Evaluation of introduced cowpea breeding lines in South Africa

Abstract

Cowpea (Vigna unguiculata (L.) Walp) is an important annual leguminous crop in semi-arid and tropics, where it is mainly grown for consumption and livestock feeding. The crop has good morphological and biochemical qualities which make it well adapted to the semi-arid and tropics. However, farmers in South Africa currently lack good seed for planting and experience very low cowpea grain yields. The aim of this study was to evaluate 97 newly introduced cowpea germplasm for adaptation and yield parameters. The study was conducted in two locations in Limpopo Province, with each location having two experiments, experiment I consisted of 57 early maturing cowpea germplasm, and experiment II consisted of 40 medium maturing cowpea germplasm, these materials were introduced from IITA, Nigeria and A&M University, Texas, USA. Both with one local check (Glenda). The first location was at Ukulima Farm near Modimolle in the Waterberg district during 2012/13 and the second was at University of Limpopo experimental farm Syferkuil during 2013/14 summer-planting season. The experiments were laid out as an incomplete randomized block design (lattice design), consisting of 3 replications, four rows per plot with intra row spacing of 25 cm and inter row spacing of 75 cm. Each row was 4m long. The following agronomic variables were collected, in both locations; plant height, number of pods per plant, pod length, number of seed per pod, number of branches, hundred seed weight and grain and fodder yield. Data was subjected to ANOVA using statistical software, Statistic 9.2. The variances of the parameters measured were summarized in ANOVA table. The treatments that showed significant difference were separated using Duncan Multiple Range at 5% level of significance. The result showed significant difference (P<0.05) among cowpea varieties for the following yield parameters; plant height, number pods per plant, number of branches, seed weight, pod weight and hundred seed weight. In experiment I the mean plant height, number of branches, mean pod length, total pod weight, weight of seeds per pod, hundred seed weight and number of seed per pod were respectively (100 cm, 21, 23 cm, 1413.4 kg/ha, 1121.62 kg/ha, 28.283g and 16) and were greater than the control Glenda (49 cm, 15, 14 cm, 777.82 kg/ha, 622.87 kg/ha, 13.300 g and 13). In vi experiment II the mean plant height, number of branches, mean pod length, total pod weight, weight of seeds per pod, hundred seed weight and number of seed per pod were respectively (97 cm, 21, 21 cm, 1546.19 kg/ha, 1245.11 kg/ha, 27.363 g and 16) and these were better than the control, Glenda (50 cm, 15, 17 cm, 795.11kg/ha, 661.01 kg/ha, 18.393 g and 13). Weight per 100 seeds showed that 51 and 32 breeding lines had weights higher than Glenda in the early and medium maturity trials, respectively. The evaluated cowpea varieties varied in performance between the two locations. The above results indicate the superiority of the introduced breeding over the local check as well as the potentials of using these promising lines for the development of better adapted germplasm in South Africa. The lines with better agronomic characters and yield performance in the two locations are recommended for seed production to meet the immediate needs of farmers, after due registration with DAFF at Pretoria. Data generated from the studies will contribute useful information to the data-base of the characteristics of these cowpea lines. Key words: Evaluation, Cowpea germplasm, Adaptation, Vigna unguiculata.