Major Rainy Season Research Articles

Eclampsia in African Milieu, Yaounde-Cameroon: epidemiology, seasonal variations and treatment regimen

Background: In our context, eclampsia is a major cause of maternal death. Patients are often sent to referral hospitals for optimal care because of the scarcity of resources in peripheral health facilities. We study characteristics of eclampsia the Yaounde Gynaeco-Obstetric and Paediatric Hospital (YGOPH) in order to prioritize our resources. Methodology: We carried out a retrospective cross-sectional descriptive study from December 2017 to April 2018 at YGOPH. All women managed for eclampsia over the preceding 10 years, from May 1st 2008 to April 30th 2018, were included in the study. We evaluated the seasons of disease occurrence, socio-demographic and clinical characteristics on admission and treatment regimen. We analysed our data using Epi info 7.0. Results: The frequency of eclampsia was 0.96% (151/25680). The mean age of patients was 23.95±6,02 years. Singles (73.5%), housewives (40.4%) and nulliparous patients (54.9%) were the most represented. The disease occurred more frequently during the major rainy season (43.7%). Patients were most often referred cases (70.2%). Eclampsia occurred mostly antepartally (70.3%). Hypertension was most often severe (83.45%). Nicardipine was the most used antihypertensive medication (76.8%) and magnesium sulphate was the anti-convulsant of choice (98.0%). The majority of women delivered by caesarean section (77.8%). HELLP syndrome was the most common maternal complication (9.9%), while prematurity was the most frequent fetal complication (58.9%). The maternal and neonatal mortality rates were 8.6% and 24.4%, respectively. Conclusion: Eclampsia remains an important cause for concern as it results in non-negligible morbidity and mortality. It is therefore important to promote and reinforce antenatal care for pregnant women while taking into consideration the seasonal variations of the disease.

Revisiting interannual to decadal teleconnections influencing seasonal rainfall in the Greater Horn of Africa during the 20th century

This paper revisits teleconnections for three major rainy seasons at the Greater Horn of Africa for the period 1901–2013. Sea surface temperature‐based climate indices known to influence Short, Kiremt, and Long Rains are used in a comprehensive statistical analysis to detect non‐stationary behaviour in teleconnections and to split them into interannual and decadal time scales. Physical mechanisms are proposed for identified significant non‐stationary teleconnections. Interannual variability in the October–December Short Rains is predominantly influenced by the Indian Ocean Dipole (IOD) with a percent variance explained (PVE) of up to 80% in recent years. However, abrupt shifts in this teleconnection occurred around 1918, 1951, 1987, and recently. The Short Rains also correlate strongly with El Niño‐Southern Oscillation (ENSO). However, ENSO influence on Short Rains is mediated by in‐phase occurrence of IOD. Decadal variations in Short Rains are more directly explained by low‐frequency variability in the Pacific Ocean (PO). A hitherto undocumented non‐stationary relation was found between Atlantic Niño 3 and June–September Kiremt Rains. The non‐stationarity seems to be related to a decadal regime shift in the West African monsoon system in the late 1960s. The variability of Kiremt Rains is also strongly associated with ENSO, although the recent increased correlation is not non‐stationary. Consistent with recent studies, the post‐1998 March–May Long Rains decline is strongly associated with decadal variability in the PO. The PVEs in the stable correlations using Pacific Decadal Oscillation and Interdecadal Pacific Oscillation indices range from 25 to 64%, mostly due to low‐frequency variability (>8 years). The results have ramifications for seasonal‐to‐decadal forecasting and can be taken to design modelling studies to gain insights into the physical mechanisms.

