Yield Stability in barley-wheat mixed cropping in central highlands of Eritrea

Yield data of a large set of experiments with barley and wheat were analysed in order to assess whether yield stability was greater in mixed cropping than in sole cropping, and to identify which varietal mixture showed most stable grain yields. Stable cropping systems were those having reasonably high mean yield, a regression coefficient (b = 1.0) of the relation between grain yield of the location and the mean yield of each genotype combination/crop ratio or cropping system and a standard deviation (S²di) of the mean yield as small as possible. Mixed cropping with a mean grain yield of 1744 kg ha⁻¹, regression coefficient (b) of 0.995 and a standard deviation (S²dl) of 0.277 was more stable in grain yield than either barley or wheat sole cropping. This stability test confirmed that mixed cropping was more stable than wheat or barley mono cropping and that some varietal mixtures were more stable than others.