International Journal of Pure and Applied Sciences and Technology

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1 Int. J. Pure Appl. Sci. Technol., 2(2) (202), pp. -7 International Journal of Pure and Applied Sciences and Technology ISSN Available online at Research Paper Evaluation of Eight Cowpea (Vigna unguiculata l. Walp) Species for Yield and Associated Traits I.A. Ekpo, 2, R.B Agbor, *, A.N. Osuagwu, E.C. Okpako and B.E. Ekanem, 3 Department of Genetics and Biotechnology, University of Calabar, Calabar, Cross River State, Nigerias 2 Department of Biological Sciences, Federal University Lafia, Lafia, Nasarawa State, Nigeria 3 Department of Science Technology, Akwa Ibom State, Polytechnic Ikot-Osurua, Nigeria * Corresponding author, (agborreagan@yahoo.com) (Received: ; Accepted: 4-9-2) Abstract: Eight cowpea (Vigna unguiculata) species were evaluated for yield and associated traits. The associated parameters studied were leaf area, plant height, number of branches and leaf number and the result obtained showed significant differences (p>0.05). Significant differences (p<0.05) were also observed in days to germination and days to 50% flowering, while 00% seed weight shows no significant difference (p>0.05). From the result obtain it can be concluded that IT86D-79 and IT90-K76 collections had the best results in most of the parameters evaluated. Keywords: Cowpea, Yield, Associated trait and Evaluation Introduction Cowpea (Vigna uniguiculata) commonly known as beans is an important, versatile food crop. It is the most ancient human food. It belongs to family of fabaceae (Leguminoisae) and subfamily of papillnoideae. Cowpea has been intercropped for long time with various other crops such as maize, wheat, millet, sorghum (Johnson, 970). It can be utilized in various ways ranging from the use of young green seedling as vegetables and also forage for livestock to its consumption as beans (Kay, 979). It is an excellent source of protein which is enriched by amino acids, lysine and tryptophan. It is very nutritious with free metabolites or other toxins (Kay, 979). Cowpea is widely grown in sub- Saharan Africa; it is widely planted under rain fed conditions in domestication which is associated with pear in South Africa. It is distributed in the tropics and sub-tropics (Allen, 983). Economically, cowpea is utilized by man in different ways. The seed contains approximately 49% protein and 20-

2 Int. J. Pure Appl. Sci. Technol., 2(2) (202), % fat and oil (Donald, 970). Generally, cowpea grows in areas of low rainfall as high rainfall lead to crop failure. Many of the cowpea phenotype exhibit heat induced suppression of floral bud development, which result in two weeks delay in flowering when plant are found in very hot field environment under long days (Ehlers and Hall 997). A mean temperature of 27 o C is optimum for god pod formation and seed yield though it performs better in region with rainfall of mm per annum. Loamy soil is considered the best for the cultivation of cowpea with ph value of 6-7 for optimum growth. Cowpea can survive and thrive in a broad range of conditions its few pests consist of aphids and stank bugs and its one cultural problem is that it does not like wet feet. Varieties with shorter maturity dates are available for gardeners with a less lengthy summary. The success of most crop improvement programme largely depends upon the genetic variability and the heritability of desirable traits in reproductive period and grain yield of cowpea under high temperature condition and the duration of reproductive period (Singh, 997). The high heritability may explain why traditional breeding for cowpea growth is so effective since the design of experiment and method of data analysis is novel, this report can serve as educational note for students in the area of quantitative genetics and plant breeding (Fawole, 999). Most cowpea breeders employ back cross or bulk breeding method to handle segregating population because cowpea is self pollinating specie and varieties are pure lines. (Higher grain yields and improve grain quality are the primary breeding objectives of nearly all programs. In addition, breeches seek to incorporate a wide range of abilities and biotic stress resistance/tolerance characters. The general strategies of most breeding program is to develop a range of high yielding cowpea varieties adapted to different agro-ecological zones that posses regionally preferred traits for plant type, growth habit, days to maturity and seed type. Cowpea leaves and stem are also important source of high quality hay for livestock feed (Tarawali et al, 997). It is also available component of faming system in areas where soil fertility is limiting. This is because cowpea has a high rate of nitrogen fixation (Flawed and Hall, 987) cowpea is also well recognized as a key component in crop rotation schemes because of its ability to help restore soil fertility for succeeding cereal crops (Carsky et al, 2002). Certain characteristics of traits and hereditary exist in agricultural crops which are of breeders interest. Varietals differences of cowpea in terms of growth pattern, seed maturity date are extremely diverse from plant to plant, making breeding programs for cowpea more complex than other crops (Baker, 989). Therefore, there is great need for genetic improvement and development of cowpea varieties with acceptable and better traits which can be achieved through the study of the different growth and yield component that occur in different varieties of cowpea as low seed yields can be attributed to unfavorable agronomic practices by farmers. Therefore varietal and phenotypic differences occurring since different varieties of cowpea as low seed yields which can be attributed to unfavourable agronomic practices by farmers. Therefore varietal and phenotypic differences occurring in different varieties of cowpea shall form the basis of this study. Materials and Methods Soil Preparation and Planting Twenty four polythene bags were gotten from (IITA) Ibadan. The 24 bags were filled with loamy soil each weighing 0kg. The eight cowpea species (IT93K-452-, IT89KD-39, IAR48, IT90K-76, IT85D-79, IT8985, IT90K-277-2, IT89KD-288) were gotten from (IITA) Ibadan for planting. Seeds were planted four per bags, 3 days after soaking in water. Cultural Practices Weeding was done two weeks after germination of seed and subsequent weeding was done at 3 weeks intervals. Two weeks after planting, the plants were watered for the leaves to be fresh. Cypermethrin Ec insecticide was used four weeks after planting to control pest. This was applied at the rate of 20ml/25 liters of water using a hand sprayer and application was repeated weekly.