Evaluation of Rainfall and Temperature Conditions for a Perennial Crop in Tropical Wetland: A Case Study of Cocoa in Côte d’Ivoire

The rainfall and temperature conditions are evaluated for the first time during the 1989–2006 period, in six main cocoa production areas (Abengourou, Agboville, Daloa, Dimbokro, Guiglo, and Soubre) of Côte d’Ivoire using data from SODEXAM (ground-based observation) and the ex-CAISTAB. Statistical analysis shows an important sensitivity of cocoa production to rainfall conditions in all regions. It is worth noting that only the major rainy season from April to July and the rainfall amount of the little dry season from August to September affect the cocoa production for an 80% confidence level. This influence varies from one cacao production area to another. Moreover, the effects related to temperature on the cocoa yield seem to represent a smaller contribution of climate impact than those related to precipitation during the studied period. The temperature change remains in the acceptable range of values, between 25°C and 29°C, which is a favorable condition for cocoa growing. These findings are obtained despite the significant contributions from nonclimatic factors, to year-to-year variability in cocoa production.

El Niño‐Southern Oscillation, rainfall variability and sustainable agricultural development in the Ho Municipality, Ghana

El Niño‐Southern Oscillation (ENSO), which occurs in the Equatorial Pacific Ocean, has been identified to have significant influence on rainfall variability throughout the world, especially in the tropics. Such variability in rainfall has implications for agrarian economies, such as that in Ghana. This study therefore sought to demonstrate the effect of ENSO‐induced variability in annual and seasonal rainfall on the development of sustainable agriculture in the Ho Municipality of Ghana. Using 61 years of monthly rainfall data (1955–2015) for the Ho Municipality and ENSO indices, this study showed that 15% of the variability in total annual rainfall is explained by the ENSO phenomena. Mean annual rainfall and rainfall in the major rainy season decreased for El Niño years, in addition to a more variable rainfall compared to that received in La Niña years. The major growing season was observed to be longer in La Niña years and shorter in El Niño years. This means that the potential for crop cultivation will be severely hampered in an El Niño year. Farmers within the municipality are therefore encouraged to harness other complementary water sources for farming activities and also employ water management strategies during El Niño years.

Seroprevalence and participatory epidemiology of camelpox in Afar region of Ethiopia

Camelpox is endemic in most camel rearing regions of the world, causing significant economic losses. However, its epidemiology is not extensively investigated. We conducted a cross sectional seroprevalence study of camelpox in Amibara and Awash Fentale districts in Afar region of Ethiopia from November 2014 to May 2015. In addition, participatory epidemiology (PE) was conducted to identify seasonal occurrence of the disease in the study districts. Blood samples were collected from 384 dromedary camels from 31 herds distributed in five pastoral associations (PAs) in the two districts. Serum samples were separated from the blood samples and tested for the presence of viral antibodies using virus neutralization test. Seroprevalence data were analyzed using multilevel mixed effects logistic regression models accounting for the 4-level hierarchical data structure (camels nested in herds-herds in PA, and PA in district). For the participatory data, Kendall’s coefficient of concordance was used to assess agreements between the informants in identifying seasonal occurrences of the top five camel diseases. Camelpox antibodies were detected in 19.3% of camels (n = 384), 81% of herds (n = 31), and in all five PAs from the two districts in the Gabi Rasu zone of Afar region, Ethiopia. The seroprevalence did not significantly vary between herds, PAs or districts suggesting the widespread occurrence of the disease. Estimated age stratified basic reproduction number (R0) was 1.25 (95% CI: 0.62–2.19). Camelpox was identified as one of the top five common camel diseases in the area. The widespread occurrence of the disease can be attributed mainly to the commingling of camels from many herds during seasonal migration in search of feed and water, a practice very common under pastoral production systems. Although the PE informants indicated the clinical disease to be more common in young animals, seropositivity was higher in older animals. Camelpox commonly occurs during the minor and major rainy seasons. In conclusion, camelpox is found to be endemic in Afar pastoral region with sporadic outbreaks occurring during rainy seasons. Vaccination and improved camel management practices particularly during the high-risk period can be viable strategies to reduce the burden of the disease.

