Browsing by Author "Murerwa, Patrick"

Filter results by typing the first few letters
Now showing 1 - 7 of 7
  • Thumbnail Image
    Item
    Evaluation of entomopathogenic fungal isolates for management of rhopalosiphum padi and metopolophium dirhodum in wheat (triticum aestivum)
    (Egerton University, 2015-03) Murerwa, Patrick
    The success of entomopathogenic fungi as microbial control agents ultimately depends on the use of the right propagule, formulated in an optimum fashion and applied at the right time to a susceptible host. In this study, the pathogenicity of six isolates of Beauveria bassiana (Bals.) Vuill. and 14 isolates of Metarhizium anisopliae (Metsch.) Sorok to Metopolophium dirhodum (Walker) and Rhopalosiphum padi (Linneaus) was for the first time determined in the laboratory. The differential susceptibility of different developmental stages to fungal infection and the effect of different fungal formulations on aphid mortality and aphid population growth attributes was also established. Time-mortality (LT50) laboratory study results showed that three out of the twenty screened isolates, identifiable as ICIPE 84, ICIPE 51 and ICIPE 23 registered significantly (P< 0.05) shorter periods of lethal infection, indicating high level of pathogenicity or virulence of the select isolates. Further doseresponse bioassays indicated that ICIPE 51 outperformed isolates ICIPE 23 and ICIPE 84 by recording the lowest LC50 and LC90 values. Virulence for all nymphal stages was dosedependent and mortality increased with host aphids’ maturity and over time. Low doses of the isolate did not affect pre-lethal reproductive effects, such as fecundity and intrinsic rate of increase. Both aphid species were significantly (P< 0.05) more fecund in their early adulthood, suggesting the stage as ideal for biopesticide management intervention. Greenhouse and field trials established that M. anisopliae isolate ICIPE 51 has a great potential for management of R. padi and M. dirhodum, particularly when formulated in oil. However, if the entomopathogen is to be applied prophylactically, before infestation of wheat with aphids, then a sticker-based formulation would be most preferable. Additional work is required to further critically evaluate the bio-efficacy of the virulent strains in field conditions, examine methods for mass production and long term preservation as well as explore possibilities of integrating the use of the fungal isolates with other control tactics as a component of Integrated Pest Management (IPM) programmes.
  • Thumbnail Image
    Item
    Field efficacy of entomopathogens and plant extracts on Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) infesting tomato in Rwanda
    (Egerton University, 2020) Ndereyimana, Assinapol; Nyalala, Samuel; Murerwa, Patrick
    Following its outbreak in 2015, Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) immediately became one of the major threats to the food chain in Rwanda and, therefore, sustainable management options are needed to address the situation. Two field trials were established on 3rd April and 28th June 2019 to study the efficacy of entomopathogens and plant extracts on T. absoluta infestation in Rwanda. Similar procedures were followed and nine treatments were evaluated, including: entomopathogenic nematodes (EPNs) (Steinernema sp. RW14-M-C2a-3 and Steinernema sp. RW14-M-C2a-3), commercial formulations of entomopathogenic fungi (EPFs) [Metatech®WP: Metarhizium anisopliae (Metsch.) Sorok, Strain FCM Ar 23B3), Beauvitech® WP: Beauveria bassiana (Bals.) Vuill., Strain J25], plant extracts of Tephrosia vogelii and Phytolacca dodecandra, azadirachtin 0.03% EC, imidacloprid as positive control and water as negative control. The entomopathogens and azadirachtin significantly reduced leaf and leaflet damages compared to the plant extracts and the controls. However, leaf damage increased with time and reached the maximum level (100%) in 9–10 weeks after transplanting in all the treatments. In both trials, the maximum leaflet damage observed with entomopathogens and azadirachtin in 10 weeks after transplanting varied between 59.7% and 74.7% with the marketable fruit yield of 12.4–16.2 t ha􀀀 1; while leaflet damage in positive control ranged 80.0%–92.1% with marketable yield of 3.0–3.5 t ha􀀀 1. Our results suggest that the entomopathogens and azadirachtin have the potential for use in integrated pest management of T. absoluta in Rwanda, but further studies are needed to incorporate them in the IPM program
