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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.

The world’s population exceeded 7 billion in late 2011 and it is expected to reach 9.3 billion by 2050. Meanwhile, demand for food is predicted to increase between 50 and 100% by 2050. To meet the food demands of the increasing population, agricultural intensification practices including growing monocultures of high-yielding crop varieties and increased applications of fertilizers and pesticides have been used to increase productivity. These practices, however, impact negatively on biodiversity of existing flora and fauna, particularly causing huge declines in insect biodiversity. This chapter reviews present state of knowledge about agricultural intensification practices and global decline of insect biodiversity (i.e., pest and beneficial insect species) in intensive agricultural system and point out the likely drivers of these declines. It concludes the review by examining sustainable agricultural intensification practices that could be used to mitigate these biodiversity declines while maintaining productivity in intensive agricultural systems.

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 (

Suppressing pest populations below economically-damaging levels is an important element of sustainable peanut (Arachis hypogaea L.) production. Peanut farmers and their advisors often approach pest management with similar goals regardless of where they are located. Anticipating pest outbreaks using field history and monitoring pest populations are fundamental to protecting yield and financial investment. Microsoft Excel was used to develop individual risk indices for pests, a composite assessment of risk, and costs of risk mitigation practices for peanut in Argentina, Ghana, India, Malawi, and North Carolina (NC) in the United States (US). Depending on pests and resources available to manage pests, risk tools vary considerably, especially in the context of other crops that are grown in sequence with peanut, cultivars, and chemical inputs. In Argentina, India, and the US where more tools (e.g., mechanization and pesticides) are available, risk indices for a wide array of economically important pests were developed with the assumption that reducing risk to those pests likely will impact peanut yield in a positive manner. In Ghana and Malawi where fewer management tools are available, risks to yield and aflatoxin contamination are presented without risk indices for individual pests. The Microsoft Excel platform can be updated as new and additional information on effectiveness of management practices becomes apparent. Tools can be developed using this platform that are appropriate for their geography, environment, cropping systems, and pest complexes and management inputs that are available. In this article we present examples for the risk tool for each country. Instituto de Patología Vegetal Fil: Jordan, David L. North Carolina State University. Department of Crop and Soil Sciences; Estados Unidos Fil: Buol, Greg S. North Carolina State University. Department of Crop and Soil Sciences; Estados Unidos Fil: Brandenburg, Rick L. North Carolina State University. Department of Entomology and Plant Pathology; Estados Unidos Fil: Reisig, Dominic. North Carolina State University. Department of Entomology and Plant Pathology; Estados Unidos Fil: Nboyine, Jerry. Council for Scientific and Industrial Research. Savanna Agricultural Research Institute; Ghana Fil: Abudulai, Mumuni. Council for Scientific and Industrial Research. Savanna Agricultural Research Institute; Ghana Fil: Oteng-Frimpong, Richard.Council for Scientific and Industrial Research. Savanna Agricultural Research Institute; Ghana Fil: Brandford Mochiah, Moses.Council for Scientific and Industrial Research. Crops Research Institute; Ghana Fil: Asibuo, James Y. Council for Scientific and Industrial Research. Crops Research Institute; Ghana Fil: Arthur, Stephen. Council for Scientific and Industrial Research. Crops Research Institute; Ghana Fil: Paredes, Juan Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Fitopatología y Modelización Agrícola (UFyMA); Argentina Fil: Paredes, Juan Andrés. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; Argentina Fil: Monguillot, Joaquín Humberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Fitopatología y Modelización Agrícola (UFyMA); Argentina Fil: Monguillot, Joaquín Humberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; Argentina Fil: Rhoads, James. University of Georgia. Feed the Future Innovation Lab for Peanut; Estados Unidos

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.

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 of 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: Tombusviridae e), 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 less aflatoxin contamination as compared to the farmer practices. While aflatoxin levels were found to be very low (

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

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.

