Soybean rust resistant and tolerant varieties identified through the Pan-African Trial Network

Authors: RAMPAZZO FAVORETTO, VITOR - University Of Illinois; MURITHI MUTHURI, HARUN - Oak Ridge Institute For Science And Education (ORISE); LELES, ERICA - University Of Illinois; DA FONSECA SANTOS, MICHELLE - University Of Illinois; CHIGEZA, GODFREY - International Institute Of Tropical Agriculture (IITA); GOLDSMITH, PETER - University Of Illinois; COYNE, DANIEL - International Institute Of Tropical Agriculture (IITA); Clough, Steven

Submitted to: Pest Management Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/13/2024
Publication Date: 1/30/2025
Citation: Rampazzo Favoretto, V., Murithi Muthuri, H., Leles, E., Da Fonseca Santos, M., Chigeza, G., Goldsmith, P., Coyne, D., Clough, S.J. 2025. Soybean rust resistant and tolerant varieties identified through the Pan-African Trial Network. Pest Management Science. Article 8639. https://doi.org/10.1002/ps.8639.

Interpretive Summary: The global demand for soybeans has increased by over 145% over the last 30 years and is projected to reach an additional 70-80 million metric tons over the next ten years. Sub-Saharan Africa soybean production is increasing by 6.8% per year compared to a worldwide increase of 4.7%, with small-scale producers accounting for most of the 1.5 million hectares grown in Africa. However, despite this massive expansion in production and demand, African producer yields are less than half of the global average yields. The yield gap is partly attributed to diseases and pests. A significant threat to soybean production is soybean rust, which causes yield losses of up to 90% globally. Proper soybean rust management relies on various factors, including host-resistance. However, information on the rust-resistance level of African varieties is limited. The Pan-African Trial network developed soybean variety trials in diverse African regions to address the yield gap by finding the most adapted varieties. One of the measures in these varieties’ screening trials is documenting differences in soybean disease infection levels when present in the field. This study aimed to classify soybean varieties screened by the Pan-African Trial network due to their rust-resistance level. Seven years of data (2015-2022) totaling 370 trials were considered for the analysis. From those trials, 98 varieties were classified according to their level of rust resistance. A total of 12 varieties were classified as tolerant to ASR across Africa through this framework, which can be utilized to address other disease issues with crop production in Africa. Having soybean varieties with some level of enhanced resistance to rust can make the difference between having an acceptable harvest versus a financially disastrous harvest.

Technical Abstract: The global demand for soybeans has increased by over 145% over the last 30 years and is projected to reach an additional 70-80 million metric tons over the next ten years. Sub-Saharan Africa soybean production is increasing by 6.8% per year compared to a worldwide increase of 4.7%, with small-scale producers accounting for most of the 1.5 million hectares grown in Africa. However, despite this massive expansion in production and demand, African producer yields are less than half of the global average yields. The yield gap is partly attributed to diseases and pests. A significant threat to soybean production is soybean rust, which causes yield losses of up to 90% globally. Proper soybean rust management relies on various factors, including host-resistance. However, information on the rust-resistance level of African varieties is limited. The Pan-African Trial network developed soybean variety trials in diverse African regions to address the yield gap by finding the most adapted varieties. One of the measures in these varieties’ screening trials is documenting differences in soybean disease infection levels when present in the field. This study aimed to classify soybean varieties screened by the Pan-African Trial network due to their rust-resistance level. Seven years of data (2015-2022) totaling 370 trials were considered for the analysis. From those trials, 98 varieties were classified according to their level of rust resistance. A total of 12 varieties were classified as tolerant to ASR across Africa through this framework, which can be utilized to address other disease issues with crop production in Africa.