Journal of Applied Biosciences (J. Appl. Biosci.) [ISSN 1997 – 5902]
Volume 78: 6666 – 6674 Published June 30, 2014
Effect of selected essential oil plants on bacterial wilt disease development in potatoes
1Oboo H., 1Muia AW and 2Kinyua ZM
1. Egerton University Njoro, P.O Box, 536 -20115, Egerton, Kenya
2. National Agricultural Research Laboratories, P. O Box, 14733-00800, Nairobi, Kenya Corresponding author: oboohenry@gmail.com
Original submitted in on 25th March 2014. Published online at www.m.elewa.org on 30thJune 2014. http://dx.doi.org/10.4314/jab.v78i1.2
ABSTRACT
Objective: Bacterial wilt disease caused by Ralstonia solanacearum is a major constrain to production of potatoes (Solanum tuberosum). Control of bacterial wilt is very difficult as there are no effective curative chemicals. This study was aimed at investigating the potential roles of essential oil plants in control of the disease.
Methodology and Result: The plants used included: Lippie javanica (Sage brush), Ocimum suave (Cambodia) and Tarchonanthus camphorates (Camphor brush).Experiments were conducted with potatoes grown in greenhouse. Freshly harvested leaves, stems and flowers from L. javanica, O. suave and T. camphorates were chopped into small portions that were soaked in water for one hour then applied in the inoculated experimental plots. Each plot was planted with clean potato tubers and disease development observed and recorded for a period of two months. T. camphorates had significantly very low wilt incidence (P< 0.05) having reduced bacterial wilt disease incidence by more than 90%. The other two plants, O. suave and L. javanica reduced the disease by 38% and 21% respectively and were not significantly different from untreated plots.
Conclusion and Application of Results: This finding shows that essential oils are a potential source of alternative disease management against R. solanacearum. It can be concluded that essential oils plants possess antibacterial activity that is effective in control of R. solanacearum. Application of these essential oils can volatilize with increase of temperature. The application can be done by burying chopped essential oil plant parts in the soil during the time of land preparation just before planting. Further studies on the mode of action of these essential oils particularly those of T. comphrates in the control of R. solanacearum are suggested.
Key words: Essential oil plants, Potatoes, Ralstonia solanacearum, Wilt incidence
2. National Agricultural Research Laboratories, P. O Box, 14733-00800, Nairobi, Kenya Corresponding author: oboohenry@gmail.com
Original submitted in on 25th March 2014. Published online at www.m.elewa.org on 30thJune 2014. http://dx.doi.org/10.4314/jab.v78i1.2
ABSTRACT
Objective: Bacterial wilt disease caused by Ralstonia solanacearum is a major constrain to production of potatoes (Solanum tuberosum). Control of bacterial wilt is very difficult as there are no effective curative chemicals. This study was aimed at investigating the potential roles of essential oil plants in control of the disease.
Methodology and Result: The plants used included: Lippie javanica (Sage brush), Ocimum suave (Cambodia) and Tarchonanthus camphorates (Camphor brush).Experiments were conducted with potatoes grown in greenhouse. Freshly harvested leaves, stems and flowers from L. javanica, O. suave and T. camphorates were chopped into small portions that were soaked in water for one hour then applied in the inoculated experimental plots. Each plot was planted with clean potato tubers and disease development observed and recorded for a period of two months. T. camphorates had significantly very low wilt incidence (P< 0.05) having reduced bacterial wilt disease incidence by more than 90%. The other two plants, O. suave and L. javanica reduced the disease by 38% and 21% respectively and were not significantly different from untreated plots.
Conclusion and Application of Results: This finding shows that essential oils are a potential source of alternative disease management against R. solanacearum. It can be concluded that essential oils plants possess antibacterial activity that is effective in control of R. solanacearum. Application of these essential oils can volatilize with increase of temperature. The application can be done by burying chopped essential oil plant parts in the soil during the time of land preparation just before planting. Further studies on the mode of action of these essential oils particularly those of T. comphrates in the control of R. solanacearum are suggested.
Key words: Essential oil plants, Potatoes, Ralstonia solanacearum, Wilt incidence
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