  • Thumbnail Image
    Item
    Field efficacy of entomopathogens and plant extracts on Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) infesting tomato in Rwanda
    (Egerton University, 2020-04) Ndereyimana, Assinapol; Nyalala, Samuel; Murerwa, Patrick; Gaidashova, Svetlana
    Following its outbreak in 2015, Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) immediately became one of the major threats to the food chain in Rwanda and, therefore, sustainable management options are needed to address the situation. Two field trials were established on 3rd April and 28th June 2019 to study the efficacy of entomopathogens and plant extracts on T. absoluta infestation in Rwanda. Similar procedures were followed and nine treatments were evaluated, including: entomopathogenic nematodes (EPNs) (Steinernema sp. RW14-M-C2a-3 and Steinernema sp. RW14-M-C2a-3), commercial formulations of entomopathogenic fungi (EPFs) [Metatech®WP: Metarhizium anisopliae (Metsch.) Sorok, Strain FCM Ar 23B3), Beauvitech® WP: Beauveria bassiana (Bals.) Vuill., Strain J25], plant extracts of Tephrosia vogelii and Phytolacca dodecandra, azadirachtin 0.03% EC, imidacloprid as positive control and water as negative control. The entomopathogens and azadirachtin significantly reduced leaf and leaflet damages compared to the plant extracts and the controls. However, leaf damage increased with time and reached the maximum level (100%) in 9–10 weeks after transplanting in all the treatments. In both trials, the maximum leaflet damage observed with entomopathogens and azadirachtin in 10 weeks after transplanting varied between 59.7% and 74.7% with the marketable fruit yield of 12.4–16.2 t ha􀀀 1; while leaflet damage in positive control ranged 80.0%–92.1% with marketable yield of 3.0–3.5 t ha􀀀 1. Our results suggest that the entomopathogens and azadirachtin have the potential for use in integrated pest management of T. absoluta in Rwanda, but further studies are needed to incorporate them in the IPM program.
  • Thumbnail Image
    Item
    Field efficacy of entomopathogens and plant extracts on Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) infesting tomato in Rwanda
    (Egerton University, 2020) Ndereyimana, Assinapol; Nyalala, Samuel; Murerwa, Patrick; Gaidashova, Svetlana
    Following its outbreak in 2015, Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) immediately became one of the major threats to the food chain in Rwanda and, therefore, sustainable management options are needed to address the situation. Two field trials were established on 3rd April and 28th June 2019 to study the efficacy of entomopathogens and plant extracts on T. absoluta infestation in Rwanda. Similar procedures were followed and nine treatments were evaluated, including: entomopathogenic nematodes (EPNs) (Steinernema sp. RW14-M-C2a-3 and Steinernema sp. RW14-M-C2a-3), commercial formulations of entomopathogenic fungi (EPFs) [Metatech®WP: Metarhizium anisopliae (Metsch.) Sorok, Strain FCM Ar 23B3), Beauvitech® WP: Beauveria bassiana (Bals.) Vuill., Strain J25], plant extracts of Tephrosia vogelii and Phytolacca dodecandra, azadirachtin 0.03% EC, imidacloprid as positive control and water as negative control. The entomopathogens and azadirachtin significantly reduced leaf and leaflet damages compared to the plant extracts and the controls. However, leaf damage increased with time and reached the maximum level (100%) in 9–10 weeks after transplanting in all the treatments. In both trials, the maximum leaflet damage observed with entomopathogens and azadirachtin in 10 weeks after transplanting varied between 59.7% and 74.7% with the marketable fruit yield of 12.4–16.2 t ha􀀀 1; while leaflet damage in positive control ranged 80.0%–92.1% with marketable yield of 3.0–3.5 t ha􀀀 1. Our results suggest that the entomopathogens and azadirachtin have the potential for use in integrated pest management of T. absoluta in Rwanda, but further studies are needed to incorporate them in the IPM program.
