Browsing by Author "Afreh-Nuamah, K."

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Abundance and distribution of the Mediterranean of the fruit fly Ceratitis capitata (Diptera:Tephritidae), in Late Valencia citrus orchards in Ghana
(International Journal of Tropical Insect Science, 2009) Afreh-Nuamah, K.; Appiah, E.F.; Obeng-Ofori, D.
The abundance and distribution of Ceratitis capitata (Wiedemann) in Late Valencia citrus orchards and other alternative host crops was investigated using trimedlure-baited traps at the University of Ghana's Agricultural Research Centre in the Eastern region of Ghana. The effect of some climatic factors on the population dynamics of the pest was also studied. The population of C. capitata increased from September to October 2006 and from February to March 2007, when Late Valencia citrus fruits were ripening or ripened. The fruit fly population was the lowest from November 2006 to January 2007 when citrus fruits were in the immature green stage. Ceratitis capitata was not trapped in mango, pawpaw and pepper fields and did not emerge from fruits of these crops. Multiple regression analyses also revealed that rainfall and temperature significantly influenced the pest population. The results of this study have important implications on the decision-making process for the safe, effective monitoring and management of C. capitata in Late Valencia citrus orchards in the study area in Ghana and probably in other areas as well.
Abundance of African invader fly, Bactrocera invadens drew, tsuruta and white (diptera: tephritidae) and influence of weather parameters on trap catches in mango in the Volta region of Ghana
(SpringerPlus, 2016-07) Adzim, C.A.; Billah, M.K.; Afreh-Nuamah, K.
The seasonal abundance of African Invader fly, Bactrocerainvadens and the influence of temperature and rainfall on fly catches was determined in two agro ecological zones; moist semi-deciduous forest area and the coastal grassland area of the Volta Region of Ghana for year of mango production. Traps containing methyl eugenol were used in monitoring the abundance of the Africa invader fly, Bactrocera invadens where data on both temperature and rainfall were collected from Meteorological Services of Ghana in Volta region. A total of 49,322 organisms captured, 45,829 were identified as Bactrocerainvadens and 3493 were non-fruit fly. There were significant differences (p < 0.05) in the number of Bactrocerainvadens captured between the agro ecological zones with relative fly densities of 5.06 F/T/D in moist semi deciduous forest area and 2.38 F/T/D in the coastal grassland zone. The result shows that climatic factors affected Bactrocerainvadens differently in different agro ecological area. There was negative correlation and highly significant (p < 0.001) correlation between fruit flies and temperature whereas there was negative correlation and high significant (p < 0.01) difference between rainfall in the moist semi deciduous forest area. In the coastal grassland area, there was negative correlation and highly significant (p < 0.001) between Bactrocerainvadens for both rainfall and temperature. Bactrocerainvadens activities peaked differently during the study period due to favourable climatic conditions. The activities of Bactrocerainvadens peaked during weeks 7 and 29 in the moist semi deciduous forest area while their activities peaked during weeks 3 and 24 for the coastal grassland areas. Both agro ecological zones recorded the presence of Bactrocerainvadens, their number and proportion varied considerably with associated effects of the weather parameters on their abundance. The effect of weather parameters on the abundance of bactrocera invadens requires the development of degree day models to manage them. © 2016, The Author(s).
African weaver ant-produced semiochemicals impact on foraging behaviour and parasitism by the Opiine parasitoid, Fopius arisanus on Bactrocera invadens (Diptera: Tephritidae)
(Biological Control, 2014-12) Appiah, E.F.; Ekesi, S.; Afreh-Nuamah, K.; Obeng-Ofori, D.; Mohamed, S.A.
