Agronomic Performance and Susceptibility of Seven Ghanaian Improved Sweet Potato Varieties to the Sweet Potato Weevil, Cylas spp. (Coleoptera: Brentidae) in Coastal Savanna Zone of Ghana

Depending on soil, climate and crop characteristics exposed subsoils can be amended with gypsum for agricultural activities when topsoil is inadequate as a result of natural and geophysical activities. To determine how exposed subsoil amendment with gypsum interact with weather patterns to influence soil chemical properties, cucumber growth, fruit characteristics and heavy metal concentration, a two-seasonal experiment was conducted in the major and minor rainy season of 2020 in the Ahafo-Kenyasi Mining Area in Ghana. The experiment was laid out as a 6x2 factorial arranged in randomized complete block design, consisting of 6 gypsum application rates (20 ton/ha, 40 ton/ha, 60 ton/ha, 80 ton/ha, 0 ton/ha (subsoil control) and 0 ton/ha (topsoil control)) in two rainy seasons and replicated three times. The results show that gypsum application and rainy seasons interact to significantly influence soil chemical properties, cucumber growth and fruit characteristics. Increasing gypsum application resulted in decreased organic carbon, increased calcium, increased available P, increased exchangeable magnesium (Mg), increased pH during both major and minor rainy seasons. Vine length, number of leaves, number of fruits per plant and fruit weight of cucumber were increased with increasing gypsum application during the minor rainy season. In spite of exceeding permissible limits in soils and crops, arsenic (As), cadmium (Cd) and mercury (Hg) showed similar concentrations (below 2 mg/kg) in cucumber during the minor and major rainy seasons across gypsum treatments. Lead (Pb) concentration in cucumber was significantly higher in the major season across treatments. There was no difference in lead (Pb) concentration for treated vs untreated, and no increase across the amendment range. Further studies on how heavy metals in soil and plants interact with plant phytochemicals in ecosystems and living tissues are recommended.

This study was conducted at the grasscutter section of the University of Education, Winneba, Ghana, to estimate non-genetic effects on reproductive and survival traits. Data consisted of records on 136 does from 2006 to 2010. Litter size at weaning, litter weight and lactation weight loss all increased (P < 0.01) with increasing litter size at birth. Litter weight and lactation weight loss increased (P < 0.05) at weaning, whilst days of joining decreased (P < 0.01), with increasing years. Minor rainy season was found to be the most suitable mating season. Dams that kidded in dry season took fewer (P < 0.05) days to conceive than in other seasons. Nursing dams lost more (P < 0.05) weight in dry and minor rainy seasons than in major rainy season. Increasing parity led to decreasing (P < 0.05) pre-weaning survival of offspring. Post-weaning survival of offspring decreased (P < 0.01) with increasing years. Kids conceived in the minor rainy and dry seasons had significantly higher (P < 0.05) post-weaning survival rates than those conceived in the major rainy season. Post-weaning survival rates of kids born in the minor rainy season were lower (P < 0.05) than those born in other seasons. It was concluded that non-genetic factors influenced fitness traits and must therefore be considered when designing grasscutter breeding programmes.   Key words: Domestication, environmental factors, reproduction, rodent.

Analysis of the processes that generate surface runoff and soil erosion using a short-term water budget on a mountainous sloping cropland in central Vietnam

Simple SummaryThe fall armyworm (FAW) is a serious threat to maize production in Africa following its outbreak in 2016. Fortunately, some beneficial insects that could control FAW are already present in Africa, including Telenomus remus which parasitizes FAW eggs. Telenomus remus has been used in South America for biological control of FAW for several decades. Though T. remus is already present in Africa, little is known about its potential to be used for augmentative biological control of FAW under ecological conditions and agricultural systems in Africa. This study contributed to addressing this knowledge gap by conducting replicated field release trials of T. remus for FAW control in large maize plots in Ghana. In the major and minor rainy seasons, T. remus parasitized up to 33% and 100% of FAW egg masses, respectively, in the release plots. However, similar effectiveness of T. remus was recorded in non-treated control and farmers’ plots located at 150–400 m distance from release plots, indicating high dispersion of the parasitoid. A single application of Emamectin benzoate did not significantly affect the parasitism rates of T. remus, and could be considered in IPM strategies against FAW.In response to the threat caused by the fall armyworm to African maize farmers, we conducted a series of field release studies with the egg parasitoid Telenomus remus in Ghana. Three releases of ≈15,000 individuals each were conducted in maize plots of 0.5 ha each in the major and minor rainy seasons of 2020, and compared to no-release control plots as well as to farmer-managed plots with chemical pest control. No egg mass parasitism was observed directly before the first field release. Egg mass parasitism reached 33% in the T. remus release plot in the major rainy season, while 72–100% of egg masses were parasitized in the minor rainy season, during which pest densities were much lower. However, no significant difference in egg mass parasitism was found among the T. remus release plots, the no-release control plots and the farmer-managed plots. Similarly, no significant decrease in larval numbers or plant damage was found in the T. remus release fields compared to the no-release plots, while lower leaf and tassel damage was observed in farmer-managed plots. Larval parasitism due to other parasitoids reached 18–42% in the major rainy season but was significantly lower in the minor rainy season, with no significant differences among treatments. We did not observe significant differences in cob damage or yield among the three treatments. However, the lack of any significant differences between the release and no-release plots, which may be attributed to parasitoid dispersal during the five weeks of observation, would require further studies to confirm. Interestingly, a single application of Emamectin benzoate did not significantly affect the parasitism rates of T. remus and, thus, merits further investigation in the context of developing IPM strategies against FAW.