Production of Bird’s eye chillies (Capsicum annuum L) under tropical conditions presents a unique opportunity for small farmers to improve income. A study in 2010 and 2011 evaluated the performance of irrigated, improved Bird’s eye chilli (BEC), cvs. Demon, UHP281 70, UHP226 94, and UHP296 92, with ‘Shito Adope’, for growth, adaptability, yield, and marketability. The cultivars are categorized as being early (‘UHP281 70’ and ‘Shito Adope’), medium (‘UHP226 94’ and ‘Demon’), and late maturing (‘UHP296 92’). The UHP series had the best yield (average 12.47 Mt·ha−1). The best choice for crop performance and dried fruit quality/brightness and perceived marketability was ‘UHP281 70’ followed by ‘UHP226 94’. Economic analysis indicated that ‘UHP296 92’ had the highest total variable cost. It also had the highest marginal rate of returns (217%). It is possible to increase options for small-, medium-, and large-scale chilli pepper farmers regarding choice of superior Bird’s eye chilli peppers.

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

Insecticide protection at the vegetative, reproductive or both vegetative and reproductive (complete) crop growth stages and untreated control was used to assess yield loss due to insect pests at the different growth stages of soybean in Ghana from 2007–2009. The objectives were to determine the economic importance of the two major insect pest guilds in soybean, viz. defoliators and pod feeders, and when to apply control measures for maximum benefit. The defoliators recorded were Podagrica spp., Ootheca mutabilis (Shalberg), Zonocerus variegatus L., Sylepta derogata F., Spodoptera littoralis Boisduval, Amsacta spp. and Helicoverpa armigera Hubner. The pod feeders recorded were the pod-sucking bugs (PSBs) Riptortus dentipes F., Thyanta sp. Aspavia armigera F., Nezara viridula L. and Dysdercus volkeri Schmidt. Generally, insect densities, pod and seed damage were lower while seed yields were significantly greater and similar in plots that were protected at the reproductive stage against PSBs and those prote...

Soil arthropod pests are important constraints to peanut production in Ghana. Surveys of peanut fields were conducted from 2003–2005 to identify and estimate densities of key soil arthropod pests, and also to quantify their damage to peanut in the three regions (Northern, Upper East and Upper West) of northern Ghana. The main soil pests were termites (Isoptera: Termitidae), millipedes (Myriapoda: Odontopygidae), white grubs (Coleoptera: Scarabaeidae) and wireworms (Coleoptera: Elateridae). Across regions, termites and millipedes were the most abundant while wireworms were the least recorded. Significantly higher pest densities and pod damage by scarification and penetration were generally recorded in the Northern Region than in the Upper East and Upper West Regions. A checklist administered to farmers during the survey showed that no control practices were carried out for the pests though farmers generally were aware of the damaging effects of these pests on peanut. Field studies also were conducted at Nyankpala and Bagurugu in the Northern Region during 2005 and 2006 to determine the effects of insecticide (chlorpyrifos or carbofuran) applications to peanut at planting, pegging or at both planting and pegging on control of soil arthropod pests and on yield. Results showed that the insecticides used were similar in their efficacy against the pests. Generally, insecticide treatment lowered pest densities and pod damage resulting in increased yield over the untreated control. Yield losses in untreated plots ranged between 23 and 39%. Treatment at planting or pegging did not differ in the level of control compared with treatment at both planting and pegging. Yield was negatively correlated with pest densities and pod damage. These findings are discussed in the context of control of soil pests of peanut in Ghana.