The fruit fly, Bactrocera invadens is an alien invasive pest of mango in Africa. The predatory African weaver ant, Oecophylla longinoda is being promoted for managing B. invadens and classical biological control with the Opiine parasitoid, Fopius arisanus is also underway. The current study investigated interactions between these two natural enemies. Specifically we assessed whether semiochemicals deposited by the ant on leaves and fruit affected the landing behavior of F. arisanus, its patch residence time and subsequent parasitism rates. Results showed that significantly more F. arisanus landed on 'ant-unexposed' leaves and fruits (leaves: 3.8 ± 0.5-7.7 ± 0.8; fruits: 4.1 ± 0.1-8.1 ± 1.2) compared with 'ant-exposed' leaves and fruits (leaves: 0.4 ± 0.1-2.5 ± 0.3; fruits: 0.2 ± 0.1-2.8 ± 0.7) from mango, citrus, guava and avocado. Parasitoid patch residence times were significantly longer on 'ant-unexposed' mango fruits (654.2 ± 28.4. s-1034.2 ± 112.6. s) compared to 'ant-exposed' fruits (75.2 ± 18.4. s-144.8 ± 42. s) regardless of whether eggs of B. invadens were present. In terms of percent parasitism, F. arisanus achieved significantly higher parasitism rates in B. invadens from 'ant-unexposed' mango fruits (72.8 ± 3.8) compared with 'ant-exposed' fruits (18.2 ± 1.8). Regression analysis showed a significant inverse relationship between the duration of exposure of mango fruits to ant-produced semiochemicals and the number of F. arisanus adults landing on fruits and percent parasitism. In field cages, 32% parasitism of B. invadens was achieved in mango fruits on trees without ants and 11% in mango fruits on ant-infested trees. These results suggest the potential for biotic interference between the two natural enemies if they are recommended for use within the same ecosystem. © 2014 Elsevier Inc.
Arthropod pests of plantain/banana. In: Obeng-Ofori, D. (ed.}, Major Pests of Food and Selected Fruit and industrial Crops in West Africa. - Accra, Ghana
(City Publishers, pp. 77-80, 2008) Afreh-Nuamah, K.
Assessment of impacts of fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae) on maize production in Ghana
(Oxford University Press, 2021) Koff, D.; Kyerematen, R.; Eziah, V.Y.; Osei-Mensah, Y.O.; Afreh-Nuamah, K.; Aboagye, E.; Osae, M.; Meagher, R.L.
Spodoptera frugiperda was considered an insect pest only in the Americas until its first report in African countries in 2016. In this study, farmers and agricultural officials in Ghana were interviewed on their perceptions and knowledge of the pest, on infestation and maize yield variations across years, and on management practices. Farms were inspected to determine the infestation level of 100 plants per hectare. Interviews revealed that farmers were familiar with the larval stages of this pest and noticed that the pest occurred throughout the year, but populations of S. frugiperda increased only during cropping seasons. Infestation levels reported by farmers in surveys were much lower in 2018 (30.38%) than in 2017 (80.92%). Farm inspections confirmed that infestation levels were much lower in 2018 (20.90%) than 2017 (73.70%). The belt formed by Guinea Savannah, Transitional Zone, and Semi Deciduous Forest Agro-Ecological Zones (AEZs) recorded the highest infestations while the lowest were observed from the Sudan Savannah and Tropical Rain Forest AEZs. Insecticides were the most commonly used tactic to manage populations of this new pest. Maize yields increased across Ghana between 2013 and 2015 from 1.52 to 1.73 t/ha, decreased between 2015 and 2017 to 1.55 t/ha, and increased to 1.69 t/ha in 2018. The impact of fall armyworm injury to maize production is discussed.
Assessment of storability of two maize cultivars in a hermetic triple layer biodegradable bag
(Acta Horticulturae, 2015-02) Ansah, F.A.; Fatunbi, A.O.; Adekunle, A.A.; Obeng-Ofori, D.; Afreh-Nuamah, K.; Anankware, J.P.; Badu, A.S.
Storage of maize is very important for food security, especially in developing countries; like Ghana. However, several abiotic and biotic factors cause considerable losses during its storage. Therefore, the work studied the effectiveness of hermetic triple layer biodegradable bags (HTLBB) and polypropylene interwoven bags (PIB) in reducing losses of stored maize. Experiments were conducted in a small holder farmer storage crib and in a laboratory. A factorial combination of HTLBB, PIB and maize cultivars, improved 'Obatanpa' and local 'Denkye' were used. The samples were stored for six months at an average temperature of 27°C and 58% RH. The moisture content, hidden infestation, weight loss, germination capacity and colour were assessed. A significant increase in the moisture content of both cultivars (12.4-15.4%) was found in HTLBB-stored samples probable due to airtight conditions and the respiratory activities of grains, while in PIB no significant differences were found (12.4-12.9%). Laboratory and field assessment of percentage germination and emergence was higher in 'Obatanpa' than in 'Denkye'. However, HTLBB-stored samples, kept 90% of germination capacity while in PIB-stored, a maximum of 60%. Weight losses were also lower in HTLBB-stored 'Obatanpa' and 'Denkye' at 7.4 and 3.8% than PIB-stored at 15.1 and 9% respectively, attributable to varietal type and hidden infestation. Colour changes were observed in both storage bags which were related to possible increase in carotenoid content during storage. As main conclusion, HTLBB has the potential to protect stored maize better than PIB without any chemical treatment; provided its moisture content is very low.
