Genotypes x Environments Interaction of Soybean Lines in Various Shading Environments

Soybean (Glycine max (L) Merr.) planted in land space among stands of other crops especially forest trees experience shading stress due to less sunlight penetration. The objective of the study was to identify the performance and yield stability of soybean genotypes in various shading environments. Field research was conducted in 2018 on 15 soybean genotypes consisted of 12 promising soybean lines and three check varieties (Dena 1, Dena 2, and Grobogan) in 10 shading environments (cassava, maize, orange, teak, eucalyptus, oil palm, and no shading). Randomized block design and repeated four times was used in each location. Result of the study showed that the response of the genotypes to grain yield was significantly difference in each environment or location. Stability of genotypes were grouped into 3, namely 1 genotype classified as unstable and recommended for less optimal environments, 6 genotypes (5 promising lines and 1 check variety) which were classified as stable and adaptive in 10 test locations, and 8 genotypes (6 promising lines and 2 check varieties) classified as unstable in 10 test locations. Based on seed yield and yield components average, one line (Grob/Pander-395-2) had a high average seed yield (1.84 tha-1), high seeds weight per plant (14.8 g), high weight of 100 seeds (21.6 g), and stable in 10 location (indicated by non significant both regression coefficient and regression deviation). Therefore, Grob/Pander-395-2 could be recommended for being grown in shading environments across the country.