English

The aim of this study was to provide a first-hand water quality assessment of the River Nyong estuary, Southern Atlantic coast of Cameroon. Environmental variables and phytoplankton communities were monitored at four surface stations in the estuary for 2 season cycles from 2014 to 2015. A total of 208 species of phytoplankton, belonging to five (5) groups of microalgae, were identified. The Shannon-Weaver diversity index showed a qualitative seasonal difference in composition of the phytoplankton community. Dissolved nutrients (nitrogen and phosphorus) values showed seasonal fluctuations throughout the sampling period. A ratio appeared high (42.78) in the rainy season and low (5.89) in the dry season, two values corresponding to the change in specific richness (high and low respectively during the major rainy season and the small dry season). The Water Quality Index (WQI) showed that water quality fluctuates from good to bad, in conjunction with biological indicators (Shannon-Weaver, Abundance and Specific richness). Key words: Quality assessment, Nyong estuary, environmental variables, phytoplankton, water quality index.

Wet deposition of atmospheric nitrogen contributes to nitrogen loading in the surface waters of Lake Tanganyika, East Africa: a case study of the Kigoma region.

Lake Tanganyika, an African Great Lake, is a complex tropical ecosystem that has been subjected to extreme climate-related changes in the last century, including seasonal changes in temperature and rainfall, decreased overall annual rainfall, and greater frequency of rainstorms. Atmospheric nitrogen (N) is an important component of the lake's N loading, but how long-term and seasonal changes in precipitation affect this loading still needs clarification. This study aimed to improve our understanding of the seasonal features of N deposition in the lake, by monitoring atmospheric N deposition concentrations and fluxes from March 2013 to February 2014. There was a significant temporal variation in wet N depositions in the study area. The distribution of the annual rainfall into major (March-May 299.8 mm) and minor (October-December 343.2 mm) rainy seasons translated into 20 and 30% of N deposition. In September and January-February, there was 10 and 12% precipitation, representing 43 and 7% of N deposition in the lake. Nitrogen deposition was highest in September due to farmlands' burning during the dry season (June-August), leading to N accumulation in the atmosphere. In conclusion, the pattern of N deposition appears to be driven by the unique climatic characteristics of the lake basin and to be closely associated with local anthropogenic activities.

Impacts of Changing Climate on Maize Production in the Transitional Zone of Ghana

This study sought to assess the challenges and opportunities that come with climate change and variability impacts on maize farming in the Nkoranza South Municipality in the Transitional Zone of Ghana. The mixed method approach (qualitative and quantitative) was used in collecting the data. Rainfall data obtained from the Ghana Meteorological Agency (GMet) indicated that the dry cell between the major and minor rainy seasons was getting wetter and the two seasons were gradually merging whereas the first and last quarters of the year were getting drier over the last couple of decades. The situation over the last five years (2010-2015) had worsened as the amount of total rainfall had reduced by 22% compared to the 30 year period between 1960 and 1982. The results of the study showed that farmers had perceived changes in climate in the form of decreasing rainfall, rising air temperatures and seasonal changes in rainfall pattern which were affecting their maize farming operations. The major setbacks within the area were deficit in rainy days and intermittent erratic rainfall affecting maize production. The major opportunity available to farmers in the face of changing climate in this agroecological zone was cashew production. About 76.8% of the respondents had diversified into cashew farming as a result of rainfall failure and strong resistance of the cashew trees to changing and variable climate.

Burden of influenza among hospitalized febrile children in Ghana.

BackgroundInfluenza surveillance data from Africa indicate a substantial disease burden with high mortality. However, local influenza data from district hospitals with limited laboratory facilities are still scarce.ObjectivesTo identify the frequency and seasonal distribution of influenza among hospitalized febrile children in a rural hospital in Ghana and to describe differential diagnoses to other severe febrile infections.MethodsBetween January 2014 and April 2015, all children with a temperature of ≥38°C admitted to a district hospital in Ghana were screened for influenza A and B by RT‐PCR and differentiated to subtypes A(H1N1)pdm09 and A(H3N2). Malaria microscopy and blood cultures were performed for each patient.ResultsA total of 1063 children with a median age of 2 years (IQR: 1‐4 years) were recruited. Of those, 271 (21%) were classified as severe acute respiratory infection (SARI) and 47 (4%) were positive for influenza, namely 26 (55%) influenza B, 15 (32%) A(H1N1)pdm09, and 6 (13%) A(H3N2) cases. Influenza predominantly occurred in children aged 3‐5 years and was more frequently detected in the major rainy season (OR = 2.9; 95% CI: 1.47‐6.19) during the first half of the year. Two (4%) and seven (15%) influenza‐positive children were co‐diagnosed with an invasive bloodstream infection or malaria, respectively.ConclusionInfluenza contributes substantially to the burden of hospitalized febrile children in Ghana being strongly dependent on age and corresponds with the major rainy season during the first half‐year.

