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The evolution of resistance to the Bacillus thuringiensis (Bt) toxins by insect pests is a major threat to Bt technology. However, the rate of resistance can be slowed with appropriate integrated insect resistance management (IRM) strategies. Surveys were conducted to identify alternate host species for Maruca vitrata (commonly called the legume pod borer or Maruca) that could serve as refuges for Pod-Borer Resistant (PBR) cowpea in three West African countries (Ghana, Nigeria, and Burkina Faso). Survey sites included 25 in northern Ghana, 44 in northern Nigeria, and 52 in north-central and southwestern Burkina Faso. Alternate hosts of Maruca identified from plant species belonging to the Fabaceae family that showed signs of Maruca damage on cowpea tissues were collected and dissected. Larvae that were found during these dissections were reared to adult moths in the laboratory then identified to species. The alternate host plants including species of Crotolaria, Sesbania, Tephrosia, and Vigna were the most frequently encountered among sites and locations. Flowering and podding of these plants overlapped with flowering and podding of the nearby (~200 m) cowpea crop. Abundance of these wild hosts and overlapping flowering patterns with the cowpea crop in most locations have the potential to sustain ample numbers of Bt susceptible Maruca that will mate with possible resistant Maruca and deter resistance development. Further quantitative studies, however, are required from each location to determine if actual Maruca production from alternate hosts is sufficient for a PBR IRM strategy. If verified, this approach would be compatible with the high dose/refuge IRM strategy that includes alternate hosts and non-Bt crops as refuges.

Peanut (Arachis hypogaea L.) yield and financial returns are often low for smallholder farmers in Ghana. Additionally, aflatoxin concentration in foods derived from peanut can be high enough to adversely affect human health. Eight experiments were conducted in 2016 and 2017 in northern Ghana to compare yield, financial returns, pest reaction, and aflatoxin contamination at harvest with traditional farmer versus improved practices. Relative to the farmer practice, the improved practice consisted of weeding one extra time, applying local potassium-based soaps to suppress arthropods and pathogens, and application of either homogenized oyster shells or a commercial blend of fertilizer containing calcium. Each of these field treatments were followed by either drying peanut on the soil surface and storing in traditional poly bags or drying peanut on tarps and storing in hermetically-sealed bags for 4 months. Peanut yield and financial returns were significantly greater when a commercial blend of fertilizer or oyster shells were applied compared to the farmer practice of not applying any fertilizer. Yield and financial returns were greater when a commercial fertilizer blend was applied compared with oyster shells. Severity of early leaf spot [caused by Passalora arachidicola (Hori) U. Braun] and late leaf spot [caused by Nothopassalora personata (Berk. & M.A. Curtis) U. Braun, C. Nakash., Videira & Crous], scarring and penetration of pods by arthropods, and the number of arthropods at harvest were higher for the farmer practice than for either fertility treatment; no difference was noted when comparing across fertility treatments. Less aflatoxin was observed for both improved practices in the field compared with the farmer practice. Drying peanut on tarps resulted in less aflatoxin compared to drying peanut on the ground regardless of treatments in the field. Aflatoxin concentration after storage was similar when comparing post-harvest treatments of drying on soil surface and storing in poly bags vs. drying on tarps and storing in hermetically-sealed bags. These results demonstrate that substantial financial gain can be realized when management in the field is increased compared with the traditional farmer practice. While aflatoxin concentrations differed between the farmer practice and the improved practices at harvest and after drying, these differences did not translate into differences after storage.

Aflatoxin in peanut (Arachis hypogaea L.) and other crops can negatively affect human health, especially in countries where regulatory agencies do not have limits on aflatoxin entering the food supply chain. While considerable research has been conducted addressing aflatoxin contamination in peanut at individual steps in the supply chain, studies that quantify aflatoxin contamination following combinations of interventions to crop management, drying, and storage are limited. Research was conducted during 2016 and 2017 in two villages in southern Ghana to follow aflatoxin contamination along the supply chain and to compare improved practices with traditional farmer practices used by smallholders. The farmer practice of only a single weeding was compared with improved practices during the growing season up to harvest that included applying local soaps to suppress aphids (Aphis gossypii Golver) that transmit peanut rosette virus disease (Umbravirus: Tombusviridaee), one additional weeding, and calcium applied at pegging. The improved practice for drying included placing pods removed from plants onto tarps compared with the traditional practice of drying on the ground. Storing peanut for four months in hermetically-sealed bags was the improved practice compared with storing in traditional poly bags. All improved practices individually resulted in lower aflatoxin contamination as compared to the farmer practices. While aflatoxin levels were very low (

