Improving cultivation of cowpea in West Africa

Cowpea [Vigna unguiculata (L.) Walp.] is a legume crop of vital importance to the livelihoods of millions of people in West and Central Africa (WCA). It provides a nutritious grain and a less expensive source of protein for both rural and urban poor consumers (Inaizumi et al., 1999). It can be grown and harvested in as little as 60–80 days. This enables households to harvest leaves and grains for consumption or sale during the ‘hungry season’ when grain reserves from the previous cereal harvests have been depleted and current crops are not ready for harvest. Most of the world’s cowpea (>90) is grown in sub-Saharan Africa, most of which is in West Africa particularly in Nigeria and Burkina Faso. Over 12.61 million ha are grown to cowpea worldwide, with an annual grain production of about 5.59 million tons (FAO, 2014). Of this amount, Africa accounts for 94% of grain production. Nigeria is the largest cowpea producer in the world and accounts for over 2.5 million tons grain production from an estimated 4.9 million ha (FAO, 2014). Other major producers in West Africa are Mali, Niger and Senegal. Cowpea cultivation is mainly under traditional systems and cowpea grain yields in farmers’ fields are low especially in the West African sub-region (0.025–0.3 t ha−1). This is caused by severe attacks of pest complexes, diseases, low soil fertility, drought, inadequate planting systems, inappropriate cultivars and lack of inputs (Ajeigbe et al., 2010a). In addition to biotic and abiotic stresses, existing planting practices limit crop yields. Despite the availability of Striga and disease-resistant cowpea cultivars, grain yields on farmers’ fields are still low. However, on-station and researcher-managed plot yields are high and encouraging. Grain yields ranging from 0.5 to 2.76 t ha−1 have been reported in sole crop (Ajeigbe et al., 2005, 2008), whereas grain yields ranging from 0.37 to 1.27 t ha−1 have been reported in intercrop in the savannahs of Africa (Ajeigbe et al., 2005, 2010b). Yield potential assumes unconstrained crop growth and adequate management that avoids limitations from nutrient deficiencies; inadequate planting systems and water stress and reductions from weeds, pests and diseases (Evans and Fisher, 1999). Considering the large differences between farmers’ yields (0.3 t ha−1) and experimental station yields (1.5–2.5 t ha−1), potential for on-farm yield increase in the region is high. This has stimulated interest in agronomic practices that could enhance crop yields. Some of the agronomic practices that may increase cowpea productivity are optimal plant population, appropriate planting date, nutrient management, integrated pest management and suitable cropping system

SSR Markers Linked with Alectra vogelii Resistance in Cowpea (Vigna unguiculata (L.) Walp)

Cowpea [Vigna unguiculata (L.) Walp.] is an important food legume grown in tropical and subtropical regions of the world, primarily in Sub-Saharan Africa. Despite the importance of cowpea, yield on farmers' field is still low due to variety of biotic and abiotic stresses that constrain its production. Among the biotic constraints, the parasitic flowering plant, Alectra voge/ii (Benth.) is one of the more formidable limitations to cowpea production in the dry Savannas of West and Central Africa, a region which accounts for over 64 % of world cowpea production. Several control measures have been suggested for the control of the parasite. These include: cultural practices, application of ethylene chemicals, and host plant resistance. Among these control measures, the use of resistance cultivars appears to be the most attractive option to the resource poor farmers in sub-Saharan Africa Breeding resistance cultivars would be facilitated by markerassisted selection (MAS). The objective of this study was to identify molecular markers tightly linked to Alectra resistance gene that would be useful in MAS in breeding cowpea for resistance to Alectra vogelii. F2 population of a single cross, Banjar (susceptible parent) x B30 I (resistant parent) was screened for reaction to Alectra using pot culture technique. DNA was extracted from parental genotypes and F2 lines from young leaves of plant at 14 days after planting using FTA ® PlantSaver cards. 50 SSR cowpea, 40 SSR rice bean and 50 SSR asparagus bean primers, previously reported to give amplification products in cowpea, were used to screen DNA from B30 I and Banjar for polymorphism. Of the 140 primers screened 20 primers were polymorphic between B30 I and Banjar and these were used in the technique of BSA performed with DNA bulks of highly resistant and highly susceptible F2 lines to select those that cosegregate with the resistant gene. Two of the markers (RB 16 from rice bean and CLM0356 from asparagus bean) were found to be consistently associated with the resistance gene. The utility of these two markers were validated using 150 F21ines for marker segregation and association analysis. Similarity index (SI) revealed that these markers were closely linked (90.23%) with Alectra resistance gene. Cluster analysis as depicted by dendogram also showed a tight association (>0.75) between these markers, suggesting that these markers can be explored in MAS targeting breeding for Alectra resistance in cowpea