Aspects of reproduction of the brown mussel Perna perna at the Iture rocky beach near Cape Coast, Ghana

Aspects of the reproductive biology of the brown mussel Perna perna at the Iture rocky beach near Cape Coast, Ghana, were studied from September 2014 to August 2015. The current study was aimed at providing information useful for managing the mussel fishery in this locality and also that would form the basis for designing appropriate culture methods for the species. Microscopic examination of fresh smears of gonadal material, as well as histological preparations of the gonad, were used to study the sexuality and breeding pattern of the species. Monthly gonadal and condition indices were also determined. Perna perna exhibited gonochoristic sexuality with a sex ratio of approximately 1:1 throughout the study period. Sexes were identifiable at shell lengths of 15.0–19.9 mm. Five stages of gonadal development were identified in both sexes. Gametogenic activity was continuous throughout the year, with two major spawning activities, from April to June and from August to December. These periods coincided with the major and minor rainy seasons, respectively, as well as the major upwelling period in August. Condition indices suggest that the mussels were in better condition for harvesting in March and August prior to the major spawning events.

Improving maize production through nitrogen supply from ten rarely-used organic resources in Ghana

Where there is limited availability of conventional fertilizers, the use of organic materials is considered a viable alternative to increase the productive capacity of soils. Many potential plant residues remain underutilized due to limited research on their use as a nutrient source. In this study, the nitrogen supplying capabilities of ten rarely-used leaf biomass sources (Acacia auriculiformis, Baphia nitida, Albizia zygia, Azadirachta indica, Senna siamea, Senna spectabilis, Tithonia diversifolia, Gliricidia sepium, Leucaena leucocephala and Zea mays) were tested based on their nutrient content, N mineralization patterns and effect on maize yield (in comparison with inorganic fertilizer). N mineralization was studied in the laboratory using an incubation experiment. Field trials were also established using a randomized complete block design. Plant residues were applied at 5 t dry matter ha−1 a week before planting maize while fertilizer was split-applied at 90 kg N ha−1 on designated plots. From the results on plant residue chemistry, most of the plant residues recorded relatively high N concentration (≥24.9 g kg−1) and low C/N ratio (≤20.1) although neither N content nor C/N ratio significantly (p > 0.05) affected their N mineralization patterns. Leaf biomass application of B. nitida, A. auriculiformis, A. zygia and maize stover resulted in an initial net N immobilization that lasted for 14 days. Application of all plant materials significantly increased the biological yield and N uptake of maize with G. sepium and T. diversifolia producing the greatest impact especially in the major rainy season. Relative to the control, total grain yield after four cropping seasons was comparable between inorganic fertilizer (9.2 t ha−1), G. sepium (8.8 t ha−1) and T. diversifolia (9.4 t ha−1) treatments. The results on maize biological yield were significantly correlated with the effects of the treatments on N uptake. The findings suggest that in locations where inorganic fertilizers are limited, leaf biomass from G. sepium and T. diversifolia could offer the most suitable option in comparison with the other species used in this study.