ABSTRACTThis study sought to identify the most effective weed control methods for enhancing growth, yield and grain quality in cowpea and to reduce weed interference during the major and minor rainy seasons of 2022 at Juaso in the Asante Akim South Municipality, Ghana. Sun‐zema at 30 mL/15 L of water, Supremo (90 mL/15 L of water), Vezir (90 mL/15 L of water), Ogyama (100 mL/15 L of water) and Benfop (100 mL/15 L of water), hoeing, cutlass weeding and no weeding were evaluated in a randomized complete block design with three replicates. Data on weed flora, plant height, number of leaves per plant, days to 50% flowering and pod formation, grain yield and yield components and proximate composition of cowpea grains were collected and subjected to analysis of variance using GenStat statistical package (11th edition). Differences in means were compared using the Fisher's protected least significant difference at a probability level of 5%. Significant (p < 0.05) improvements in the growth of cowpea due to hoe weeding were observed. Hoeing, Vezir and Supremo herbicides increased grain yield during the major rainy season, with hoeing recording the highest value (0.53 ± 0.07 ton/ha), whereas Supremo herbicide recorded the highest grain yield (0.38 ± 0.06 ton/ha) during the minor season. Hoeing recorded the least grain moisture contents of 7.45 ± 0.62% and 6.35 ± 0.62% in the major and minor seasons, respectively, which could enhance postharvest handling. Application of Supremo, Sun‐zema and Ogyama reduced weed diversity in the study area. The study recommends hoeing during the major season and herbicide application (Supremo) during the minor season.

The effects of palm bunch ash (PBA) and mineral fertilizer application on grain yield and nutrient uptake in maize and soil chemical properties were studied in both the major and minor rainy seasons in the semi-deciduous forest agro-ecological zone of Ghana. In both the major and minor rainy seasons, the response of maize to four levels (0, 2, 4, and 6 tons per hectare) of palm bunch ash and 200 kg per hectare of NPK (15-15-15) application was evaluated using randomised complete block design. Results of the study showed that application of palm bunch ash significantly (P<0.05) increased soil pH, soil phosphorus, and exchangeable cations. Maize grain yield varied significantly (P<0.05) among the different treatments in both the major and minor rainy seasons. The highest maize grain yield of 4530 and 6120 kg ha-1was obtained at PBA application rate of 2 tonsha-1for the major and minor rainy seasons, respectively.

Background. The experiment was undertaken at Nsapor, a suburb of Berekum municipality in the Bono Region of Ghana, from March 2019 to November 2019 to determine the suitable rate of fertilizer nitrogen application to optimize seed yield and yield attributes of Pannar 12 and Omankwa maize varieties in a semi deciduous agroecology of Ghana. Soil fertility is low in Ghana because of factors such as rampant annual bushfires, short fallow periods as a result of high human populations, continuous cropping, deforestation, and improper mining activities. There is also little information on crop variety and site-specific fertilizer recommendations in Ghana, resulting in inappropriate use of fertilizers by most Ghanaian farmers, culminating in low crop yields. Methods. Hybrid (Pannar 12) and open pollinated (Omankwa) maize varieties were treated with four rates of fertilizer nitrogen obtained from NPK 15-15-15 (0 kgN/ha, 90 kgN/ha, 120 kgN/ha and 150 kgN/ha) and laid out in a factorial combination in a randomized complete block design with three replicates. Results. Application of 150 kg/ha of fertilizer N to Pannar 12 variety resulted in grain yields of 6146 kg/ha and 6095 kg/ha in the major and minor rainy seasons, respectively. The results also showed that application of 120 kg/ha of fertilizer N to Omankwa variety gave grain yields of 4635 kg/ha and 5286 kg/ha in the major and minor rainy seasons, respectively. To optimize the grain yield of maize, farmers could use NPK 15-15-15 fertilizer as a source of nitrogen and apply 120 kgN/ha to Omankwa variety and 150 kgN/ha to Pannar 12 variety in both major and minor rainy seasons.

