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Determination of Suitable Variety and Plants per Stand of Cowpea (Vigna Unguiculata L.Walp) in the Sandy Soil, Sudan
Advances in Life Sciences , 2012, DOI: 10.5923/j.als.20120201.01
Abstract: The study was conducted to determine the effects of four different numbers of plants per stand on the performance of three cowpea varieties under rain-fed conditions. A field experiment was conducted for two successive rainy seasons (2007/08-2008/09) in sandy soil of North Kordofan State, Sudan. The three varieties of cowpea (BLedi, an old local cultivar and two recently improved cultivars, Haydoob and Eien Elgazal) were sown in four patterns (one, two, three and four plants per stand). The experiment was laid out in a randomized complete block design (RCBD) in four replications. The results showed that, plants/stand had a significant effect on most of the attributes measured. Increased plants/stand significantly increased grain yield per unit area and reduced the number of pods per plant, 100-grain weight, grain yield per plant and harvest index. The local cultivar was late in maturity and had heavier 100-grain weight, greater grain yield per plant, greater final grain yield (t/ha). The Ein Elgazal was earlier in maturity and scored the highest values of harvest index.
Effects of Cropping System and Cowpea Variety on Symbiotic Potential and Yields of Cowpea (Vigna unguiculata L. Walp) and Pearl Millet (Pennisetum glaucum L.) in the Sudano-Sahelian Zone of Mali  [PDF]
Zoumana Kouyaté,Tatiana Krasova-Wade,Inamoud Ibny Yattara,Marc Neyra
International Journal of Agronomy , 2012, DOI: 10.1155/2012/761391
Abstract: Many cowpea varieties (Vigna unguiculata L. Walp) have been proposed by research in Mali. None of these varieties were investigated for their symbiotic potential in terms of root nodulation and mycorrhizal infection. An experiment was conducted at Cinzana Research Station, from 2007 to 2009 with an objective to identify a cowpea variety with high symbiotic potential which may improve millet/cowpea cropping global production. Randomized complete block (RCBD) design with a factorial combination of 3 cowpea varieties (IT89KD-374, CZ1-94-23-1, and CZ11-94-5C) and 2 cropping systems (millet/cowpea intercropping and cowpea-millet rotation) was used. On farm test was conducted to evaluate CZ11-94-5C and IT89KD-374 nodulation performance. Cowpea variety CZ11-94-5-C had the highest nodule number and nodule weight. Millet/cowpea alternate rows intercropping (1/1), only, had a significant influence on cowpea root infection rates by mycorrhizae, on the 45th day after emergence. IT89KD-374 gave the best cowpea grain yield (1540?kg?ha?1) in sole crop. The highest millet grain yield (1650?kg?ha?1) was obtained under CZ11-94-5C-millet rotation. Farmers' fields assessments results confirmed CZ11-94-5C performance on research station. The CZ11-94-5C cowpea variety needs to be more characterized. 1. Introduction Cowpea (Vigna unguiculata L. Walp) is the main legume food crop in the Sudano-Sahelian zone of Mali [1]. It is one of the main pulses contributing to the economy of nitrogen in cropping systems with low input through the biological nitrogen fixation [2]. This symbiotic nitrogen fixation can reduce the rate of depletion of cultivated soils where legume-cereal rotation is practiced [3]. If cowpea is nodulated by powerful strains of Bradyrhizobia, 90% of the required nitrogen for maximum yield can derive from biological nitrogen fixation[4]. According to Peoples et al. [5] Dakora and Keya [6], the values of N contribution by various legumes, including Cowpea (Vigna unguiculata L. Walp), are important (50 to 300?kg N?ha?1?yr?1). These values depend on the legume plants density, the cropping system, and the legume genotype [7].Venkateswarlu et al. [8] showed that cowpea Bradyrhizobia nodulating population density depends very significantly on the cultural practices rather than rainfall. So far, very little attention has been addressed to the agromicrobiological aspects in cowpea research in Mali. In order to fill this gap, the present study was conducted from 2007 to 2009 at Cinzana Agronomic Research Station in the Sudano-Sahelian zone of Mali. The objective was to
Effectiveness and efficiency of chemical mutagens in cowpea (Vigna unguiculata (L.) Walp)
D Dhanavel, P Pavadai, L Mullainathan, D Mohana, G Raju, M Girija, C Thilagavathi
African Journal of Biotechnology , 2008,
Abstract: A study was undertaken in a cowpea (Vigna unguiculata (L.) Walp.) variety CO 6 to assess the efficiency and effectiveness of chemical mutagens; ethyl methane sulphonate (EMS), diethyl sulphate (DES) and sodium azide (SA). EMS treatments were found highly effective than the other chemicals. Mutagenic effectiveness and efficiency decreased with increase in all mutagenic treatments.
