Evaluation of adaptability of early-maturing (FAO 140-170) grain corn hybrids in multi-environment trial

The article shows the results of the evaluation of adaptability of early-maturing (FAO 140-170) grain corn hybrids under different environmental conditions. We conducted the research in 2021 in 8 areas of multi-environment trials which belonged to 5 regions of Russia. The adaptability of the corn hybrids was evaluated according to the regression coefficient (bi), the deviation from regression of variety at the environment (Si2), stress tolerance (Ymin-Ymax), genetic flexibility ((Ymin-Ymax)/2) and coefficient of adaptability (Ка). Volgograd (irrigation) (Ij=+2.14), Nalchik (Ij=+0.52), Pyatigorsk (Ij=+0.42), Omsk (Ij=+0.23) and Voronezh (Ij= +0.19) had favourable environments. Unfavourable conditions were in Belgorod (Ij=-0.23), Volgograd (rainfed agriculture) (Ij=-0.98) and Chelyabinsk (Ij=-2.29). We found the significant influence of environmental conditions (61.39%), genotype (15.44%) and genotype x environment interaction (18.24%) on corn grain yield. The most yielding hybrids in some areas were Vo 170-27 (9.47 t/ha, Volgograd - irrigation), Vo 170-25 (8.21 t/ha, Nalchik), Vo 170-24 (7.53 t/ha, Pyatigorsk) and Vo 140-24 (7.36 t/ha, Voronezh). We found productive corn hybrids (Vо 170-24, Vо 170-25 and Vо 170-27) with regression coefficient values bigger than one (bi=1,26-1,41) and the highest coefficients of adaptability in favourable environments (Ка=1,10-1,14) for intensive production. Vо 140-26, Vо 140-27 and Vо 170-28 hybrids had ecological plasticity (bi=0,98-1,09) and high grain yield, which varied according to different environmental conditions, genetic flexibility and adaptability. We recommended these hybrids for a wide range of environments. Hybrids Vо 140-28 and Vо 170-26, which were stress-tolerant and had low regression coefficients (bi=0,86-0,88), are better to choose for unfavourable conditions or extensive production systems.