Genetic variability for developmental and yield attributes of sorghum and pigeonpea under Inter and intra-species competitions B SNairauthorIn order to study the effect of interspecies competition and test the plant type concept, two experiments were conducted over two years during Kharif 1983 and 1984 under auspices of the All India Co-ordinated Sorghum Improvement Project. In experiment I, twenty genotypes of sorghum differing in canopy structure and genetic background including released and prerelease varieties, hybrids and some of the parental lines were grown in intercropping with a pigeonpea variety, HY 8 as well as solecropping. The intercropping represents inter-species competition while sole cropping represents intra-species competition. The competition effects due to sorghum, due to pigeonpea and due to sorghum x pigeonpea interaction were studied in second experiment by growing four sorghum hybrids and four different pigeonpea varieties in all possible combinations. Experiments were laid out in RBD with three replications. Developmental characters were recorded at three stages of growth and yield characters at maturity Sorghum1985Andhra Pradesh Agricultural University;Department of Genetics and Plant BreedingThesis