Evaluation of a climate change-adaptive, eco-friendly agronomic package for potato (<em>Solanum tuberosum</em> L.) cultivation in the farmer fields of the Jaffna district of Sri Lanka

Potato is one of the key annual upland cash crops cultivated in the Jaffna District of Sri Lanka. However, potato farmers are challenged by climate extremes, increasing pest/disease loads and excessive use of agro-chemicals all of which are expected to increase in the future. To address these critical issues, a package of climate changeadaptive and eco-friendly agronomic practices that included mulching to conserve soil moisture, integrated pest management for crop protection and site-specific fertilizer management for efficient crop-soil nutrient management (adaptation package) was formulated and tested on potato ( Solanum tuberosum L.) crops in seven farmer fields in Jaffna. The experiment was conducted in the major rainy season (Maha) of 2013/2014 and 2014/2015 and consisted of two treatments as Adaptation package (T 1 ) and Existing practice (T 2 ), which is the current farmers’ practices characterized with heavy reliance on chemical control of pests and diseases and application of inorganic fertilizers subsequent to decisions of farmer. The results revealed significant (p<0.05) benefits of the above climate changeadaptive, eco-friendly agronomic package in terms of growth, yield, economic profit and environmental health of potato cultivation. Benefits of the adaptation package were greater in the drier and warmer 2014/15 Maha season, thus demonstrating its climate resilience. Therefore, the tested adaptation package can be recommended for adoption by the farmers to improve the yield of potato while promoting lower water and agro-chemical use thereby having increased resilience to climate change and improved environmental sustainability especially in the dry regions where potato is cultivated.

ESTRUCTURA DE LA COMUNIDAD DE ZOOPLANCTON EN CONDICIONES DE DESCARGA CONTINENTAL Y DE AFLORAMIENTO COSTERO EN SANTA MARTA, CARIBE COLOMBIANO

Variation in the taxonomlc and trophic structure of the zooplankton community, associated to fertilizations alternating between continental runoff and coastal upwelhng. were studied in the nenttc province of the Santa Maria area. Colombian Caribbean Sea. Sampling was carried out In November 1991 during the major rainy season, and in April 1992 during the dry season. Organisms were Identified, counted and trophically placed, and the biomass por trophic levo! was dotorminod. Eighty-two spocies-taxa were discriminated, most ot them oceaniccoastal and predominantly omnrvores. Community composition varied temporally and spatially with predominant oceanographic conditions, evidoncmg succossional procossos rotatod to fertilization pulses. During continental runoff conditions, typical of the rainy season, community composition and total biomass and abundance were spatially more heterogeneous, with species more coastal and neritic, large omnivores and detritivores and small carnívoros. Dunng upwellmg conditions, which occur as localizod pulses during the rainy season, and generalize throughout the study area during the dry season, the community was spatially more homogeneous, with spocies more ocoanic and doop-dwolhng and. in its maximum development, with higher biomasses. omnivores and detritivores small, and greater representation and size of macrofiltering herbivores and carnivores.

Exploiting the Insecticidal Potential of the Invasive Siam Weed, Chromolaena odorata L. (Asteraceae) in the Management of the Major Pests of Cabbage and their Natural Enemies in Southern Ghana

Cabbage is an important leafy vegetable widely cultivated and consumed in Ghana. It offers a good source of vitamins and minerals to the human body. Despite its importance cabbage production is constrained by insect pests attack. Chemical control has being the main strategy, but without much success, thus the need for alternative options for pest management. Field experiments were conducted in the major and minor rainy seasons of 2014 to evaluate the insecticidal potential of Siam weed, ChromolaenaodorataL. at three concentrations (10, 20 and 30 g/L w/v) in the management of the key pests of cabbage and its effect on their natural enemies. Neem seed extract (50 g/L) and Lambda cyhalothrin (Sunhalothrin® 2.5 ml/L) were used as reference insecticides with tap water as a control. The key pests recorded during the major season were the cabbage aphid, Brevicorynebrassicae, and cabbage webworm, Hellulaundalis, whiles Diamondback moths (DBM), Plutellaxylostellaand B. brassicaewere recorded in the minor season. Generally, the three concentrations of C. odoratawere efficacious in controlling aphids and DBM than the tap water and conventional insecticide, Sunhalothrin® in both the minor and major seasons. However, the 10 and 20 g/L C. odoratarecorded the highest buildup of natural enemy populations and also had higher yield as compared to 30 g/L C. odorata, Sunhalothrin®, and tap water. The cabbage plots sprayed with neem obtained the highest yield

