Studies on intercropping sorghum with finger millet with special emphasis on genotype identification and mixture proportion

During the period 1980-81 two experiments were carried out at Kabanyolo University Farm, with the main objective of identifying suitable genotypes of inter-cropping sorghum with finger millet (Eleusine coracana L.). The subsidiary objectives were to identify the desirable intercropping characters and the extent to which plant population and mixture proportion affect the level of yield advantages. In pure stand the results showed that the medium height (5D x135) sorghum genotype gave higher yield than the others, and Namateera gave the lowest yield per hectare. The yield increased with increase in plant population, and number of grains per head and weight per weight per grain were the more elastic grain components. The mixtures gave similar results. Sorghum yield was higher in pure stands and replacing it with increasing proportions of millet reduced its yield as well as total yield because the millet yield could not compensate the reduction in sorghum yield. The reduction in sorghum yield was attribute to its lower plant population in mixtures. Except for mixtures with Namateera, combined intercrop yield was higher than combined sole crop yield. For all genotypes, combined intercrop yield was also higher than pure stand millet yield. For each combination of sorghum with millet combined intercrop yield was higher where the genotypes differ widely in maturity period. Land Equivalent Ratio (LER) values showed similar results. The mean total LER and hence yield advantages, were highest in mixtures with the short sorghum (SB65) genotype but virtually no overall yield advantage was obtained with the tallest sorghum (Namateera) genotype, although it gave a yield advantage with an early maturing millet genotype, Engenyi. The yield advantages ranged from 0-40%. The LER values further indicated that millet was more competitive than the shorter sorghum genotypes but the taller sorghum genotypes were more competitive than millet; and it is more beneficial to intercrop the species in a 50:50 mixture proportion. The vegetative characteristic measured (leaf area, plant height and tillering) were unsuitable for use as a basis for selecting suitable genotype combinations. Basing on the results of the experiments it is suggested that a grower interested in ‘’maximum yield’’ would get more satisfaction from growing sorghum separately but in situations where growing only one crop is not valid alternative to growing both, i.e. where some yield is needed for at least both crops , then the sorghum and millet should be grown in equal proportions or in a 1 row sorghum : 2 rows millet arrangement. A high plant population of both species is desirable both in pure stand and in mixtures. The yield advantages form intercropping these two species were suggested to be mainly due to complementary use of resources. This could have been achieved through more efficient temporal use of resources due to differences in growth cycles or through more efficient spatial use of light, or soil resources because of the different rooting patterns, future research is needed to assess the relative importance of these factors.