Bioactivities of Six Indigenous Ghanaian Plants in Managing Sitophilus Zeamais and Prostephanus Truncatus in Stored Maize in Volta Region
(University of Ghana, 2014-07) Ankutse, D.K.; Eziah, V.Y; Afreh-Nuamah, K.; University of Ghana, College of Basic and Applied Sciences , School of Agriculture , Department of Crop Science
The increasing rate of pest resistance, high cost and health risk in the use of insecticides have become an issue of Public concern. This research therefore was undertaken to identify and assess botanicals that are used by the farmers of Volta Region to manage S. zeamais and P. truncatus in stored maize grains. A survey conducted revealed A. indica, C. anisata, P. amarus, P. nitida, V. amygdalima , N. latifolia and M. charantia as grain protectants against stored insect pests. All the above mentioned botanicals were used for the experiment except A. indica since its potential against grain storage pest has long been established. Dried powders at (5 and 10%) and aqueous extracts (0.1 and 0.2 g/mL) of botanicals were prepared and evaluated for their insecticidal activity against P. truncatus and S. zeamais. The potency of botanicals varied with plant species and dose rate. Maximum toxicity of plant powders and methanol extracts to insects were observed in V. amygdalima treatment. At higher concentration of 0.2 g/mL, toxicity of V. amygdalina was 83.3 and 86.7% to P truncatus and S. zeamais respectively. All plant extracts at 0.2 g/mL showed significant (P<0.05) difference in repellency to Actellic; however, C. anisata expressed the highest repellent activity to P. truncatus and S. zeamais at 80.0 and 66.7% respectively. There was reduction in oviposition and emergence of eggs when grains were treated with extracts of botanicals compared to the control. There was reduction in the number of adult insects when immature stages of insects were treated with methanol extracts of botanicals. These results suggest that the botanicals tested have the potential in the development of post-harvest protection technology against, P. truncatus and S. zeamais as the major pest of stored grains. It is therefore recommended to be used by farmers to control P. truncatus and S. zeamais in stored maize grains.
Comparative susceptibility of Adult Africa Invader fly, Bactrocera invadens (Diptera: Tephritidae) to some selected insecticides
(Journal of Agricultural Science, 2012) Abdullahi, G.; Sule, H.; Obeng-Ofori, D.; Afreh-Nuamah, K.; Billah, M.K.
With the recent introduction of B. invadens in Africa and its devastating role in crop production, especially mango, with currently no registered insecticides for use against this fly in Ghana, the susceptibility of the fly to four commercially available insecticidal products namely, Cydim Super, Pyrinex 48 EC, Diazol 50 EW and Deltapaz was evaluated in the laboratory. The bioassay was conducted using three (3) different doses of each insecticidal product, by dipping 4x4 cm hardboard panels into the respective doses. Susceptibility of the flies to insecticides were assessed on freshly treated panels, 3-day-old and 6-day-old treated panels in some ventilated transparent bottles of 1 litre capacity. Adult flies aged between 4-12 days were used for the bioassays. The bioassay results indicated that the adult flies were more susceptible to Diazol (Diazinon) (LC50 = 0.6 ml/L; LC90 = 1.3 ml/L) and Pyrinex (Chlorpyrifos) (LC50 = 0.8 ml/L; LC90 =1.0 ml/L), and hence gave the least LT50 and LT90 times. Least susceptibility was recorded with Deltapaz (Deltamethrin) (LC50 = 3.1 ml/L; LC90 = 5.2 ml/L). It could be concluded that the control of B. invadens can be achieved more effectively by the use Pyrinex (Chlorpyrifos) and Diazol (Diazinon). The use of Pyrinex appears to be more economical to the resource poor farmers as it had least LC90 of 1.0 ml/L compared to 1.3 ml/L for Diazol in 30 min.
Differential effects of weather, plant phenology and predators on the seasonal variation of aphids on cabbage
(Journal of Applied Entomology, 2023) Forchibe, E.E.; Fening, K.O.; Narh-Madey, B.; Afreh-Nuamah, K.; Cobblah, M.A.; Wamonje, F.O.; Carr, J.P.