Peanut (Arachis hypogaea L.) is the most popular legume cultivated for food and cash in the Guinea and Sudan savannah ecologies of northern Ghana. A three-year survey was conducted between 2003 and 2005 to: (1) document the prevalence of weed species, (2) determine current cropping systems and weed management practices, and (3) assess the response of peanut to weed management practices. Flora with more than 5% dominance included: (1) the dicotyledonous weeds, Corchorus olitorius L. Commelina benghalensis L., Commelina diffusa Burm., f, Desmodium scorpluras (Sw.) Desv., Hyptis suoveolens Poit., Mimosa invisa Mart., Mimosa pigra L., Mitracarpus villosus (Sw.) DC., Oldenlandia corymbosa L., Phyllanthus amarus Schum. & Thonn., Scoparia dulcis L., Tridax procumbens L., Triumfeta cordiflora A. Rich., and Vernonia galamensis (Cass.) Less.; (2) the monocotyledonous weeds Axonopus compresus (Sw.) P. Beauv., Cyperus esculentus L., Cyperus rotundus L., Digitaria horizontalisWilld., Eragrostis tremula Hochst. Ex Steud., Hackelochloa granularis (L.) O. Ktze., Kyllinga erecta Schumach. Var., Kyllinga squamulata Thonn. Ex Vahl., Paspalum scrobiculatum L., Rottboellia cochinchinensis (Lour.) Clayton, and Setaria pallide-fusca (Schum.) Stapf. & C.E. Hubbard; and (3) the parasitic weed Striga hermonthica (Del.) Benth. Land preparation practices included the use of tractors, followed by use of livestock, and lastly hand preparation. Cropping systems consisted of cereals preceding peanut, peanut preceding peanut, and intercropping peanut with sorghum (Sorghum bicolor L. Moench.), millet (Pennisetum Americanum L.), or corn (Zea mays L.). Genetically-improved peanut cultivars expressing bunch or erect growth habits were the most common cultivars although some farmers planted local cultivars expressing a distinct runner growth habit. The majority of farmers planted peanut from early June to early July based on rainfall pattern. Eighty-eight percent of peanut fields were hand weeded once, 3 to 5 weeks after planting (WAP) or twice, 2 to 3 and 5 to 6 WAP. Weed management was generally poorly timed and insufficient to prevent significant weed interference resulting in total oven-dried weed biomass ranging from 600 to 2400 kg/ha at harvest. Peanut haulm production ranged from 500 to 5500 kg/ha with improved cultivars. Pod yield production ranged from 200 to 1680 kg/ha. Results from this survey revealed the need for accelerated research and capacity building of farmers and agricultural extension agents for improved technology transfer to the peanut industry in the region.

Experiments in peanut (Arachis hypogaea L.) were conducted in northern Ghana, West Africa during 2003, 2004, and 2005 to determine interactions of cultivar, planting date, and weed management system on soil arthropod pest density, disease incidence, pod hull scarification and penetration from arthropod feeding, and pod yield. Experiments included four planting dates (28 May, 11 and 25 June, and 9 July), four cultivars (Chinese, Manipintar, JL 24, and RLRS-11), and three weed management systems (weeding four weeks, six weeks, or both four and six weeks after planting). The interaction of cultivar and planting date was significant for millipede (Peridontopyge spp.) density, penetrated pods, and pod yield. Cultivar and planting date affected density of white grubs (Schyzonicha spp.), termites (Microtermes and Odontotermes spp.), and wireworms (Elateridae); incidence of early leaf spot (Cercospora arachidicola Hori) and late leaf spot [Cercosporidium personatum (Berk. & M.A. Curtis) Deighton]; and sc...

The effects of neem (Azadirachtin indica A. Juss) on Trissolcus basalis (Wollaston), an egg parasitoid of Nezara viridula (L.), were assessed in the laboratory and in cowpea (Vigna unguiculata [L.] Walpers). Treatment of N. viridula eggs with 0.5% (225 ppm azadirachtin) aqueous solution of neem had no effect on parasitization by T. basalis, using both choice and no-choice tests. Parasitoid development and emergence from host eggs treated before or after parasitization also were not affected by neem compared with controls. Additionally, neem did not affect longevity of adult parasitoids from treated eggs or the reproductive activity of females compared with controls. In a field choice test using treated and control eggs, parasitism levels were similar. Also, parasitism of eggs was similar in treated and control cowpea plots. These results suggest that neem may be safe to parasitoids of N. viridula and could be an important component of an integrated pest management program in cowpea.

The antifeedant activity of Neemix 4.5 EC, a commercial formulation of azadirachtin from the neem tree (Azadirachta indica A. Juss), was tested against adult Nezara viridula (L.) in the laboratory using a cowpea pod-dip method. A toxicity assay was conducted by dipping fourth-instar nymphs. Feeding by adults was significantly reduced in treated pods compared with controls, based on counts of salivary deposits on pod surfaces, inside pod walls and on seeds. The antifeedant effect of azadirachtin was significantly greater on pods treated with 5% aqueous solution than on those treated with 0.5%, indicating that the antifeedant activity was related to concentration. Bugs were initially repelled by Neemix before approaching treated pods to feed. The LC50 for nymphs was 61% (27450 ppm azadirachtin) at 2 d and ranged from 1.8 to 6.2% (810 to 2790 ppm) at 5 d post-treatment, which indicated that neem was slow acting. Sublethal treatment of nymphs disrupted molting and caused morphological defects in adults. Development time to adulthood also was prolonged, and longevity of females was reduced by neem treatments. Azadirachtin may provide an effective component of a comprehensive management program for N. viridula.