4 research outputs found

    Cutting Dipping Application of Flupyradifurone against Cassava Whiteflies Bemisia tabaci and Impact on Its Parasitism in Cassava

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    The cassava whitefly Bemisia tabaci causes damage in cassava through the feeding and vectoring of plant viruses that cause cassava mosaic and cassava brown streak diseases. This study sought to explore the efficacy of cutting dipping in flupyradifurone for whitefly control and the impact of the mode of application on whitefly parasitism under farmer field conditions. The insecticide treatment significantly reduced adult whiteflies by 41%, nymphs by 64%, and cassava mosaic disease (CMD) incidence by 16% and increased root yield by 49%. The whitefly parasitism rate by Encarsia spp. parasitoids was 27.3 and 21.1%, while Eretmocerus spp. had 26.7 and 18.0% in control and flupyradifurone, respectively, and these differences were not significant. Electropenetrography recordings of whitefly feeding behaviour on flupyradifurone-treated plants showed significantly reduced probing activity and a delay in reaching the phloem as compared to the control. The findings from this study demonstrated that cassava cutting dipping in flupyradifurone significantly reduces whitefly numbers and cassava mosaic disease incidence, thus contributing to a significant root yield increase in cassava. Flupyradifurone applied through cutting dips does not significantly impact parasitism rates in cassava fields. Routine monitoring of parasitoids and predators in insecticide-treated versus control fields should be emphasized to determine the impact of pesticides on these beneficial non-target organisms. CGIAR Initiative on Plant Health and Rapid Response to Protect Food Security and Livelihoods (Plant Health Initiative)

    Efficacy of selected botanical oils against the cassava whitefly ( Bemisia tabaci ) and their effects on its feeding behaviour

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    The control of the whitefly Bemisia tabaci relies heavily on the use of synthetic insecticides. There is a need to develop alternative control strategies due to concerns about impact of these insecticides on the environmental and human health, and the threat of insecticide resistance. Botanical oil extracts could potentially be used for the management of whiteflies and other pests. The study reported here therefore aimed to evaluate the efficacy of selected botanical oils against the cassava whitefly, B. tabaci and test their effect on its feeding behaviour. Patchouli oil treatment was the most effective at repelling whiteflies in no choice and choice experiments with up to 85% of whiteflies being repelled. Oviposition was also reduced 50–89% in patchouli. Neem was found to be effective at reducing oviposition, nymph and adult emergence by 50%, 70% and 80%, respectively, in a screenhouse no choice experiment. Patchouli significantly reduced the phloem ingestion phase (E2) by 40% and potential drops (pd) by 46% compared to control plants. Neem significantly increased the non‐probing duration by 48% and reduced pd by 50% compared to the control. Patchouli and neem were found to be the most effective among the selected botanical oils. These two oils should be further evaluated for efficacy under field conditions to determine suitability for recommendation as biopesticides against the cassava B. tabaci whitefly

    Parental participation in secondary school of Zanzibar: A case of public secondary school of Zanzibar.

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    Parental involvement has been widely accepted as a way of improving learner outcomes. Studies have established that various factors influence parental involvement in school among them invitations and demands presented by school, which form a school\u27s practice. However, most of the studies have been conducted in the developed world. This study explored school practices that influence parental involvement in a secondary school in Zanzibar. The research applied a qualitative case study approach which used document analysis and interviews to collect data from 24 participants. The study found that parents participated in different ways; buying learning materials; paying school levies; disciplining the students and general guidance of the students. Participation of parents varied from one parent to the other. There are parents who are aware of the importance of their children\u27s education and are conscious of the inadequacy of resources provided by the Ministry of Education. These parents support their children\u27s learning at school and home. Nonetheless, findings revealed some parents have a negative attitude towards their children\u27s schooling. They did not support their children to further their education. This group of parents did not understand the importance of education. Additionally, findings evidenced some who understand the importance of their children\u27s education and were willingly to participate in school activities but cannot afford to pay school contribution. Thus, some parents did not pay school levies and others failed to attend school meetings. The students supported that their parents should participate in their education. Illiteracy and low incomes caused some parents not to participate. The study concluded that there should be concerted efforts to encourage a strong school-parents partnership for the school to realize educational goal

    Epidemiological Analysis of Cassava Mosaic and Brown Streak Diseases, and <i>Bemisia tabaci</i> in the Comoros Islands

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    A comprehensive assessment of cassava brown streak disease (CBSD) and cassava mosaic disease (CMD) was carried out in Comoros where cassava yield (5.7 t/ha) is significantly below the African average (8.6 t/ha) largely due to virus diseases. Observations from 66 sites across the Comoros Islands of Mwali, Ngazidja, and Ndzwani revealed that 83.3% of cassava fields had foliar symptoms of CBSD compared with 95.5% for CMD. Molecular diagnostics confirmed the presence of both cassava brown streak ipomoviruses (CBSIs) and cassava mosaic begomoviruses (CMBs). Although real-time RT-PCR only detected the presence of one CBSI species (Cassava brown streak virus, CBSV) the second species (Ugandan cassava brown streak virus, UCBSV) was identified using next-generation high-throughput sequencing. Both PCR and HTS detected the presence of East African cassava mosaic virus (EACMV). African cassava mosaic virus was not detected in any of the samples. Four whitefly species were identified from a sample of 131 specimens: Bemisia tabaci, B. afer, Aleurodicus dispersus, and Paraleyrodes bondari. Cassava B. tabaci comprised two mitotypes: SSA1-SG2 (89%) and SSA1-SG3 (11%). KASP SNP genotyping categorized 82% of cassava B. tabaci as haplogroup SSA-ESA. This knowledge will provide an important base for developing and deploying effective management strategies for cassava viruses and their vectors
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