Floral Biology and Pollination Ecology of Cowpea (Vigna Unguiculata L. Walp)  [cached]
Ige, O. E.,Olotuah, O.F,Akerele, V.
Modern Applied Science , 2011, DOI: 10.5539/mas.v5n4p74
Abstract: Studies on the floral biology and pollination ecology of three varieties of cowpea (Vigna unguiculata L. Walp) were carried out. The varieties studied were Var. Oloyin, Var. Sokoto, and Var. Drum. Cowpea is a self pollinated crop which is encouraged by the arrangements of the floral parts. However, Insects visiting cowpea flowers have been implicated in the movement of pollen from one cowpea plant to another. Flower opening of cowpea begins between 6:00am and 6:30am and closes between 11:30am and 12:00pm. Pollen analysis showed similarities in the pollen morphology of the cowpea varieties. Moreover Var. Drum produced the highest number of pollen grains per flower in terms of pollen productivity.
Response of Cowpea (Vigna unguiculata L. Walp.) to Water Stress and Phosphorus Fertilization
V.G. Uarrota
Journal of Agronomy , 2010,
Abstract: This study was conducted in the experimental college of agriculture and forestry, in Maputo-Mozambique, in order to evaluate the response of cowpea (Vigna unguiculata L. Walp.) to irrigation and phosphorus and test the hypothesis that high levels of phosphorus improves the tolerance of plants to water stress. We used a variety IT 18 of cowpea, short cycle and ended. The experiment was subdivided into building plots complete block design with five repetitions, the irrigation factor was fixed at the main plot with two levels (with irrigation and without irrigation) and phosphorus factor in sub-plots with 3 levels (0, 20 and 40 kg ha-1 of phosphorus). The fertilization strongly influenced the yield and the number of pods per plant in both irrigation conditions. The effect of fertilizing phosphorus was higher under irrigation. The interaction was significant only for grain yield and number of pods, which means that the effect of phosphorus in these two variables has not been the same for the two levels of irrigation, high levels of phosphate fertilizer (P2O5) have improved the tolerance of cowpea when not irrigated.
Symbiotic functioning and bradyrhizobial biodiversity of cowpea (Vigna unguiculata L. Walp.) in Africa
Flora Pule-Meulenberg, Alphonsus K Belane, Tatiana Krasova-Wade, Felix D Dakora
BMC Microbiology , 2010, DOI: 10.1186/1471-2180-10-89
Abstract: Field measurements of N2 fixation revealed significant differences in plant growth, δ15N values, %Ndfa and amounts of N-fixed between and among the 9 cowpea genotypes in Ghana and South Africa. Following DNA analysis of 270 nodules from the 9 genotypes, 18 strain IGS types were found. Relating nodule function to the 18 IGS types revealed significant differences in IGS type N2-fixing efficiencies. Sequencing the 16S - 23S rDNA gene also revealed 4 clusters, with cluster 2 forming a distinct group that may be a new Bradyrhizobium species. Taken together, our data indicated greater biodiversity of cowpea bradyrhizobia in South Africa relative to Botswana and Ghana.We have shown that cowpea is strongly dependant on N2 fixation for its N nutrition in both South Africa and Ghana. Strain IGS type symbiotic efficiency was assessed for the first time in this study, and a positive correlation was discernible where there was sole nodule occupancy. The differences in IGS type diversity and symbiotic efficiency probably accounts for the genotype × environment interaction that makes it difficult to select superior genotypes for use across Africa. The root-nodule bacteria nodulating cowpea in this study all belonged to the genus Bradyrhizobium. Some strains from Southern Africa were phylogenetically very distinct, suggesting a new Bradyrhizobium species.Cowpea (Vigna unguiculata L. Walp.) is a major food crop in Africa, where its leaves, green pods and grain are eaten as a dietary source of protein. The cowpea grain contains about 23% protein and 57% carbohydrate, while the leaves contain between 27 - 34% protein [1]. The leaves and grain are also supplied as high protein feed and fodder to livestock. Cowpea is the most commonly grown food legume by traditional farmers in Sub-Saharan Africa, possibly because of its relatively wide adaptation to drought and low-nutrient environments. Cowpea freely forms root nodules with some members of the Rhizobiaceae such as Rhizobium and Bradyr
Physiological and biochemical responses of cowpea (Vigna unguiculata (L.) Walp) to ozone
Chanin Umponstira,Warin Pimpa,Suckaluck Nanegrungsun
Songklanakarin Journal of Science and Technology , 2006,
Abstract: The aim of this research was to investigate physiological and biochemical responses of cowpea (Vigna unguiculata (L.) Walp) to ozone. There were two main factors of the experiment; level of ozone concentration at 40 and 70 ppb and plant ages at 7 and 21 days. Plants were grown in fumigation chambers in which inlet air was filtered by a charcoal filter. Additional ozone was given 8 hours/day for 7 days in ozone fumigating chambers. The ozone concentration in the control chambers was less than 10 ppb. The results showed the biomass of ozone-fumigated plants was significantly lower and leaf injury of ozone fumigated plants was significantly greater compared to the control group. The major visible-injury symptom appeared as chlorosis on the upper surface of the leaves. Antioxidant levels in the charcoal filtered (CF) plants and ozoned plants had significant differences because of their detoxification role in removing ozone and its derivatives. The ozone treatment of 7-day-old plants showed superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) levels significantly higher than in 21-day-old plants and total ascorbate concentrations significantly lower than 21-day-old plants. These results showed that different ozone concentrations exhibit different effects on antioxidant production. Analysis of antioxidants daily for 7 days found that antioxidant levels rapidly changed. Notably, SOD and total ascorbate could be selected as indicators for ozone-effect monitoring in plants. This indicates that cowpea is sensitive to ozone and may be usable as an ozone bioindicator. In conclusion, plant age, ozone concentration and the duration to exposure to ozone were the main physiological or biochemical responses of cowpea. An efficient defense system was generated from a combination of antioxidants.
