Levels of infestation on three different portions of the maize cob by the weevil Sitophilus zeamais (motschulsky)

The maize weevil, Sitophilus zeamais is a major storage pest of maize that causes significant quantitative and qualitative losses to the farmer. The extent of damage caused by S. zeamais to stored maize depends on the initial level of infestation on the field before harvest. The levels ofinfestations on three different portions of maize cob were studied. Maize was planted during the minor planting season (September-December) of 2008. Maize seeds were sown on 9 plots each measuring 7.0 m x 1.5 m. Matured maize cobs were harvested 110 days after emergence. Tencobs were randomly selected from each of the plots, dehusked and cut into three portions: top, middle and bottom and stored separately in sealed plastic containers for 5 weeks. Weevils were counted weekly during the storage period. Percent damaged seeds and numbers of holes on damaged grains were counted for each portion. Percent weight loss due to S. zeamais infestation was calculated for the different maize portions. Weevil infestations were recorded on all the portions 1 week after storage. Large numbers of S. zeamais were recorded on all the portions at the endof the storage period. The middle portion recorded significantly more S. zeamais than the top and bottom portions. Percent damaged seeds; percent weight loss and mean number of holes on damaged seeds did not differ significantly

Management of Insect Pests using Chlorpyrifos Applications at Different Growth Stages of Tomato, Solanum lycopersicum L.

Field studies were conducted in Kumasi, Ghana in the major and minor planting seasons of 2013 to evaluate the effect of chlorpyrifos applications at different growth stages of tomato (Solanum lycopersicum L) for the management of insect pests. The treatments were: Chlorpyrifos at 1.5 ml / 0.5 litre of water applied (i) at the vegetative growth stage only (sprayed vegetative), (ii) at the reproductive growth stage only (starting at 50 % flowering (sprayed reproductive) and (iii) throughout the crop’s growth period (sprayed throughout). A control plot that received only water was also maintained. In both seasons, significantly (P < 0.05) less number of Bemisia tabaci Gennadius and Thrips tabaci Linderman were collected from the insecticide-treated tomato plots than the untreated, control plots, but no significant differences were observed among the treatments in the aggregations of Aphis gossypii Glover and Helicoverpa armigera (Hubner). Chlorpyrifos application in the sprayed throughout plots significantly (P < 0.05) reduced damage to tomato fruits in the major season but not in the minor season. Tomato fruits from the sprayed vegetative and sprayed reproductive plots had comparable damage as the fruits from untreated control plots. Chlorpyrifos application also significantly (P < 0.05) increased yield of tomato from the sprayed throughout plots in both seasons. The best protection to the crop against the insect pests was obtained from weekly applications of chlorpyrifos throughout the growth period of the crop (sprayed throughout plots). Key words: Tomato, Chlorpyrifos, insect pests, management, population dynamic

Build-up of insect pests and their natural enemies on rotated and non-rotated okra (Abelmoschus esculentus (L.) Moench), tomato (Lycopersicon esculentus Mill) and egg plant (Solanum melongena (L.) Moench.) fields

Objective: The quest for increased food production requires crops to be protected from pests and diseases. The readily available means of controlling pests is the application of chemical pesticides, with its attendant negative effects on humans and the environment. The study was conducted to assess the effectiveness of crop rotation as a pest control measure and how this affects the population of natural enemies of the pests.Methodology and Results: The build-up of insect pests’ of tomato, okra and eggplant and their natural enemies on rotated and non-rotated fields were studied. The rotated and non-rotated fields were each replicated 3 times. The different insect pests that infested the crops were identified and counted. Aphids and whiteflies were assessed using a scoring scale from 0 to 5. Natural enemies of the pests were also identified and counted. Significantly, larger numbers of Bemisia tabaci, Aphis gossypii, Podagrica uniforma, Zonocerus variegatus and Locusta migratoria were sampled on the crops on the non-rotated than the rotated fields. Numbers of natural enemies, Dictynia sp Coccinella sp and Camponotus sp were not significantly different on the rotated and non-rotated fields but crop yields were significantly higher on the rotated field.Conclusion and application of findings: The results of the study indicated that rotating crops on the same piece of land resulted in reduction in pests’ numbers and an increase in crop yields. The reliance on pesticides alone to manage pests may not be the best option to reduce pests because of the negative effects of pesticides on the environment. Crop rotation can therefore be adopted as a cultural control option in the overall management of pests

Evaluation of Insecticides for the Management of Insect Pests of Tomato, Solanum Lycopersicon L.