Environmental Pollution Bioindication Based on &amp;lt;i&amp;gt;Ficus benjamina&amp;lt;/i&amp;gt; L. Leaf Reflectance in the City of Abidjan, C&amp;#244;te d’Ivoire

The air in African cities is increasingly polluted mainly due to human activities. A bioindication technical of urban air quality based on active remote sensing might be an alternative to existing physico-chemical methods. Reflectance measurements in the visible spectrum have been carried out at the adaxial and abaxial sides of Ficus benjamina L. leaves in the city of Abidjan, C&#244te d’Ivoire, with a precision digital camera. Leaves were collected in industrial zones and in parks. The impact of air pollution on leaf physiological as well as structural characteristics in these two contrasts urban environments was determined by Dorsiventral Leaf Reflectance Correlation (DRLC) and dorsiventral leaf reflectance asymmetry quantitatively defined with Normalized Dorsiventral Asymmetry Index (NDAI). Species leaf susceptibility to air pollution from season to season was determined by NDAI seasonal variation. Leaf reflectance measurements allowed the estimation of environmental stress level among industrial areas and parks. NDAI and DLRC were significantly higher in industrial zones compared to parks. NDAI values were found significantly higher for major rainy season compared to major dry season, indicating probably that F. benjamina leaf structure changes were increased from one season to another. Thereby, assessment of urban air quality can be done using leaves reflectance in the visible spectrum.

Aligning Sowing Dates with the Onset of Rains to Improve Rice Yields and Water Productivity: Modelling Rice (Oryza sativa L.) Yield of the Maha Season in the Dry Zone of Sri Lanka

Rice (Oryza sativa L. ) cultivation in Sri Lanka is restricted by limited water availability. Increased variability of seasonal rainfall as a result of climate change will further exacerbate risk in rice cultivation. Knowing the onset of rainfall through forecasts, adjusting planting date based on the predicted rainfall onset, and efficient irrigation management are important determinants to reduce the risk in rice farming. In this study, a modelling approach was used to assess the yield advantage of changing planting dates according to the onset of seasonal rainfall compared to a fixed planting date in the major rainy season (Maha), and evaluated the efficiency of irrigation management. The model, Agricultural Production Systems Simulator (APSIM), was parameterized using data from the literature, and the model could simulate the observed yield of rice varieties Bg300 and Bg359 with a good fit (CV Tropical Agricultural Research Vol. 25 (3): 277-286 (2014)

Growth and Yield Responses of Soybean to Climate Change

In recent years, soybean [Glycine max (L.) Merrill] has emerged as a major rainy season cash crop in central India. In the present study, the changes in soybean scenario over a period from 2001 to 2013 of Indore district and Madhya Pradesh since 1980 with respect to area sown, production, and productivity are discussed, taking in consideration the changes in climatic variables like rainfall and temperature during the corresponding period. The data related to area, production, and yield of soybean from 2001 to 2013 of Indore district, Madhya Pradesh since 1980, and India were collected from published work. To observe yield changes across seasons, the means of the yield were plotted against the seasons. It was observed that in last 10 years, there is a shift in the peak rainfall from July to August, and the total rainfall during the peak month was reduced. The rainfall during the emergence and vegetative growth of the soybean crop has been reduced. However, the soybean productivity has increased with 21.6 and 13.9 kg/ha/year in Indore district and in Madhya Pradesh, respectively. Release of new cultivars and improvements in farming technology have contributed to this continuous increase in soybean yield. A few studies showed that potential adaptation options for sustained soybean productivity in India include adjustment in cropping calendar and crop rotation, development and promotion of use of high yielding varieties, and sustainable technological applications. Delayed sowing date for soybean crop at all locations in India should be most effective in mitigating the thermal effects of climate change.