Comparison of Some Cowpea (Vigna unguiculata L. Walp)  [PDF]
Erkut Peksen,Cengiz Artik
Journal of Agronomy , 2004,
Abstract: In this study, six cowpea genotypes from different locations in Turkey (Dalbah e, Doganca, Duragan, Igdir, Kirazlik 1 and Kirazlik 2) and two registered cultivars (Akkiz-86 and Karag z-86) as control were compared for their seed yield and yield related characters during 2002 and 2003 years. In addition, correlation and path coefficients between seed yield per plant and yield related characters were determined. The highest seed yields per hectare were obtained from Kirazlik 2 (1120.9 kg ha-1), Doganca (1093.1 kg ha-1), Duragan (1078.6 kg ha-1), Kirazlik 1 (1066.6 kg ha-1), Dalbah e (993.6 kg ha-1) and Igdir (922.1 kg ha-1). Seed yields of Akkiz-86 and Karag z-86 were highly significantly lower than the other genotypes. Karag z-86 was the superior for seed yield per plant (10.70 g plant-1). This followed by Doganca (8.27 g plant-1) and the rest of the genotypes were not statistically different from each other for seed yield per plant. Pod length and 100 seed weight showed a positive and highly significant correlation with seed yield per plant. Path analysis results revealed that pod length had the highest direct positive effect on seed yield per plant, followed by 100 seed weight and pods number per plant. On the other hand, seed yield per plant was directly and negatively affected by first pod height and branches number per plant.
Antioxidant Activity of the Extracts of Some Cowpea (Vigna unguiculata (L) Walp.) Cultivars Commonly Consumed in Pakistan  [PDF]
Muhammad Zia-Ul-Haq,Shakeel Ahmad,Ryszard Amarowicz,Vincenzo De Feo
Molecules , 2013, DOI: 10.3390/molecules18022005
Abstract: The present investigation has been carried out to determine the antioxidant activity of the methanolic extracts obtained from four cultivars of cowpea ( Vigna unguiculata (L) Walp.) seeds. Phenolic compounds present in the extracts showed the antioxidant and antiradical properties when investigated using a linoleic acid peroxidation model, FRAP, ORAC and TRAP assays, as well as DPPH, hydroxyl, nitric oxide and superoxide radical scavenging activity. The HPLC analysis of the cowpea extracts showed the presence of neochlorogenic acid, chlorogenic acid and caffeic acids. The results indicated that methanolic extract of the cowpea resembled in the aforementioned activities those from other leguminous seeds and pulses. Phenolic constituents contained in cowpea may have a future role as ingredients in the development of functional foods.
Genetic diversity in cowpea [Vigna unguiculata (L.) Walp.] varieties determined by ARA and RAPD techniques
La ty Fall, Diaga Diouf, Mame Arama Fall, Fran ois Abaye Badiane, Mamadou Gueye
African Journal of Biotechnology , 2003,
Abstract: Cowpea, Vigna unguiculata (L.) Walp. presents phenotypical variabilities and in order to study the genetic diversity of cultivated Senegalese varieties, two experimental approaches were used. First, a physiological characterization based on nitrogen fixation was used to assess cowpea breeding lines. Inoculation with two Bradyrhizobium strains (NGR234 and ISRA312), showed a difference in nitrogen fixation potential between the cowpea varieties. Diongoma is the highest nitrogen fixing variety, whereas Mouride is the lowest. The second approach employed genetic characterization based on DNA polymorphism to screen. Results suggest that random amplified polymorphic DNA (RAPD) technology can be used to reorganize the national germplasm in order to eliminate the putative duplicates, and to identify elite varieties. (African Journal of Biotechnology: 2003 2(2): 48-50)
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