The aphids Lipaphis erysimi pseudobrassicae (Davis) and Myzus persicae (Sulzer) pose serious threats to the production of cruciferous crops in the tropics. Understanding their population dynamics is important for developing integrated pest management programmes to minimize their damage to crops. This study investigated the effects of climatic factors, natural enemies and plant age on the population dynamics of these pests. The population density of aphids and their natural enemies in 20 cabbage plants, and weather conditions were monitored for five cropping seasons from 2019 to 2021 in two agroecological zones of Ghana (Coastal Savannah and Deciduous Forest zones). The highest population density of L. e pseudobrassicae was recorded in January (dry season) in both agroecological zones, while the highest population density for M. persicae occurred in September (minor rainy season) and August (dry spell) in the Coastal Savannah and Deciduous Forest zones, respectively. The highest aphid densities were noted to occur during periods with low relative humidity and low rain fall. The population density of L. e. pseudobrassicae was significantly negatively related to plant age, air temperature and relative humidity, and positively related to syrphids (Paragus borbonicus) and spiders in the Coastal Savannah zone, while in the Deciduous Forest zone, it was significantly positively related to coccinellids. On the other hand, M. persicae population density was significantly positively related to syrphids and coccinellids in the Deciduous Forest zone. Rainfall negatively affected syrphids in the Coastal Savannah zone, while air temperature positively affected syrphids and negatively affected spiders in the Deciduous Forest zone. Coccinellids had a significant positive relationship with relative humidity in the Deciduous Forest zone. This study provides important insights into the key factors that regulate aphid population densities on cabbage and will support development of timely interventions to manage these pests.
The effect of fruit fly larval density on some quality parameters of mango
(Journal of Animal & Plant Sciences, 2011) Akoto, S.H.; Billah, M.K.; Afreh-Nuamah, K.; Owusu, E.O.
Three varieties of mango, Jaffna, Palmer and Kent were infested with different first instar larval densities (10, 20 and 30) of the invasive fruit fly species, Bactrocera invadens Drew, Tsuruta & White. This was to determine the effect of each of the densities on three fruit quality parameters. The parameters included Total Soluble Solids (TSS), Percentage Titratable Acidity (% T.A.) and pH, of which TSS and pH showed decreasing trends while % T.A. showed an increasing trend with time. In the controlled treatments where fruits were either held intact or punctured but with no introduction of larvae, there was an increase in pH and TSS and a decrease in %T.A.. The shelf-life, which was taken as the period from the first day of treatment till signs of damage were observed, saw the three varieties infested with 10 larvae lasting up to 6 days, while fruits infested with 20 and 30 larvae lasted for 3 days. The shelf life of the controlled treatments for all the varieties lasted till the 15th day. The presence of fruit fly larvae in fruits causes a number of changes in internal quality parameters such as the TSS, pH, % T.A. and the internal damage area. While pH and TSS decreased with storage time, % T.A. increased with storage time compared with the controlled fruits. Total damage area of fruits was also increased with increase number of larvae introduced. pH, TSS and % T.A. of Jaffna and Kent on the 3rd day of storage were almost the same as their control treatments. Despite the differences, the presence of fruit fly larvae in fruits (irrespective of number), will have negative impact on the internal quality parameters after the 3rd day of storage and reduce the market (export and locally) value of the fruits.
The effect of fruit fly larval density on some quality parameters of mango
(2011) Akoto, S.H.; Billah, M.K.; Afreh-Nuamah, K.; Owusu, E.O.