Cowpea [Vigna unguiculata (L) Walp.] is an important staple legume in the diet of many households in sub-Saharan Africa. Its production, however, is negatively impacted by many insect pests including bean pod borer, Maruca vitrata F., which can cause 20–80% yield loss. Several genetically engineered cowpea events that contain a cry1Ab gene from Bacillus thuringiensis (Bt) for resistance against M. vitrata were evaluated in Nigeria, Burkina Faso, and Ghana (West Africa), where cowpea is commonly grown. As part of the regulatory safety package, these efficacy data were developed and evaluated by in-country scientists. The Bt-cowpea lines were planted in confined field trials under Insect-proof netting and artificially infested with up to 500 M. vitrata larvae per plant during bud formation and flowering periods. Bt-cowpea lines provided nearly complete pod and seed protection and in most cases resulted in significantly increased seed yield over non-Bt control lines. An integrated pest management strategy that includes use of Bt-cowpea augmented with minimal insecticide treatment for protection against other insects is recommended to control pod borer to enhance cowpea production. The insect resistance management plan is based on the high-dose refuge strategy where non-Bt-cowpea and natural refuges are expected to provide M. vitrata susceptible to Cry1Ab protein. In addition, there will be a limited release of this product until a two-toxin cowpea pyramid is released. Other than South African genetically engineered crops, Bt-cowpea is the first genetically engineered food crop developed by the public sector and approved for release in sub-Saharan Africa.

Insecticide application is the recommended practice for control of insect pests on cowpea (Vigna unquiculata (L) Walp). However, these have negative effects on humans and the environment, apart from being costly for resource-poor farmers. This study aimed at identifying appropriate combinations of cultivar and insecticide spraying times for the management of economically important insect pests of cowpea in northern Ghana. The study was conducted in two successive rainy seasons at two locations situated in the Sudan and Guinea Savannah zones of northern Ghana. The experimental layout was a complete randomized split plot design with main-plots consisting of different numbers and timing of insecticide application and sub-plots consisting of 6 different cowpea cultivars. Data collected included insect pest abundances, components of yield and yield. Thrips (Megalurothrips sjostedti Trybom), legume pod borer (Maruca vitrata Fabricius) and a complex of pod-sucking bugs (PSBs) were the dominant insect pests. Their abundance and damage were not significantly different between the untreated control and cowpea sprayed once at 50% flowering stage. In contrast, protecting cowpea with either two (i.e., flower bud initiation and early podding) or three rounds of insecticide sprays (i.e., bud initiation, 50% flowering and 50% podding) significantly lowered insect pest abundance and increased grain yield. Apart from the farmer's cultivar which was susceptible to pest attacks, the improved ones showed variable levels of tolerance to the different pest categories. Combining at least two rounds of insecticide sprays with any improved variety suppressed pest populations and increase cowpea grain yield. Keywords: Cowpea, Insecticide treatments, Savannahs, Yield, Damage levels, Integrated pest management

New technologies combined with improved genetics and farmer access are important components required to improve productivity and efficiencies of cropping systems. The ability of the public and private sector to provide these components to farmers often vary considerably and can be challenging because of limited resource allocation and investment in institutions designed to provide these services. Partnerships among national programs where resources are limited and external entities can provide an effective platform to deliver improved cultivars and production and pest management practices that increase crop yield and economic viability of resource-poor farmers. In this note, we describe a partnership between the Council for Scientific and Industrial Research-Crops Research Institute (CSIR-CRI) in Ghana, the International Center for Research in the Semi-Arid Tropics (ICRISAT), the US Agency for International Development Peanut Collaborative Research Support Program (USAID Peanut CRSP), the Feed the Future Innovation Lab on Peanut Productivity and Mycotoxin Control (PMIL), and North Carolina State University (NCSU) that resulted in the release of two ICRISAT-derived lines as cultivars to farmers in Ghana. The cultivars Otuhia (Arachis hypogaea L.) and Yenyawoso (Arachis hypogaea L.) were released by CSIR-CRI in 2012 following evaluations of breeding lines beginning in 1999. This case study provides insight into the research focus and timeline that occurred with this partnership during the research and development process. A portion of the data obtained to support release of these cultivars is provided.