Field studies were undertaken in Kumasi, Ghana in 2012 and 2013 to evaluate the efficacy of two insecticides i.e. Lambda Super 2.5 EC (a.i- lambda cyhalothrion) and Cymethoate Super EC (a. i.-cypermethrin and cymethoate) for the management of insect pests on tomato, Solanum lycopersicum L. Lambda Super was applied at 1.5 ml/0.5 L of water whilst Cymethoate Super was applied at 0.25 ml/0.5 L of water. A control plot (water application only) was also maintained. Whiteflies, Bemisia tabaci (Gennadius), thrips, Thrips tabaci Lindeman, aphids, Aphis gossypii (Glover), leaf miners, Liriomyza sp. and the tomato fruit worm, Helicoverpa armigera (Hubner) were the most important insect pests collected on tomato in the area. In 2012, there were no significant differences among the insecticide-treated plots and the control with respect to the densities of B. tabaci, A. gossypii, Liriomyza sp. and H. armigera. Cymethoate Super treated plots recorded significantly lower number of T. tabaci than the control plots. However, in 2013, the control plots recorded significantly more aggregations of B. tabaci, H. armigera and A. gossypii than the Lambda Super and Cymethoate Super treated plots. No significant differences were obtained in the numbers of Liriomyza sp. and T. tabaci among the treatments. In 2012, the insecticide-treated plots recorded significantly higher fruit yield than the control but there were no significant differences among the treatments with respect to percent damaged fruits and mean shoot dry weight in 2013. Lambda Super and Cymethoate Super can be used to manage insect pests on tomato for increased yield. Keywords: Insecticides, efficacy, tomato pests, population densities, yiel

Occurrence of entomopathogenic nematodes (Steinernematidae, heterorhabditidae) as potential biocontrol agents against Spodoptera frugiperda infesting Zea mays

Synthetic insecticides are used worldwide to manage invasive fall armyworm (Spodoptera frugiperda) in cereals, in spite of the chemical’s prohibitive cost and threats to environmental health. In Ghana, little attention has been given to entomopathogenic nematodes as insect pest biocontrol agents, due to the existence of dismal expertise in the field. This study evaluated maize (Zea mays L.) farms for endemic entomopathogenic nematodes as potential biological control agents against fall armyworms infesting maize in Ghana. Entomopathogenic nematode juveniles were extracted using an insect baiting technique, White traps. These Rhabditid nematodes (Heterorhabditis; Steinernema) were found in 75% of 200 soil samples; and 92.5% of 40 districts targeted by this study. The Greater Accra region recorded the greatest population density (1,820 juveniles per 5 fall armyworm larvae cadavers); while; the Central region recorded the lowest density (81 juveniles per 5 fall armyworm larvae cadavers). There was high presence of entomopathogenic nematodes across the study areas. Therefore, entomopathogenic nematodes offer a promising alternative strategy for managing fall armyworm infestation of maize in Ghana to minimise over-reliance on synthetic insecticides. &nbsp

DOI: 10.5897/JSSEM12.068 ISSN 2141-2391 ©2013 Academic Journals Full Length Research Paper Nematode pests of plantain: A case study of Ashanti and Brong Ahafo regions of Ghana

A survey of plantain farms was conducted in April 2012 at four locations in two districts of Ghana. The purpose was to identify plant parasitic nematodes (PPN) associated with plantain production in Ghana. The locations were Adomakokrom and Kenyasi in the Brong Ahafo, Adanwomase and Mpobi in the Ashanti region. Demographic and sociological data of farmers, plantain root lesion scores, PPN populations per 200 cm 3 soil and 5 g plantain roots were analyzed. Nematode damage to root at Adomakokrom, Adanwomase, Mpobi and Kenyasi were 50, 75, 75 and 50%, respectively. Five nematode species were recovered from the rhizosphere of plantain. The nematodes were in the order of importance; Pratylenchus coffeae, Meloidogyne spp., Rotylenchulus reniformis, Radopholus similis and Helicotylenchus multicintus. High populations of P. coffeae (803/200 cm 3), H. multicintus (292/200 cm 3) and R. reniformis (343/200 cm 3) were extracted from soil samples at Adomakokrom, Adanwomase and Adanwomase respectively. Four parasitic nematodes; Meloidogyne spp., P. coffeae, R. reniformis and R. similis were extracted from plantain roots. Root populations were higher compared with soil samples. For sustainable plantain production in Ghana, an efficient management option must be devised. Key words: Ghana, integrated pest management, Musa spp., plant parasitic nematodes

Assessing arthropod pests and disease occurrence in cassava (Manihot esculenta Crantz) and cowpea (Vigna unguiculata L. Walp) intercropping system in the Ashanti Region, Ghana

