ISSN: 0041-3216 (Online), 0041-3216 (Print)
Volume 85 Number 1
Performance of Released Faba Bean (Vicia faba L.) and Field Pea (Pisum sativum L.) Varieties for Important Traits under Sole and Mixed Cultures I. Grain yield. (46)
A field experiment was conducted in 2000 and 2001 at two locations (Holetta and Denbi) in Ethiopia to evaluate the performance of released faba bean and field pea varieties under sole and mixed cultures. Thirty-seven faba bean and field pea varietal mixtures, including a local one, and 6 pure components each of faba bean and field pea were evaluated in a 7 x 7 triple lattice design with 3 replications. Data on grain yield and land (LER) and income (IER) equivalent ratios were recorded and analyzed. Differences among the treatments (T) and cropping systems were significant for grain yield and, overall, a number of mixtures out yielded the corresponding sole cultures and the local mixture. LER and IER values of more than unity were also recorded for a number of mixtures. Location (L), and L x T effects for LER and IER and year (Y), location, T x L, T x Y and T x Y x L effects for grain yield were also significantly different. However, location effects represented the largest proportion of the total variation (92%), indicating the relative importance of spatial over temporal replication of experiments. Mixed-cropping was found to be more advantageous in terms of grain yield and resource use efficiency than to the corresponding sole cultures, as a number of varietal mixtures outperformed their respective sole cultures and the local mixture. Genotypes developed for a sole culture may perform well under a mixed system as well. Genotypes developed for higher yield under a mixed culture may also have better resource use efficiency. Therefore, selection of better performing genotypes under one system might also identify good genotypes for the other but a more systematic study maybe needed for further confirmation. Field pea was found to be more competitive and aggressive in a mixed culture than faba bean. Therefore, breeding efforts should focus in a compromised manner on decreasing the level of aggressiveity in field pea and increasing the competitive ability in faba bean, in addition to improved productivity in both crops. Suitable ideotypes for mixed-cropping and the morpho-physiological basis of suitability should be determined for maximized exploitation in future varietal development endeavors.
Keywords: Aggressivity (A), crowding coefficient (k), faba bean, field pea, income equivalent ratio (IER), land equivalent ratio (LER), mixed-cropping