This study evaluated grain yield performance, stability and agronomic nitrogen-use efficiency (AE) of twelve maize populations under three nitrogen (N) rates at two locations in the Guinea and Sudan savannah zones of Ghana in 2014 and 2015. The N rates used were 0, 30, and 90 kg N ha−1. Computations were made for grain yield and AE. Populations × nitrogen interactions were significant for grain yield and AE at the three N rates. The mean yield of the populations under 0, 30, and 90 kg N ha−1 were 1.42, 4.12, and 6.80 t ha−1, respectively. Mean AE of the populations under low-N and high-N was 90.34 and 59.73 kg kg−1, respectively. Populations LNP-Syn-W, TZPB-LN-Syn and IWD-C2-Syn-F2 were efficient under both low-N and high-N inputs and produced 229.17 kg ha−1 and 572.5 kg ha−1 more grains than the average yield of all the populations under low-N and high-N, respectively. The results of this study indicated that the highest response to selection of N-efficient maize populations is achieved under low-N when the grain yield reduction at low-N is 39% of those of high-N environments. Keywords: Grain yield stability, Low soil nitrogen, Nitrogen use efficiency, Genotype × nitrogen interaction

Soybean cultivation in Ghana is on a rapid increase because of its importance as food and cash crop. However, its production is constrained by pod-sucking insects that attack the pods and seeds. Field studies were conducted to deterimine the effect of planting date and cultivar on pod-sucking bug (PSB) infestation and yield of soybean. Four soybean varieties, four planting dates and two insecticide spraying regimes were evaluated. The results showed that soybean planted early (i.e. mid-June) suffered less PSB attack resulting in low seed damage and high yields. This suggests that mid-June is the best period to plant soybean to avoid PSBs for maximum yields in northern Ghana. Planting should be completed by mid July to avoid poor yields. The genotypes TGX 1799-8F and TGX 1834-5E consistently suffered less insect attack and can therefore be incorporated in an IPM package because of their relative resistance to insect pests. Keywords: Glycine max (L.) Merrill, Host plant resistance, Pod sucking bugs, Planting date, Insecticide control, Integrated pest management

Insect pests are a major constraint to cowpea production in northern Ghana where it is widely cultivated. Field experiments were conducted to evaluate the effects of planting date, cultivar and insecticide applications for the management of major insect pests attacking cowpea. There were 4 planting dates, 6 cowpea cultivars of medium maturity periods and 2 insecticide spraying regimes. Data were collected on densities of the major insect pests, including the legume pod borer Maruca vitrata F., thrips Megalurothrips sjostedti Trybom, and the pod-sucking bug complex dominated by Clavigalla tomentosicollis Stal., and grain yield. Early planting of cowpea in mid- or late July resulted in the lowest pest densities compared with those planted at later dates. Two of the six cowpea varieties (IT99-573-2-1 and IT99-573-1-1) supported the lowest numbers of insects across planting dates and irrespective of insecticide spraying regime. However, insecticide sprays significantly lowered pest densities and improved yields in all varieties, and yields were the highest when treatments were combined with early planting in mid-July. The results suggest that for maximum yield, cowpea in the study area should be planted in mid-to-late July and sprayed with insecticide. Where available, these treatments can also be integrated with varieties such as IT99K-573-2-1 and IT99k-573-1-1 which appeared to be less susceptible to insects in the current study.

Weeds and diseases can reduce peanut (Arachis hypogaea L.) yield or increase cost of production to maintain acceptable yield. While herbicides and fungicides have limited availability in many areas...

SUMMARYLarvae of bollworms (Helicoverpa armigera (Hubner), Earias sp., Diparopsis watersii (Rothschild) and Pectinophora gossypiella (Saunders)) feed on cotton flower buds (squares) and developing bolls causing severe yield losses. While endosulfan, an organochlorine insecticide was the most effective and widely used insecticide for bollworm control in Ghana, it has been banned due to abuse and hazard to the environment. Field experiments were conducted during the rainy seasons of 2012 and 2013 to determine the efficacy of foliar insecticides tihan (spirotetramat + flubendiamide), thunder (imidacloprid + betacyfluthrin), belt expert (flubendiamide +thiaclopride), dursban 4EC (chlorpyrifos-ethyl), lambda super 2.5EC (lambda cyhalothrin) and polytrin C (profenophos + cypermethrin) for control of bollworms and their impact on non-target beneficial organisms in Ghana. All the insecticides tested lowered bollworm densities and boll damage but applications of tihan or belt expert alternated with thunder resulted in the highest seed cotton yield. The treatments generally did not lower populations of predators such as ladybird beetles and lacewings and could be included in an integrated pest management programme for bollworms in cotton. These results suggest that alternate applications of tihan or belt expert with thunder can be recommended as a replacement for endosulfan for control of cotton bollworms and improvement of cotton yield in Ghana.