Agronomic evaluation of cowpea cultivars developed for the West African Savannas

The goal of this research was to evaluate diverse cowpea genotypes developed over the past 4 decades in the Nigerian Sudan Savannas for their agronomic performance and to identify groups of cultivars with similar quantitative characters. Characterization would facilitate the efficient synthesis of breeding populations for further improvement of cowpea. Also superior genotypes with desirable characteristics could be identified and disseminated in the dry savannas of West Africa. Significant variations were observed in the agronomic characteristics of the cultivars in this study. Principal component analysis (PCA) and cluster analysis were performed on these genotypes and found that there were significant correlations among the variables measured. Modern cultivars outperformed the older ones and from the results of PCA, it was found that the most important variables for the classification of cowpea cultivars are high canopy, high seed weight, high total dry matter, high HI, and high grain and fodder yield. This suggests that these traits could be used in selection index for genetic improvement of cowpea. Cluster analysis resulted in 5 groups mostly corresponding to era of release except cluster I which contained cowpea cultivars from all eras. Two distinct groups in clusters IV and V were identified. Cultivars in cluster IV which were released in the 1990-2000 eras, had high grain and fodder yield. These cultivars could be evaluated on-farm for eventual release to farmers. They could also be used in breeding program for improvements in grain and fodder yield of cowpea. Cluster V contained two cultivars that distinctly had the highest fodder yield suggesting that they could be used to improve fodder yield of cowpea

Armed conflicts have an impact on the spread of tuberculosis: the case of the Somali Regional State of Ethiopia

<p>Abstract</p> <p/> <p>A pessimistic view of the impact of armed conflicts on the control of infectious diseases has generated great interest in the role of conflicts on the global TB epidemic. Nowhere in the world is such interest more palpable than in the Horn of Africa Region, comprising Ethiopia, Somalia, Eritrea, Djibouti, Kenya and Sudan. An expanding literature has demonstrated that armed conflicts stall disease control programs through distraction of health system, interruption of patients' ability to seek health care, and the diversion of economic resources to military ends rather than health needs. Nonetheless, until very recently, no research has been done to address the impact of armed conflict on TB epidemics in the Somali Regional State (SRS) of Ethiopia.</p> <p>Methods</p> <p>This study is based on the cross-sectional data collected in 2007, utilizing structured questionnaires filled-out by a sample of 226 TB patients in the SRS of Ethiopia. Data was obtained on the delay patients experienced in receiving a diagnosis of TB, on the biomedical knowledge of TB that patients had, and the level of self-treatment by patients. The outcome variables in this study are the delay in the diagnosis of TB experienced by patients, and extent of self-treatment utilized by patients. Our main explanatory variable was place of residence, which was dichotomized as being in 'conflict zones' and in 'non-conflict zones'. Demographic data was collected for statistical control. Chi-square and Mann-Whitney tests were used on calculations of group differences. Logistic regression analysis was used to determine the association between outcome and predictor variables.</p> <p>Results</p> <p>Two hundred and twenty six TB patients were interviewed. The median delay in the diagnosis of TB was 120 days and 60 days for patients from conflict zones and from non-conflict zones, respectively. Moreover, 74% of the patients residing in conflict zones undertook self-treatment prior to their diagnosis. The corresponding proportion from non-conflict zones was 45%. Fully adjusted logistic regression analysis shows that patients from conflict zones had significantly greater odds of delay (OR = 3.06; 95% CI: 1.47-6.36) and higher self treatment utilization (OR = 3.34; 95% CI: 1.56-7.12) compared to those from non-conflict zones.</p> <p>Conclusion</p> <p>Patients from conflict zones have a longer delay in receiving a diagnosis of TB and have higher levels of self treatment utilization. This suggests that access to TB care should be improved by the expansion of user friendly directly observed therapy short-course (DOTS) in the conflict zones of the region.</p