3 Int. J. Pure Appl. Sci. Technol., 2(2) (202), Staking Cowpea being a climber plant needs sticks on which it can twine so as to prevent it from creeping on the bare soil surface hence sticks were provided for it during the course of the experiment. Watering was done every two weeks interval in order for plants to remain fresh and also increase in soil fertility. Data Collection Data were collected on the following parameters: plant height, number of plants, number of branches, length/width of the terminal leaflet, number of pods per plant, number of seeds per pods, 00 seed weight and pod length. Statistical Analysis Data collected were subjected to analysis of variance test and the means separated using the least significant difference (LSD) test in cases of significance. Results and Discussion The mean values of the yield and associated traits component of the species of cowpea are presented in Table and 2. The result shows that there were significant differences (P<0.05) in the days to seed emergence, IT93K-452- germinated earlier at 3.67 days than other species. The duration of an experiment also affects the differential changes that might occur in the morphological features of a plant over a given time. The number of leaves of the species were significantly different (P<0.05), At two weeks, IT86D-79 had the highest number of leaves with a mean of 7.25, at 4 weeks IT and IT8D-985 had the highest number of leaves with a mean of 8.55 and 8.42 respectively. At six weeks, IT90-K76 and IT89KD-39 had the highest number of leaves, with a mean value of and respectively. The result on plant height also shows that there were significant difference (P<0.05) among the species with IT90K having the highest height at 6 th week than the other plant species (Table ). The result on the leaf area of the species shows that the leaf area differs significantly (p< 0.05) among the species (Table 2). The first species to flower was IT86D-79 with mean of 44.67, while IT90k-76 flowered last with a mean of Significant differences (P< 0.05) were also observed in the days to 50% flowering; IT89KD-39 flowered before other species. The result obtained for the pod length shows that IT86D-79 had the longest pod while IT8D-985 had the shortest pod length. The pod weight was also significantly different (P< 0.05), IT86D-79 had the highest weight while IT89KD-39 had the lowest weight. The seed weight of the species were not significantly different (P>0.05) (Table 2). Table : Morphplogical Studies of 8 Varieties of Cowpea Planted in Calabar for Six Weeks Varieties Plant height at 2 nd week Plant height at 3 rd week Plant height at 4 th week Plant height at 5 th week Plant height at 6 th week IT a ± a ± a ± d ± e ±.98 IT89KD a ± a ± a ± d ± d ± 4.95 IT93K b ± a ± a ± d ± c ± 7.29

4 Int. J. Pure Appl. Sci. Technol., 2(2) (202), IT90-K a ± a ± a ± c ± c ± 6.58 IT90K a ± a ± a ± b ± a ±.46 IT8D a ± a ± a ± a ± b ± 3.72 IT89KD a ± 7.54 a ± a ± d ± e ± IAR a ± a ± a ± c ± e ± 2.99 Data were expressed in mean and standard error (X ±S.E) in triplicate. Means with the same superscript on the vertical array represent no significant difference. PARAMETE RS Days to germination No. of leaves at 2 weeks No. of leaves at 4 weeks No. of leaves at 6 weeks Leaf area at 2 weeks Leaf area at 6 weeks No. of days to flower initiation No. of days to flowering Table 2: Growth performance of eight cowpea species IT IT89KD-39 IT90-K76 IT8D-985 IT93K AR a ± a ± a ± c ± c ± b ± a ± b ± a ± d ± e ± e ± a ± a ± a ± a ± b ± b ± a ± b ± c ± a ± e ± a ± c ± b ± a ± d ± e ± e ± b ± e ± d ± f ± c ± d ± c ± a ± c ± c ± b ± c ± a ± e ± e ± c ± b ± c ±3.34 Pod length 4.58 a ± a ± c ± d ± b ± a ±2. Pod weight a ± c ± f ± e ± d ± b ± % seed 00 a ± a ± a ± a ± a ± a ±2.26 weight Data were expressed in mean and standard error (X ±S.E) in triplicate. Means with the same superscript on the horizontal array shows no significant difference.

