Tropentag, September 10 - 12, 2025, Bonn "Reconciling land system changes with planetary health"

Evaluating grain yield stability of soybean (Glycine max (L.) Merr.) genotypes using GGE biplot analysis across three environments in Zambia

¹University of Ghana, West Africa Centre for Crop Improvement, Ghana
²International Institute of Tropical Agriculture (IITA), Zambia

Abstract

Soybean (Glycine max (L.) Merrill) is a globally important legume crop, valued primarily for its high oil and protein composition, which are key determinants of its economic value. It serves as a major source of vegetable oil and plant-based protein, playing a critical role in global food and feed industries. Soybean is a crucial legume crop contributing to food security and economic livelihoods. However, heterogeneous environmental conditions across agro-ecological zones complicate the identification of genotypes exhibiting both high yield potential and yield stability. Yield variability caused by genotype-by-environment (G×E) interactions remains a major challenge for breeders aiming to develop stable high-yielding genotypes.
Therefore, this study evaluated grain yield stability of seventy soybean genotypes using an alpha lattice design with four replications across three environments in Zambia–Chongwe, Kabwe and Mpongwe. Genotype and genotype-by-environment interaction effects were assessed using GGE biplot analysis to identify superior and stable genotypes. Results indicated significant variation in genotype response to environmental conditions. The highest yielding genotypes were TGx2014-49FZ, SC Signal and TGx2123-73FZ in Chongwe, Kabwe and Mpongwe, respectively. When considering multi-environment performance, TGx2129-18FZ, SC Signal and TGx2014-49FZ emerged as overall high yielding genotypes with SC Signal exhibiting the greatest yield stability, demonstrating adaptability across the experimental sites. The GGE biplot analysis helped identify genotypes adapted to specific environments and stable across environments.

Keywords: Genotype-by-environment interaction, gGE biplot, multi-environment trials, yield stability

Contact Address: Ulitile Muchivete, University of Ghana, West Africa Centre for Crop Improvement, Legon, Ghana, e-mail: umuchivetegmail.com