The Interleukin-6 inflammation pathway from cholesterol to aging – Role of statins, bisphosphonates and plant polyphenols in aging and age-related diseases

We describe the inflammation pathway from Cholesterol to Aging. Interleukin 6 mediated inflammation is implicated in age-related disorders including Atherosclerosis, Peripheral Vascular Disease, Coronary Artery Disease, Osteoporosis, Type 2 Diabetes, Dementia and Alzheimer's disease and some forms of Arthritis and Cancer. Statins and Bisphosphonates inhibit Interleukin 6 mediated inflammation indirectly through regulation of endogenous cholesterol synthesis and isoprenoid depletion. Polyphenolic compounds found in plants, fruits and vegetables inhibit Interleukin 6 mediated inflammation by direct inhibition of the signal transduction pathway. Therapeutic targets for the control of all the above diseases should include inhibition of Interleukin-6 mediated inflammation

Evaluation of multiple stress tolerant groundnut genotypes for productivity and nutritional quality in Nigeria

Groundnut plays a very important economic role for smallholder farmers in the semi-arid tropics as a major cash crop for many households; a nutritious and safe food thereby contributing to improved health of the rural population. It is rich in protein, oil and micronutrients such as iron and zinc. High iron and zinc contents are especially beneficial for women and children at risk of anemia and have proven to be genetically malleable. High oleic acid and low linoleic acid make groundnut oil ideal for storage and better human health. Evaluation of 541 advanced breeding lines along with locallandraces and improved varieties for their reaction to drought, rosette and foliar diseases besides productivity parameters over two locations during 2014 main season resulted in identification of 45 promising lines with significantly superior pod yield (1304-2796 kg/ha) compared to check entries (189-1005 kg/ha). Further, these superior genotypes were evaluated for nutritional quality and in trials during 2014115 dry season to confirm their superiority. Nutritional quality (oil, OIL ratio, protein, Fe and Zn content) analyses lead to the identification of nutritionally dense genotypes. Genotypes ICGV IS 11060, Samnut 23, ICGV 00064, ICGV 01276, ICGV IS 07827 and Kampala had high oil content (53-54%); while ICGV 07813 had high OIL ratio of 6.1 followed by ICGV IS 09992, ICGV SM 05593 and ICGV SM 06722 with 3.0 OIL ratio. Genotypes ICGV IS 07833, ICGV IS 3980, ICGV SM 08553 and rCG 5891 had high protein (30-32%), Zn (46-51 ppm) and Fe (23-34 ppm) content. These serve as ideal genetic resources to develop agronomically superior and nutritionally enhanced groundnut cultivars with multiple resistances to biotic and abiotic stresses

Legume breeding and seed systems for improved livelihoods and impact

The Tropical Legumes III project aims to reduce food insecurity in drought-prone areas of Sub Saharan Africa (SSA) and South Asia (SA), through improved productivity and production of four major grain legumes – chickpea, common bean, cowpea and groundnut. This is being sone by conducting research under three complementary research and delivery pillars: support for the development and release of farmer-preferred varieties; strengthening of the legume breeding capacity of partner CGIAR centers (ICRISAT, IITA and CIAT), and national partners Burkina Faso, Ghana, Mali, Nigeria, Ethiopia, Tanzania and Uganda; and establishment of sustainable seed delivery systems that service the needs of small-holderfarmers. Significant achievements have been recorded. Breeding program assessments have been completed in all countries and improvement plans developed for execution. New seed varieties (163) have been released and are fast replacing the old ruling seed varieties in all target countries. Thirty seven national partners were trained at MSc and PhD levels. As a result of the enhanced skills and knowledge of seed value chain actors, seed production significantly increased by 221% (from 139,048 to 446,359 tons) in seven years. Since 2007, improved varieties have been adopted on at least 2 million hectares and more than $448 million has been generated from the project funding and nearly$976 million from the project and investment partners. For each dollar invested, the project generated $9 with direct project investment or$20 with partnership’s investment, and again $20 when using adoption rate based estimate. These achievements and implementation challenges will be discussed