Daily rainfall data are examined through the temporal analysis of various definitions of variable temporal units (VTUs) consisting of combinations of various starting dates and durations over mid-Ghana. These VTUs are independent of, yet encompass, the starting dates and durations of the major and minor rainy seasons. Within each VTU, total rainfall and number of rainy days are calculated to describe the rainfall characteristics of the unit. Means and variances of each variable are calculated for each unit over two 20-year periods, 1951–1970 (P1) and 1981–2000 (P2). In P2, the major and minor rainy seasons have undergone varying degrees of desiccation. This reduction in rainfall is, however, not temporally or spatially uniform. The widespread decline of mean rainfall totals and number of rainy days during the minor rainy season, often associated with greater inter-annual variability, is particularly threatening to the production of a second crop.

This study was undertaken to determine the effect of moringa leaf meal and season on blood and hormonal profile of the Pearl Guinea fowl (Numida meleagris) in the Middle belt of Ghana. Thirty-two (32) males and one hundred and twenty-eight (128) female Pearl Guinea fowls aged one-day-old were used for the study. A 3 x 4 factorial experimental design was used for the experiment. Data collected were analyzed using General Linear Model (GLM) procedure of Statistical Analysis System (SAS for Windows, version 7) and means were separated by the probability of difference (PDIFF) procedure of SAS (2008). Mean cell volume was highest (175.39 fl) among Guinea fowls fed with diet containing 12 % moringa leaf meal level. Guinea fowls fed with diet containing 15 % moringa leaf meal had the highest (3.44 x1012/L) red blood cells production. Eosinophil level was highest (3.95 x1012/L) among Guinea fowls fed with diet containing 9 % moringa leaf meal. Birds fed with the moringa diets recorded the highest (P= 0.022) WBC values as compared to the control diet. Triglycerides, high density lipoprotein and low-density lipoprotein levels increased (P<0.05) with increasing levels of dietary moringa leaf meal in the diet. The highest (P= 0.0025) level of progesterone was observed among birds fed with diet containing 12 and 15 % moringa leaf meal inclusion levels. The level of sodium was highest (166.69 nmol/l) among Guinea fowls fed with diet containing 12 % moringa leaf meal. The major and minor rainy seasons recorded the highest (P<0.05) mean cell hemoglobin, red blood cells, albumin and oestrogen levels. Platelets, follicle stimulating hormone, luteinizing hormone, prolactin and chlorine levels were highest (P<0.05) in the dry season while basophil level was highest in the major rainy season. Cholesterol, triglycerides, high density lipoprotein, low density lipoprotein and potassium levels were highest (P<0.05) in the major rainy season. This study concludes that feeding Guinea fowls with moringa leaf meal had positive effect on some haematological, biochemical and hormonal parameters.

Botanical insecticides are increasingly attracting research attention as they offer novel modes of action that may provide effective control of pests that have already developed resistance to conventional insecticides. They potentially offer cost-effective pest control to smallholder farmers in developing countries if highly active extracts can be prepared simply from readily available plants. Field cage and open field experiments were conducted to evaluate the insecticidal potential of nine common Ghanaian plants: goat weed, Ageratum conyzoides (Asteraceae), Siam weed, Chromolaena odorata (Asteraceae), Cinderella weed, Synedrella nodiflora (Asteraceae), chili pepper, Capsicum frutescens (Solanaceae), tobacco, Nicotiana tabacum (Solanaceae) cassia, Cassia sophera (Leguminosae), physic nut, Jatropha curcas (Euphorbiaceae), castor oil plant, Ricinus communis (Euphorbiaceae) and basil, Ocimum gratissimum (Lamiaceae). In field cage experiments, simple detergent and water extracts of all botanical treatments gave control of cabbage aphid, Brevicoryne brassicae and diamondback moth, Plutella xylostella, equivalent to the synthetic insecticide Attack® (emamectin benzoate) and superior to water or detergent solution. In open field experiments in the major and minor rainy seasons using a sub-set of plant extracts (A. conyzoides, C. odorata, S. nodiflora, N. tabacum and R. communis), all controlled B. brassicae and P. xylostella more effectively than water control and comparably with or better than Attack®. Botanical and water control treatments were more benign to third trophic level predators than Attack®. Effects cascaded to the first trophic level with all botanical treatments giving cabbage head weights, comparable to Attack® in the minor season. In the major season, R. communis and A conyzoides treatment gave lower head yields than Attack® but the remaining botanicals were equivalent or superior to this synthetic insecticide. Simply-prepared extracts from readily-available Ghanaian plants give beneficial, tri-trophic benefits and merit further research as an inexpensive plant protection strategy for smallholder farmers in West Africa.

