• Field survey and efficacy of various essential oils against chickpea pulse beetle (Callosobruchus chinensis L.) management in storage condition.

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  • 29/02/2016

This MSc thesis study was conducted by  Hari Prasad Subedi student at the Agriculture and Forestry University, Rampur, Chitwan Nepal, as part of the SAF-BIN project in Nepal in 2015.

Grain legumes are key components of cropping systems in Nepal and are important for nutrition and subsistence farming. Unfortunately they are increasingly affected by insect pests and the use of chemicals has become a common practice, without considering the harmful effects. The overall objective of this study was to test the efficacy of various essential oils in chickpea pulse beetle (Callosobruchus chinensis L.) management, as a sustainable alternative to chemical methods.The study consisted of a household (HH) survey, carried out in, Ramghat, Latikoili and Lekhgaun VDCs1 in Surkeht District, in January 2015 and a laboratory test of nine treatments against bruchids, the major pest in the studied area, undertaken at the Agriculture and Forestry University, Rampur, from March-June 2015. Fifteen HH, where food grains such as, chickpeas, lentils wheat and rice, were affected by storage pest, were purposively selected per VDC. The experiment applied a randomized design, with three replications and the efficiency of treatments (Neem oil: 3 ml/kg seeds, Clove oil: 2 ml/kg seeds, Citronella oil: 2.5 ml/kg seeds, Mentha oil: 2 ml/kg seeds, Eucalyptus oil: 3 ml/kg seeds, Bojho oil: 1 ml/kg seeds, French basil oil: 2 ml/kg seeds, Malathion: 1 mg/kg seeds, and control) was evaluated against the pulse beetle. Results of the survey reveal that storage pest infestation has increased and even occurred in cold months. Moreover, chemical pesticides were found inefficient over time. The laboratory tests show that highest mortality of adult bruchids was obtained when chickpea seeds were treated with Citronella oil followed by Malathion dust, Mentha oil and Eucalyptus oil. The number of eggs was also lowest in chickpea seeds treated with Citronella oil, followed by Mentha oil and Eucalyptus oil. Fumigant toxicity of the oils were evaluated against pulse beetle and the toxicity order was as follows: Eucalyptus oil > Citronella oil > Mentha oil > Clove oil > Bojho oil > French basil oil > Neem oil. Plant oils are sustainable alternatives for managing chickpea pulse beetle. They are effective and possess little hazardous risk against health and the environment, compared to chemicals. More plants and their products should be investigated for efficacy against plant diseases and field trials should be carried out to assess the applicability of the botanical pesticides. 

1Village development committee