Participatory diagnostic farmer field fora (FFF) were conducted at two communities, Savelugu and Bukpomo, in northern Ghana to build the capacity of farmers on integrated pest management in cowpea production. The FFF involved a season-long comparative evaluation of farmers’ practices (FP) and integrated pest management (IPM). Farmers’ practices relied wholly on calendar insecticide sprays while IPM plots employed proven agronomic practices and treatment with neem (Azadirachta indica A. Juss) extract for insect pest control. Results showed that insect pest densities (Flower thrips, Megalurothrips sjostedti Trybom and pod-sucking bugs’ for example, Clavigralla tomentosicollis Stal.) and percent damaged pods as well as grain yield were similar in FP and IPM plots at both Savelugu and Bukpomo. Partial budget analysis showed positive returns to investment in IPM and a near loss in FP. Post training ballot box test showed that 80% of the farmer participants across locations showed improved knowledge and skills in IPM after the training compared with about 30% before the training. An ancillary study to the FFF was conducted to expose the farmers to different cowpea genotypes in a participatory variety selection trial. Results showed that some of the genotypes selected by farmers as their most preferred genotypes at the vegetative stage were also selected at the podding stage but there were no significant correlations between these farmer preferences and yield. These findings are discussed in the context of sustainable cowpea production through farmer empowerment and involvement in technology generation and dissemination. Key words: Farmer field fora, participatory variety selection, cowpea, Azadirachta indica.

Fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith), was first detected in Africa in 2016. Efforts at controlling it have been challenged by the many unknowns about this invasive insect. The population dynamics of FAW moths and the damage caused by the larvae were studied in maize fields over two successive seasons in northern Ghana. Pheromone traps were deployed in sole maize fields located in Northern (NR), Upper East (UER) and Upper West (UWR) regions to assess male moth population over time. Data on damage to maize by the larvae as well as climatic variables were also recorded. A total of 2601 FAW moths were captured over the two seasons from the three regions. In general, catches increased steadily from time of emergence (i.e., 12.2 ± 1.4 and 14.4 ± 2.6 moths in July 2017 and 2018, respectively) and peaked when the plants were growing into the reproductive stage (i.e., 13.9 ± 2.2 and 56.0 ± 14.9 moths in August 2017 and 2018, respectively); afterwards catches declined significantly. There were no significant differences between regions in both years for mean their moth catches. Damage to maize was significantly higher in 2017 (4.8 ± 0.4) than in 2018 (2.4 ± 0.3) (P = 0.005). This variable correlated positively with FAW larval abundance. Rainfall was the only climatic variable that influenced moth abundance significantly and positively in all three regions in both years; except for 2018 in UER. Thus, management of FAW in northern Ghana and locations with similar agro-ecologies must be from emergence to the tasselling stage, as well as periods of increased precipitation.

Field efficacy of neem (Azadirachta indica A. Juss) for managing soil arthropods and Cercospora leaf spots damage to peanut was studied in Ghana from 2008 to 2010. Treatments consisted of neem kernel water extract (NKWE) and neem kernel powder (NKP) applied separately as soil drench at the rates of 10.5 and 21.0 kg/ha at either planting or pegging. Untreated control and chlorpyrifos treatment at pegging were included as checks. Results showed generally that the neem products at the concentrations tested were efficacious and comparable to chlorpyrifos in lowering populations of soil arthropods and severity of leaf spot diseases, leaf defoliation, and scarified and bored pod damage, resulting in increased pod yield in 2008 and 2009

Aflatoxins contamination in peanut seeds remains a major challenge in Ghana. This study evaluated aflatoxin levels in peanut samples from farmer storage units, and participatory on-farm research trials. In all, 240 respondents were covered from six main producing districts in northern Ghana through a multi-stage sampling approach. Samples were analysed for total aflatoxins using the indirect Enzyme Linked Immunosorbent Assay technique. Overall, total aflatoxins in the farmer stored nuts showed wide variations across communities and districts. At 20 ppm permissible level, 92.9% of samples (n = 240) from farmer stored peanuts and 98.7% of samples (n = 150) from the on-farm demonstrations were classified as safe at 4–8 weeks after harvest. Therefore, sustainable reduction of aflatoxins to safe limits is possible through greater collaboration among the value chain actors. Low-cost good agricultural practices within the remit of the growers should be prioritized alongside public awareness programmes.