market-driven sorghum improvement research targeting traits that address long-term consumer food needs will benefit both global food security and the environment.