Three varieties of mango, Jaffna, Palmer and Kent were infested with different first instar larval densities (10, 20 and 30) of the invasive fruit fly species, Bactrocera invadens Drew, Tsuruta & White. This was to determine the effect of each of the densities on three fruit quality parameters. The parameters included Total Soluble Solids (TSS), Percentage Titratable Acidity (% T.A.) and pH, of which TSS and pH showed decreasing trends while % T.A. showed an increasing trend with time. In the controlled treatments where fruits were either held intact or punctured but with no introduction of larvae, there was an increase in pH and TSS and a decrease in %T.A.. The shelf-life, which was taken as the period from the first day of treatment till signs of damage were observed, saw the three varieties infested with 10 larvae lasting up to 6 days, while fruits infested with 20 and 30 larvae lasted for 3 days. The shelf life of the controlled treatments for all the varieties lasted till the 15th day. The presence of fruit fly larvae in fruits causes a number of changes in internal quality parameters such as the TSS, pH, % T.A. and the internal damage area. While pH and TSS decreased with storage time, % T.A. increased with storage time compared with the controlled fruits. Total damage area of fruits was also increased with increased number of larvae introduced. PH, TSS and % T.A. of Jaffna and Kent on the 3rd day of storage were almost the same as their control treatments. Despite the differences, the presence of fruit fly larvae in fruits (irrespective of number), will have negative impact on the internal quality parameters after the 3rd day of storage and reduce the market (export and locally) value of the fruits
Effect of some climatic factors on insects associated with citrus agro-ecosystems in Ghana
(Journal of Biodiversity and Env. Science (JBES) Vol. 5, No. 4, p 428-436, 2014) Aidoo, O.F.; Kyerematen, R.; Akotsen-Mensah, C.; Afreh-Nuamah, K.
The present study investigates the effects of some climatic factors on insects associated with citrus orchards in two different agro-ecological zones in Ghana. The study showed that, climatic factors affected insects differently in different agro-ecological zones. There was a negative and highly significant (P˂0.01) correlation between insect abundance and rainfall in the Coastal Savannah zone whereas the correlation between mean temperature and insect abundance was negative and significant (P˂0.05) in the Semi-Deciduous Rain Forest zone. Numbers of insect species peaked differently in some months during the study period due to favourable climatic conditions for their reproduction, growth and activities. The month of February was most favourable for the insects in the Semi-Deciduous Rain Forest zone whiles January was most favourable for the Coastal Savannah zone. Similarly, some months were more favourable for pests of citrus in Ghana; January and February for Ceratitis ditissima and Leptoglossus sp. in both agro-ecological zones and, January and February for Achaea sp. in the Semi-Deciduous Rain Forest and Coastal Savannah respectively. The months of October and September were most favourable for Zonocerus variegatus in the Coastal Savannah zone and Semi-deciduous rain forest zone respectively during the study period. Even though the two different agro-ecological zones had common pests, the proportions and peak periods however varied. The differences are crucial with regards to developing integrated pests management strategies to control insect pests of citrus in Ghana.
Effect of some traditional plant components on the control of termites, Macrotermes, spp,
(African Journal ofScience and Technology 2(9): 1-8, 2008) Afreh-Nuamah, K.; Owusu, S.O.; Akutse, K.S.
Effect of temperature on immature development and longevity of two introduced opiine parasitoids on Bactrocera invadens
(Journal of Applied Entomology, 2013-09) Appiah, E.F.; Ekesi, S.; Salifu, D.; Afreh-Nuamah, K.; Obeng-Ofori, D.; Khamis, F.; Mohamed, S.A.
Temperature-dependent development, parasitism and longevity of the braconid parasitoids, Fopius arisanus Sonan and Diachasmimorpha longicaudata Ashmed on Bactorcera invadens Drew Tsuruta & White, was evaluated across five constant temperatures (15, 20, 25, 30 and 35°C). Developmental rate decreased linearly with increasing temperature for both the parasitoid species. Linear and Brière-2 nonlinear models were used to determine the lower temperature threshold at which the developmental rate (1/D) approached zero. For F. arisanus, lower thresholds to complete development estimated with the linear and nonlinear models were 10.1 and 6.9°C, respectively. The total degree-days (DD) required to complete the development estimated by the linear model for F. arisanus was 360. In D. longicaudata, the linear and nonlinear models estimated lower thresholds of 10.4 and 7.3°C, respectively, and the total DD estimated was 282. In F. arisanus, percentage parasitism differed significantly across all temperatures tested and was highest at 25°C (71.1 ± 2.5) and lowest at 15°C (46.4 ± 1.4). Parasitoid progeny sex ratio was female biased at all temperatures except at 20°C. In D. longicaudata, percentage parasitism was highest at 20°C (52.2 ± 4.0) and lowest at 15°C (27.7 ± 2.5). Parasitoid progeny sex ratio was female biased and similar for all temperatures. Adult longevity of both parasitoids was shortest at 35°C and longest at 15°C, and females lived significantly longer than males at all temperatures tested. Our findings provide some guidance for future mass rearing and field releases of the two parasitoids for the management of B. invadens in Africa. © 2013 Blackwell Verlag, GmbH.