5 Int. J. Pure Appl. Sci. Technol., 2(2) (202), Figure : Days to emergence Figure 2: Number of leaves of cowpea varieties

6 Int. J. Pure Appl. Sci. Technol., 2(2) (202), Figure 3: Leaf area of cowpea In this study growth and yield components of cowpea varieties were evaluated. The growth habit of different varieties studied varied. The observation is in line with the work of (Patel et al, 990) who observed that there is variability in the growth habit within the species. Pod length is an important trait in cowpea, plant breeders are interested in developing new species with concentrated seed set for the benefit of growers using expensive hand labor or machine harvest systems. The result of this study showed significant differences in days (p<0.05) to germination, days to 50% flowering, number of leaves, plant height, number of branches, leaf area number of days to flower initiation, pod length and pod weight while no significant differences (p> 0.05) were observed in 00% seed weight of the species. High leaf area was observed in IT89KD-39 as compared to others large leaf area has been associated with high solid contents in African yam bean pod (Takang, 2002) but not with high number of seed, therefore there is a need for further investigation on the relationships among leaf area, photosynthetic rate, and the time leaves remain photosynthetically active. Such information could help explain the role of source strength in determining seed set and development in cowpea. Highest number of leaves was observed in IT at six weeks and this was in line with work by Takang (2002) on African yam bean, he reported that associated traits directly determine the amount of photosynthesis that would be available for plant growth and seed yield. Therefore, the more the number of leaves posses by a plant, the more potential growing point for seed set which may consequently result in large number of trait per plant. Walters and Wehner (994) also evaluated African yam bean germplasm from West Africa for early flowering as well as the correlation between early flowering and total yield. The result from this work showed that IT was the first to flower and the last to reach 50% flowering. The differences in number of days to flower initiation and number of days to 50% flowering were significantly different (p< 0.05), this indicate that IT86D-79 is an early species but late maturing thus, it can be utilized in cowpea breeding programme. Cramer and Wehner (998) however, showed that the number of branches per plant exhibited positive correlation with total yield in cowpea and the result of this study is in line with their work since the number of branches at 4 weeks and 6 weeks correlated positively with pod weight. Cramer and Wehner (998) also reported that plant height contributed to yield as it leads to resulting increase in

7 Int. J. Pure Appl. Sci. Technol., 2(2) (202), the number of female flowers and in number of pods. This fact was supported by (Takang, 2002), the result of these study also shows that the plant height can also contribute positively to the pod weight of the plant. Conclusion It can thus, be concluded that IT86D-79 and IT90-K76 collections had the best results in most of the parameters evaluated. However, base on their growth performance they should be widely cultivated in order to ensure their availability in market. References [] B.B. Singh, Performance of promising cow pea varieties at mingibir, Annual Report, Project II Cowpea Cereals System Improvement in the Savanna, (997), 4-5. [2] C.S. Cramer and T.C. Wehner, Fruit yield and yield component means and coloration of four legumes, Journal of American Society of Horticultural Science, 23(998), [3] D.J. Allen, The Pathology of Tropical Food Legumes, John Wiley and Sons, Chichester, 983. [4] F. Walter and R. Wehner, Chemical attributes of cowpea lines resistant and susceptible to Callosobruchus maculates, Stored Prod, 26(994), 2-5. [5] J.D. Ehlers and A.E. Hall, Cowpea (Vigna unguiculata (L) walp), Field Crops Res., 53(997), [6] J. Takang, Soy bean in human diet, FAO of the United Nations, Italy, 3 (2002). [7] K. Johnson, Department of Botany and Plant Sciences, Institute of Agriculture Research Samara, Ahmadu Bello University, Zaria, 970. [8] R.J. Carsky, B. Vanlauwe, O. Lyasse, Cowpea rotation as a resource management technology for cereal-based sys-tems in the savannas of West Africa, In: C.A. Fatokun, S.A. Tarawali, B.B. Singh, P.M. Kormawa and M. Tamo (eds), Challenges and Opportunities for Enhancing Sustainable Cowpea Production, International Institute of Tropical Agriculture, Ibadan, Nigeria, [9] S.A. Tarawali, B.B. Singh, M. Peters and S.F. Blade, Cowpea haulms as fodder, In: B.B. Singh, D.R. Mohan Raj, K.E. Dashiell and L.E.N. Jackai (eds), Advances in Cowpea Research, Co-Publication of International Institute of Tropical Agricul-ture (IITA) and Japan International Research Center for Agricultural Sciences (JIRCAS), Sayce, Devon, UK, 997. [0] T. Donald, The cowpea in the African areas of Rhodosia, Agricultural Journal, 678(970), [] T. Fawole, Genetics and increase cowpea production in Nigeria: Genetics and food society in Nigeria, 26 (999), [2] T.A. Baker, S.S. Shade and B.B. Singh, Physical and chemical attributes of cowpea lines resistant and susceptible to Callosobruchus maculates (F), Stored Prod. Res, 25(989), -8. [3] W. Kay, Guidelines for the production of cowpea (Vigna unguiculata), Field Crop Abstracts, 27(979),