Effective management of the fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), requires robust monitoring and surveillance in newly invaded regions. This study investigates the population dynamics and infestation levels of the FAW, Spodoptera frugiperda, on maize farms in Togo's Guinean and Sudanese climatic zones to improve pest management strategies. Male FAW moths were monitored using pheromone traps over 15 months, and larval densities and plant damage were assessed on 100 maize plants per farm. Results revealed more frequent moth captures in the Sudanese than in the Guinean climate zones (2.77 ± 0.16 vs. 2.05 ± 0.13). During the major rainy season (June to August), captures peaked in the Sudanese zone (5.28 ± 0.52) and were substantially more frequent compared to the Guinean zone (3.77 ± 0.55). No significant differences were observed during the minor rainy season (September to November), while in the dry season (December to May), captures were higher in the Guinean zone (0.54 ± 0.07) than in the Sudanese zone (0.24 ± 0.05). Despite similar larval densities, plant damage was greater in the Guinean zone during the major rainy season, likely due to positive correlations between adult captures, larval counts and plant damage in this region. Conversely, no such correlations were observed in the Sudanese zone. Additionally, maize stage‐specific analyses in Lomé and Toaga found no correlations between FAW captures, larval densities or damage. These findings highlight the need for climate‐specific pest management strategies rather than uniform national approaches, supported by linear regression models for each region.

Assessing future challenges in water resources management is crucial to the Melka Kuntrie (MK) subbasin suffering water shortage. Impact assessments are evaluated by the HBV hydrological model with six scenarios, including two GCMs of AR4-A2 and two GCMs of AR5-RCP4.5 and RCP8.5, for the time periods 2021–2050 and 2071–2100. Evapotranspiration is expected to increase under all scenarios—due to rising temperature—and induce more water stress on rainfed agriculture of the area. However, the increase in the monthly minimum temperature is beneficial to crops against chilling damages. Five out of six projections show significant increases of rainfall and streamflow in both annual and major rainy seasons, except ECHAM-A2. Annual rainfall (streamflow) is expected to increase by 38% (23%) and 57% (49%) during 2021–2050 and 2071–2100, respectively, under RCP8.5 scenarios. Greater flashflood risk is a concern because of the projected increase in streamflow. The projection of decreased streamflow with ECHAM-A2 will exacerbate the existing water shortage, especially in the minor rainy season. Water harvesting during the major rainy season would be vital to enhance water management capacities and reduce flashflood risks. Lacking sufficient hydraulic and irrigation infrastructures, the MK subbasin will be more vulnerable to the impacts of climate change.

In monoculture, crop failure due to biotic or abiotic causes can result in partial or total output failure. The yield, socio-economic, and environmental effects of intercropping on the farmer and the environment as a whole have not received much attention. There is a dearth of knowledge on the productivity of maize-groundnut intercrops in Ghana regarding the relative timing of planting and spatial arrangement of component crops. Therefore, the objective of the study was to determine the effects of spatial row arrangement and the time of planting intercrops on the productivity of groundnut under maize-groundnut intercropping. The 5 × 3 factorial field experiment was undertaken at the Miminaso community in the Ejura-Sekyedumase municipality of the Ashanti Region of Ghana during the 2020 cropping seasons. Treatments were evaluated in a Randomized Complete Block Design (RCBD) with three replicates. The levels of row arrangement of intercrops were: one row of maize and one row of groundnut (1M1G), one row of maize and two rows of groundnut (1M2G), two rows of maize and one row of groundnut (2M1G), two rows of maize and two rows of groundnut (2M2G), sole maize and sole groundnut (M/G). The levels of time of introducing groundnut included simultaneous planting of intercrops (0 WAP), planting groundnut one week after planting maize (1 WAP) and planting groundnut two weeks after planting maize (2 WAP). There were significant (P 0.05) treatment interactions for pod and seed yields of groundnut throughout the study. The highest groundnut pod yields of 1815.00 kg/ha and 2359.00 kg/ha were recorded by the 0WAP × 1M2G treatment in the major and minor seasons of 2020, respectively, while the highest groundnut seed yields of 741.00 kg/ha and 726.00 kg/ha were recorded in the major and minor rainy seasons of 2020 by 1WAP × G and 0WAP × G treatments, respectively. The highest seed yields of groundnut (404 kg/ha and 637 kg/ha for major and minor rainy seasons, respectively) were produced by 1WAP × 2M2G.