Effectiveness of Triple-Layer Hermetic Bags against Aflatoxins in Stored Maize
(University of Ghana, 2015-07) Fusseini, I.; Afreh-Nuamah, K.; Torkpo, S.; University of Ghana, College of Basic and Applied Sciences, School of Agriculture, Department of Crop Science
Aflatoxin contamination of agricultural commodities is gaining public prominence in Africa where it is pervasive due to favourable environmental conditions and high consumption of maize. Aflatoxins are toxic secondary fungal metabolites that contaminate dietary staples such as maize and groundnut resulting in adverse effect on food security, health and trade. This study evaluated the effectiveness of triple-layer hermetic bag to control aflatoxin in stored maize. A factorial experiment was conducted involving 2.5 kg of Obatanpa maize variety at moisture content between 12%-13%. Two storage bags (triple-layer hermetic bag and polypropylene interwoven bag) and two insect pests (Sitophillus zeamais and Prostephanus truncatus) were used in the study. Oxygen depletion and carbon dioxide elevation, temperature, relative humidity and dew point in the different storage bags and the storage environment were measured during the six months storage period. Different levels of temperature (16 oC, 30 oC and 38 oC) were also monitored to ascertain their effect on the performance of the triple-layer bag against aflatoxins in stored maize. The study showed that most farmers introduced to the hermetic technology by NGOs adopted and used it to preserve various agricultural commodities from insect pests. The vulnerability of the high-density polyethylene (HDP) bags to leakages and tearing and the cost of replacing a torn HDP bag were predominant concerns expressed by farmers during the survey in the Techiman Municipality. Field studies revealed that extreme fluctuation in temperature in the field negated the effectiveness of the air-tight condition created in the triple-layer hermetic bag to control aflatoxigenic fungi. There was significant difference (p<0.05) in moisture content of maize grains in the different storage bags with respect to insect infestation and changes in season from dry to rainy season in the storage crib. The mean aflatoxin level of maize infested with insect pests in the conventional bag was significantly higher (p<0.05) than insect-infested grains in the triple-layer hermetic bag. The triple-layer hermetic bag preserved the germination capacity of the seed maize much longer than polypropylene interwoven bag. There were significant differences (p<0.05) in the concentration of aflatoxin at the different temperature levels in the different storage bag technologies. The polypropylene bag had aflatoxin level (38.8 μg/kg) near the initial aflatoxin content of 38.2 μg/kg after three months of storing at a constant warm temperature (38 oC). The result of the research showed that, irrespective of the type of storage bag used for storing maize, the most critical factor to control aflatoxin is storing grains at save moisture content (<11%) and keeping them in storage structures that ensure environmental conditions that are relatively stable.
Effects of Banana Weevil and Nematode Infestation on the Growth and Yield of Plantain (Mus4.Aab ) in Ghana
(University of Ghana, 1997-12) Udzu, A.; Afreh-Nuamah, K.; Green, K. R.; University of Ghana, College of Basic and Applied Sciences, School of Biological Sciences, Department of Animal Biology and Conservation Science (DABCS)
Banana weevil (Cosmopolites sordidus Germar) and nematodes (particularly Pratylenchus coffeae [Zimmerman] Filipjev, Schuurmans and Stekhoven), are well known pests of plantain world-wide. An investigation was therefore conducted to quantify yield loss due to the individual and combined infestation of these pests on plantain in Ghana. From the studies on the effects of these pests on plantain using a natural nematode infestation and artificial and natural weevil population, it was concluded that weevil damage to plantain corms caused by the feeding and tunneling activity of the larvae had serious effect on the vitality of the plants. High densities of Pratylenchus coffeae associated with severe necrosis of the roots at flowering and harvest was the cause of a drastic deterioration of both primary and secondary roots. Results however, indicated that, with the occurrence of these two pests a much greater destruction of the corms, primary and secondary roots of the plants was readily expected. Weevil effect thus accounts for the high plant breakage after flowering, failure to reach maturity and a 34.8 % yield reduction. Nematodes effect on the other hand resulted in a complete failure of the majority of plants to flower, a total reduction in the productivity of the mat and a consequent yield loss of 63.7%.. Massive death was the immediate result when the interaction of these pests was pronounced at the early growth stage of the plants, whereas, failure to flower and the inability to reach bunch producing stage was the effect when infestation was delayed. The ultimate effect of this interaction was the drastic reduction in yield of about 85%. On the basis of the present study, the economic importance of these pests whether in combination or occurring separately on plantains in Ghana, cannot be overemphasized
Effects of different pesticide management options on the population dynamics of aphids, Lipaphis erysimi pseudobrassicae (Davis) and Myzus persicae (Sulzer) (Hemiptera: Aphididae), their natural enemies and the yield of cabbage
(Science and Development, 2017) Forchibe, E.E.; Fening, K.O.; Afreh-Nuamah, K.