On-station trials were conducted at CSIR-Crops Research Institute’s research farms at Kwadaso and Ejura, Ashanti Region, Ghana, during 2010/2011 cropping season, to assess the pests and disease occurrence in cassava-cowpea intercrop farming systems and their effect on yield of produce. Three improved cassava varieties and a local variety were intercropped with an improved cowpea variety, and cowpea only constituted the treatments. Abundance of Bemisia tabaci was comparable between sole cassava and cassava-cowpea intercrop, but was significantly less on the sole cowpea. The incidence and severity of cassava mosaic disease was higher on the local variety than on the improved varieties. Root yield of cassava did not differ between sole and intercropped cassava with cowpea. However, Kwadaso had higher root yield than Ejura. Dry grain yield of cowpea was similar at Kwadaso and Ejura for both sole and intercrop scenarios. This baseline information will be useful on disease and pests incidence in sole crop and cassava-cowpea intercropping system

Phenotypic and molecular evaluation of maize (Zea may L.) genotypes under field conditions in the Volta region of Ghana

Maize streak disease (MSD) is the most devastating and destructive disease of maize (Zea mays L.) in sub-Saharan Africa (SSA). Field trials were conducted in the 2014 minor and 2015 major cropping seasons to screen 16 and 17 maize genotypes, respectively, for high yield and resistance to maize streak virus (MSV) infections. The plants were scored for disease severity at 4, 6, 8 and 10 weeks after planting (WAP) based on a 1-5 visual scale (1= No infection and 5= Very severe infection). Polymerase chain reaction (PCR) test was done to detect the presence of MSV in the diseased leaf samples in order to confirm field resistance. Both phenotypic and PCR test revealed that all the maize genotypes tested in the study were infected by MSV. There was a significant varietal effect on the incidence and severity of MSD in both the major and minor seasonal trials. Genotypes ‘Abontem’,’Aburohemaa’, ‘Akposoe’, ‘Dapango’, ‘Dorke’, ‘Etubi’, ‘Honampa’, ‘Mamaba’, ‘Obatanpa’, ‘Omankwa’ and PAN 12 showed mild disease symptoms during both major and minor cropping seasons. On the other hand, genotypes ‘Dormabin’, ‘Dzinu-Eve’, ‘Enibi’, Keta 60 and PAN 53 exhibited moderate to severe symptoms during the two cropping seasons. Incidence and severity of MSD were significantly higher in the minor season than in the major season, indicating a significant seasonal effect of MSV on the maize genotypes. The yield and yield components were observed to vary significantly among the different maize genotypes and between the cropping seasons with mean yields significantly higher in the major season than in the minor season. Genotypes ‘Abontem’, ‘Aburohemaa’, ‘Akposoe’, ‘Dorke’, ‘Etubi’, ‘Honampa’, ‘Omankwa’, ‘Obatanpa’ and PAN 12 (All improved varieties), which exhibited partial resistance to MSV infection gave high seed yields during both seasons. The improved maize genotypes that were high yielding and resistant to MSV infection should be evaluated for uniform yield trials on farmers’ fields towards their release as varieties to farmers

Funding of large-scale partnerships for co-owner-ship; what works and what doesn't

Policy brief, PROIntensAfrica201

Examples of Risk Tools for Pests in Peanut (Arachis hypogaea) Developed for Five Countries Using Microsoft Excel

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 VegetalFil: Jordan, David L. North Carolina State University. Department of Crop and Soil Sciences; Estados UnidosFil: Buol, Greg S. North Carolina State University. Department of Crop and Soil Sciences; Estados UnidosFil: Brandenburg, Rick L. North Carolina State University. Department of Entomology and Plant Pathology; Estados UnidosFil: Reisig, Dominic. North Carolina State University. Department of Entomology and Plant Pathology; Estados UnidosFil: Nboyine, Jerry. Council for Scientific and Industrial Research. Savanna Agricultural Research Institute; GhanaFil: Abudulai, Mumuni. Council for Scientific and Industrial Research. Savanna Agricultural Research Institute; GhanaFil: Oteng-Frimpong, Richard.Council for Scientific and Industrial Research. Savanna Agricultural Research Institute; GhanaFil: Brandford Mochiah, Moses.Council for Scientific and Industrial Research. Crops Research Institute; GhanaFil: Asibuo, James Y. Council for Scientific and Industrial Research. Crops Research Institute; GhanaFil: Arthur, Stephen. Council for Scientific and Industrial Research. Crops Research Institute; GhanaFil: Paredes, Juan Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Fitopatología y Modelización Agrícola (UFyMA); ArgentinaFil: Paredes, Juan Andrés. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Monguillot, Joaquín Humberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Fitopatología y Modelización Agrícola (UFyMA); ArgentinaFil: Monguillot, Joaquín Humberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Rhoads, James. University of Georgia. Feed the Future Innovation Lab for Peanut; Estados Unido