This study was conducted to investigate the effect of day length and season on haematological characteristics, biochemical and hormonal profiles of laying Guinea fowls (Numida meleagris). Four hens and 1 male were each subjected to 12 hours of light and 12 hours of darkness (12L: 12D), 14hours of light and 10 hours of darkness (14L: 10D), 16hours of light and 8 hours of darkness (16L: 8D) and 18hours of light and 6 hours of darkness (18L: 6D). Each group was replicated three times and reared in three seasons (Dry-December-March, Major rains-April-July and Minor rains-August-November) in a 3x4 factorial experiment. Data were analyzed using General Linear Model procedure of SAS. Significantly (p<0.05) higher Packed cell volume (PCV), lymphocytes and eosinophil, total serum protein and prolactin values were observed in 16L: 8D as 14L: 10D resulted in highest (p<0.05) neutrophil and albumin. PCV and Platelets were highest (p<0.05) in major rains whiles red blood cells and neutrophil were highest (p<0.05) in dry and minor rainy seasons, respectively. Total serum protein increased (p<0.05) from the dry season to minor rainy seasons. Oestrogen and luteinizing hormones were highest (p<0.05) in major rains and prolactin levels were higher (p<0.05) in minor rains and lowest in major rains. Interaction effect was not significant (p>0.05) in all parameters except prolactin. The findings of this study suggest that daylength of 14-16hrs and major rainy season in Ghana supports adequate haematological, biochemical and hormonal profiles of Guinea.

Fruiting patterns were studied for a year in lowland evergreen forest at Makokou, Gabon. Temporal patterns of fruiting were analysed according to vegetative life-form of the parent, morphological fruit type, seed dispersal mode and seed weight. In addition, fruiting cycles of 109 individuals of 13 species were monitored for two years. The results are summarized as follows : 1. Fruiting at Makokou is seasonal : fruiting peaks occur during the major rainy season and minor dry season, while the major dry season and minor rainy season are periods of fruit scarcity. A comparison with data from earlier years shows that there can be large inter-year variations in fruiting patterns. 2. There are some differences in the amplitude of fruiting seasonality depending on the parental life-form : as a group, medium-sized trees are the most strongly seasonal, emergent trees are less so. The monthly patterns of numbers individuals fruiting also differ between life-forms, as does the timing of fruiting peaks. 3. There is no clear seasonal difference in the amplitude of fruiting seasonality for different morphological types of fruits, or seed dispersal modes. Moreover, the yearly maxima in numbers of fruiting species are the same for anemochores, zoochores and autochores ; however, seasonal patterns differ depending on the fruit type (dehiscent vs indehiscent ; dull-colored fleshy fruit vs brightly-colored fleshy fruit). 4. There is no clear difference in amplitude of seasonality for fruits with different seed weights. 5. Analysis by species shows that regardless of dispersal mode, there is a complete gradient from species with strong seasonality, either annually uni-modal, or bi-modal, to those with weak seasonality and fruit production throughout most of the year. 6. Monitoring individual trees showed that among zoochorous species there can be annual, biennal or multiannual cycles, with regular, irregular or without obvious periodicity, and with fruiting synchrony or asynchrony among individuals of the same species. These results are compared to those reported for other tropical rainforests. Although we showed in a simultaneous study that there are broad suites of morphological fruit characters associated with broad categories of consumers (Gautier-Hion and al., 1985), the results presented here do not suggest an evo¬ lutionary influence of consumers on the timing of fruiting. While it is possible by selecting appropriate species subsets to suggest correlations demonstrating the influence of dispersal agents on phenology, it is likewise possible by choo¬ sing different subsets to formulate hypotheses about fruiting phenology in which coadaptation with dispersers does not play any role.