Cabbage is a popular vegetable grown in Ghana and it serves as an important source of livelihood for smallscale farmers. Aphids are major pests of cabbage in the field and as such, farmers have resorted to the indiscriminate use of insecticides which have had adverse environmental and health implications. The current study sought to investigate the effect of commonly used management options on the population of aphids, Lipaphis erysimi pseudobrassicae (Davis) and Myzus persicae (Sulzer) (Hemiptera: Aphididae), their natural enemies and the yield of cabbage. Cabbage seedlings were planted during the major and minor seasons of 2015 in 3 x 3 m plots and the treatments used included Chlorpyrifos, Lambda-cyhalothrin, hot pepper, Capsicum futescens fruit extract, neem, Azadirachta indica seed extract, solution of local soap (alata samina) with water as a control. Ten cabbage leaves per treated plot were randomly sampled weekly into 70% alcohol to obtain actual counts of aphids and their natural enemies. The least number of aphids was recorded in the neem treated plots, while Lambda-cyhalothrin treated plots recorded the highest number of aphids. The control and biopesticide treated plots recorded the highest numbers of the natural enemies (hoverflies, ladybirds and spiders). The highest yield and marketability was recorded in the neem treated plots for both seasons. The yield and marketability of cabbages obtained from plots sprayed with alata samina and pepper was also higher than that obtained from the control, Lambdacyhalothrin and Chlorpyrifos treated plots, with the insecticide treated plots recording the least number of marketable heads. It offered the most promising solution. The current findings suggest that the crude neem seed extract, and to some extent local soap, alata samina, and pepper, are effective and safe options for managing aphids on cabbage.
Efficacy of the Multiple-Layer Hermetic Storage Bag for Biorational Management Of primary Beetle Pests of Stored Maize
(IDOSI Publications, 2012) Anankware, P.J.; Fatunbi, A.O.; Afreh-Nuamah, K.; Obeng-Ofori, D.; Ansah, A.F.
This paper reviews the destructive effects of Prostephanus truncatus and Sitophilus zeamais on maize grain and the effectiveness of the triple-layer hermetic bag storage system as a control measure. Maize (Zea mays L.) is the most important cereal in Ghana and is the staple food for over 90% of the population. The availability and safety of this important food crop is threatened by insect pests, rodents and fungal attacks due to inappropriate storage methods. Infestation by insect pests accounts for between 20 to 50% of post-harvest losses in maize. Pesticides and other artificial gaseous techniques are no longer acceptable due to food quality and environmental related issues. In the light of the foregoing, the hermetic storage techniques have recently been revisited as a way to control insect pest and other microbial attack in maize grain. The system creates an air tight environment to rapidly exterminate insect development and suppress micro flora activity. A recent development is the invention of the triple layer hermetic bag using biodegradable plastic materials. This is being investigated to determine its efficiency as a storage technique that prevents insect attack and yields product with good food quality and market acceptability. Quantitative figures are needed about the current distribution and losses caused by insect pests especially P. truncatus and S. zeamais. There is also the need to fill the knowledge gaps and provide adequate information needed to inform decisions for the use of the use of hermetic storage technology and its further refinement.
The efficacy of two bio-rational pesticides on insect pests complex of two varieties of white cabbage (Brassica oleracea var. capitata L.) in the coastal savanna region of Ghana
(springer, 2021) Ngosong, N. T.; Boamah, E. D.; Fening, K. O.; Kotey, D.A.; Afreh-Nuamah, K.