  • Thumbnail Image
    Item
    Field efficacy of entomopathogens and plant extracts on Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) infesting tomato in Rwanda
    (Egerton University, 2020) Ndereyimana, Assinapol; Nyalala, Samuel; Murerwa, Patrick; Gaidashova, Svetlana
    Following its outbreak in 2015, Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) immediately became one of the major threats to the food chain in Rwanda and, therefore, sustainable management options are needed to address the situation. Two field trials were established on 3rd April and 28th June 2019 to study the efficacy of entomopathogens and plant extracts on T. absoluta infestation in Rwanda. Similar procedures were followed and nine treatments were evaluated, including: entomopathogenic nematodes (EPNs) (Steinernema sp. RW14-M-C2a-3 and Steinernema sp. RW14-M-C2a-3), commercial formulations of entomopathogenic fungi (EPFs) [Metatech®WP: Metarhizium anisopliae (Metsch.) Sorok, Strain FCM Ar 23B3), Beauvitech® WP: Beauveria bassiana (Bals.) Vuill., Strain J25], plant extracts of Tephrosia vogelii and Phytolacca dodecandra, azadirachtin 0.03% EC, imidacloprid as positive control and water as negative control. The entomopathogens and azadirachtin significantly reduced leaf and leaflet damages compared to the plant extracts and the controls. However, leaf damage increased with time and reached the maximum level (100%) in 9–10 weeks after transplanting in all the treatments. In both trials, the maximum leaflet damage observed with entomopathogens and azadirachtin in 10 weeks after transplanting varied between 59.7% and 74.7% with the marketable fruit yield of 12.4–16.2 t ha􀀀 1; while leaflet damage in positive control ranged 80.0%–92.1% with marketable yield of 3.0–3.5 t ha􀀀 1. Our results suggest that the entomopathogens and azadirachtin have the potential for use in integrated pest management of T. absoluta in Rwanda, but further studies are needed to incorporate them in the IPM program.
  • Thumbnail Image
    Item
    Field efficacy of entomopathogens and plant extracts on Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) infesting tomato in Rwanda
    (Egerton University, 2020-04) Ndereyimana, Assinapol; l Nyalala, Samue; Murerwa, Patrick; Gaidashova, Svetlana
    major threats to the food chain in Rwanda and, therefore, sustainable management options are needed to address the situation. Two field trials were established on 3rd April and 28th June 2019 to study the efficacy of entomopathogens and plant extracts on T. absoluta infestation in Rwanda. Similar procedures were followed and nine treatments were evaluated, including: entomopathogenic nematodes (EPNs) (Steinernema sp. RW14-M-C2a-3 and Steinernema sp. RW14-M-C2a-3), commercial formulations of entomopathogenic fungi (EPFs) [Metatech®WP: Metarhizium anisopliae (Metsch.) Sorok, Strain FCM Ar 23B3), Beauvitech® WP: Beauveria bassiana (Bals.) Vuill., Strain J25], plant extracts of Tephrosia vogelii and Phytolacca dodecandra, azadirachtin 0.03% EC, imidacloprid as positive control and water as negative control. The entomopathogens and azadirachtin significantly reduced leaf and leaflet damages compared to the plant extracts and the controls. However, leaf damage increased with time and reached the maximum level (100%) in 9–10 weeks after transplanting in all the treatments. In both trials, the maximum leaflet damage observed with entomopathogens and azadirachtin in 10 weeks after transplanting varied between 59.7% and 74.7% with the marketable fruit yield of 12.4–16.2 t ha􀀀 1; while leaflet damage in positive control ranged 80.0%–92.1% with marketable yield of 3.0–3.5 t ha􀀀 1. Our results suggest that the entomopathogens and azadirachtin have the potential for use in integrated pest management of T. absoluta in Rwanda, but further studies are needed to incorporate them in the IPM program.
  • No Thumbnail Available
    Item