The Annual Cycle of East African Precipitation

Abstract East African precipitation is characterized by a dry annual mean climatology compared to other deep tropical land areas and a bimodal annual cycle with the major rainy season during March–May (MAM; often called the “long rains”) and the second during October–December (OND; often called the “short rains”). To explore these distinctive features, ERA-Interim data are used to analyze the associated annual cycles of atmospheric convective stability, circulation, and moisture budget. The atmosphere over East Africa is found to be convectively stable in general year-round but with an annual cycle dominated by the surface moist static energy (MSE), which is in phase with the precipitation annual cycle. Throughout the year, the atmospheric circulation is dominated by a pattern of convergence near the surface, divergence in the lower troposphere, and convergence again at upper levels. Consistently, the convergence of the vertically integrated moisture flux is mostly negative across the year, but becomes weakly positive in the two rainy seasons. It is suggested that the semiarid/arid climate in East Africa and its bimodal precipitation annual cycle can be explained by the ventilation mechanism, in which the atmospheric convective stability over East Africa is controlled by the import of low MSE air from the relatively cool Indian Ocean off the coast. During the rainy seasons, however, the off-coast sea surface temperature (SST) increases (and is warmest during the long rains season) and consequently the air imported into East Africa becomes less stable. This analysis may be used to aid in understanding overestimates of the East African short rains commonly found in coupled models.

English

Cowpea is well adapted to environmental conditions that affect crop production such as drought, high temperatures and other biotic stresses compared with other crops. Notwithstanding, growth and development of many cowpea cultivars are affected by drought and high temperatures, especially during floral development. This is because cowpea cultivars tend to have narrow range of adaptation as cultivars developed for one zone usually are not very productive in other zones. A study on the yield and growth performance of seven cowpea varieties was conducted during the 2012 major and minor rainy seasons at the CSIR-Crops Research Institute, Kwadaso-Kumasi, Ghana to compare the performance of the seasonal variation on each variety. These improved varieties Nhyira, Tona, Asetenapa, Asomdwe, Hewale, Videza and IT 89KD374-57 were evaluated using a randomized complete block design and replicated three times. The results showed that varieties Hewale, Videza and Nhyira gave higher seed yields, whereas IT 89KD374-57 and Asetenapa had lower seed yields. Nhyira and Hewale gave comparatively better seed yields under both conditions. Hewale was the highest seed-yielding genotype under both major and minor raining season. Cowpea production could be a profitable agribusiness for cowpea growers in Ghana considering the higher returns in terms of grain yield obtained in both seasons. &nbsp; Key words: Cowpea, agronomic performance, improved varieties.

Growth and Yield Performance of Improved Cowpea (Vigna Unguiculata L.) Varieties in Ghana

Cowpea is well adapted to environmental conditions that affect crop production such as drought, high temperatures and other biotic stresses compared with other crops. Notwithstanding, growth and development of many cowpea cultivars are affected by drought and high temperatures, especially during floral development. This is because cowpea cultivars tend to have narrow range of adaptation as cultivars developed for one zone usually are not very productive in other zones. A study on the growth and yield performance of seven cowpea varieties was conducted during the 2012 major and minor rainy seasons at the CSIR-Crops Research Institute, Kwadaso-Kumasi, Ghana to compare the performance of the seasonal variation on each variety. These improved varieties Nhyira, Tona, Asetenapa, Asomdwe, Hewale, Videza and IT 89KD374-57 were evaluated using a randomized complete block design and replicated three times. The results showed that varieties Hewale, Videza and Nhyira gave higher seed yields, whereas IT 89KD374-57 and Asetenapa had lower seed yields. Nhyira and Hewale gave comparatively better seed yields under both conditions. Hewale was the highest seed-yielding genotype under both major and minor raining season. Cowpea production could be a profitable agribusiness for cowpea growers in Ghana considering the higher returns in terms of grain yield obtained in both seasons.