Effectiveness of different breeding methods in crop improvement is important to the breeders of a particular crop. .Hence, the effectiveness of three breeding methods namely, pedigree, single seed descent and modified bulk were evaluated using two cowpea [Vigna unguiculata (L) Walp] crosses CP 19 x Waruni and CP 20 x CP 22, at the Grain Legumes and Oil Crops Research and Development Center at Angunakolapellessa in Sri Lanka. All three breeding methods were imposed from the F2 populations of two cowpea crosses during 2011 Yala season and F3, F4 and F5 populations for each method were established during 2012/12 Maha, 2012 Yala and 2012/13 Maha seasons, respectively. The ten best lines from each method were selected at F5 generation and advanced to F6 generation. The selected 30 lines from the three breeding methods, two parents and three standard checks were tested for each cross in a Randomized Complete Block Design during 2013 Yala season. Data were recorded on plant height at maturity, number of peduncles per plant, number of pods per plant, number of seeds per pod, average length of pod, hundred seed weight and yield per plant in F4, F5 and F6 generations. Lines/methods were found to be significant (p<0.05) for all the characteristics studied at F6 generation, except the number of pods per plant and pod length in CP 19 x Waruni and seed per pod in CP 20 x Cp 22. The mean sum of squares of days to maturity in CP 19 x Waruni and seed per pod in both crosses were found to be significantly different among three breeding methods but for other characteristics, methods were found to be not significantly different (p<0.05). The pods per plant and hundred seed weight recorded attractive narrow sense heritability values and significant intergeneration correlations. Positive phenotypic correlations were recorded between the seed yield and pods per plant in F4, F5 and F6 generations. Accordingly, in cowpea improvement, comparable results could be obtained among pedigree, single seed descent and modified bulk methods. In addition, indirect selection for higher number of pods per plant and hundred seed weight could increase seed yield.
Tropical Agricultural Research Vol. 26 (2): 294 – 302 (2015)