Abstract Insect population count and yield were used to determine the effectiveness of two bio-rational pesti cides -a commercial formulation of Pieris rapae granu losis virus and Bacillus thuriengensis, Bypel 1® (PrGV + Bt) (1.5 g/l w/v) and aqueous neem kernel extract (ANKE) (50 g/l w/v), on the insect pests complex of two cabbage varieties, KK cross and Oxylus for two consecutive cropping seasons of 2016/2017. The exper iment was laid in a split-plot design with three replica tions, with the cabbage varieties as main plots and the bio-rational pesticides as subplots. Cabbage plots treat ed with Bypel 1® and ANKE had the lowest population of Plutella xylostella, Brevicoryne brassicae, Hellula undalis, Bemisia tabaci and Thrips tabaci for both sea sons. The control plot consistently had higher pest population in both seasons. There was no detrimental effect of bio-rational pesticides on natural enemies. The bio rational pesticides-treated plots produced higher yield than control plots. Mean numbers of P. xylostella was higher on KK (0.61, 1.46) compared to Oxylus (0.65, 1.70) in both seasons, respectively. The yield between the cabbage varieties was not significantly different in both seasons, although Bypel 1® and ANKE treated plots generally produced significantly higher yields than the control plot. Yield between both cropping seasons was significantly different (p = 0.039). These findings provide evidence that bio-rational pesticides may offer effective management of the pest complex of cabbage and may be successfully used as an integral part of IPM in Africa as a means to curb the abuse of synthetic insecticides.
Evaluation of Neem (Azadirachta Indica A. Juss) Seed Extracts For the Management of Some Cocoa Mirid Species
(University of Ghana, 1997-10) Adu-Acheampong, R.; Afreh-Nuamah, K.; Owusu-Manu, E.; Coker, W.Z.; University of Ghana, College of Basic and Applied Sciences, School of Agriculture, Department of Crop Science
Laboratory and field studies were conducted to investigate the toxicity, antifeedant activity, moulting inhibition property and persistence of two neem seed extracts against the cocoa mirids Distantiella theobroma (Dist.) and Sahlbergella singularis Hagl. The study also investigated the effects of neem extracts on nontarget arthropods. Propoxur (Unden 200 EC) was used for baseline comparison. In the laboratory bioassays, the neem was applied at the concentrations of 5%, 10%, 15%, 20%, 25%, and 30% weight/volume (w/v) (water extract) and 0.77%, 1.54%, 3.08%, and 4.62% (neem oil). The neem extracts acted mainly as antifeedants and stomach poisons against the mirids. The 20% neem extract provided the greatest antifeedant effect (84.3%) and gave the highest nymphal mortality (93.3%) 30 hours after treatment. Moulting was significantly inhibited (>50% inhibition) by the neem oil. LC50 values estimated from regression equations were 8.17% and 2.67% for the water extract and neem oil, respectively. LT50 values for the 20% neem seed water extract and 4.62% neem oil were 16 and 24 hours respectively. LC50 for propoxur is 2.73 x 10'3 % (Marchart, 1971). In subsequent experiments, the 20% neem seed extract and 0.3% and 3.0% neem oil were tested in the field. Two application methods, spraying a tree from one side of the trunk into the canopy (T1 method), or spraying from both sides of the tree (T2 method), were compared using the "Urgent" GmbH motorised knapsack mistblower at the 2nd and 3rd nozzle restrictor positions. When the mistblower was operating at the 2nd restrictor position, the resulting application rates were 75 and 480 litres/ha for the T1 and T2 methods, respectively. Corresponding application rates at the 3rd restrictor position for T1 and T2 methods were 100 and 640 litres/ha. Results from the field study confirmed the short residual activity of neem observed in the laboratory. Reduction in mirid numbers after 48 hours of treatment at the 2nd restrictor position were 80.3%, 51.7% and 80.4% for the 20% neem seed water extract and 0.3% and 3.0% oil treatments, respectively using the restrictor 2. Restrictor 3 gave 88.9% reduction in mirid numbers after 48 hours of treatment. No significant difference in reduction in mirid numbers was found between the two different restrictor settings (P = 0.05) within 48 hours. When trees were sprayed from two sides, a relatively better result was obtained than when they were sprayed from one side only. The addition of 4.5 ml propoxur per litre of neem extract increased efficacy significantly. The T2 method gave a more prolonged control of the mirids as the population did not recover even after two weeks of treatment. The more enhanced spray coverage achieved using the T2 method was therefore promising. Current trend of pesticide application technology however, is towards low volumes of application. For this reason, application of neem and propoxur mixture, using the T1 method (75 liters per ha.) may offer a more practical approach of mirid pest management especially in small scale farming systems. Neem was observed to be toxic to some nontarget insects, particularly ants, and spiders. Further investigation into neem/propoxur combinations and hazardous effects on nontarget species is suggested.