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| ARPN Journal of Agricultural and Biological
Science June 2019 | Vol. 14 No.
1 |
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Title: |
The inhibitory effect of
several essential oils of medicinal plants on wilting and
soft potato rot factor in greenhouse and laboratory |
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Author (s): |
Yousef Naserzadeh, Niloufar
Mahmoudi and Mohamad Heydari |
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Abstract: |
Potato is one of the plants
that annually suffer from damages due to the soft rot and
tuber disease in storage. Nowadays, utilization of herbal
essential oils for acquisition of natural antibacterial
agents has been of great interest to control
plant-pathogens. In the present study, five medicinal herbs
of Thymus vulgaris L, Coriandrum sativum L, Cuminum cyminum
L, Rosmarinus officinalis L and Eucalyptus Globules L were
extracted using distillation with water and their inhibitory
effects on Ralstonia solanacearum bacteria (potato soft rot
factor) and Pectobacterium carotovorum bacteria (potato
wilting factor) examined through disc diffusion method. Tube
dilution method was used to determine the minimum inhibitory
concentration and minimum bactericidal concentration. The
variance analysis was carried out on tests in the form of a
completely randomized factorial design. Comparison of means
was performed based on Duncan's multiple range test (MSTAT-C
software). Thymus vulgaris L. essential oil was used in
greenhouse stage, because it showed the highest level of
inhibitory effect on both bacteria in the laboratory stage.
The obtained results showed that T. vulgaris L. essential
oil had the most antibacterial activity and effect compared
with other essential oils by creating an inhibitory shaft
diameter of 34.8 mm. For greenhouse experiments, T. vulgaris
L. essential oil was used with a concentration of 0.5% by
spray method and a concentration of 1% by pouring essential
oil into the soil. According to the results, T. vulgaris L.
reduced the occurrence of potato soft rot disease up to 41%
and potato bacterial wilt up to 44%. Therefore, T. vulgaris
L. essential oil can be utilized as an inhibitor to manage
these two diseases in potato plant due to its appropriate
antibacterial function. |
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Title: |
Assessment of resistance
status of the major storage insect pests of cocoa to
Deltamethrin in Ghana |
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Author (s): |
Azalekor W., Afun, J. V. K.,
Osekre, E. A. and Oyewo, E. A. |
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Abstract: |
Due to the versatility of
insects, many of them quickly and easily develop resistance
to insecticides they have been subjected to for long
periods. Should resistance strains arise in a population,
its control with same, and at times with similar,
insecticides becomes more difficult. Possible development of
resistance in the major insect pests of stored cocoa bean to
Deltamethrin was studied at the Entomology laboratory of the
Research Department of Quality Control Company of the Ghana
COCOBOD at Tema. Samples of Ephestia cautella, Tribolium
castaneum and Cryptolestes ferrugineus were collected from
two sites with different insecticide use history, and
exposed to different concentrations of Deltamethrin. The
results showed that the response of the two populations of
the insects followed a similar trend. Ephestia cautella was
the most susceptible insect to Deltamethrin, where 100 %
mortality was attained at 10 x 104 ppm concentration in both
populations. Generally, the 10 x 104 ppm concentration
achieved 90 % mortality in the Tribolium castaneum and
Cryptolestes ferrugineus populations studied. Therefore all
the three storage beetles tested for resistance to
deltamethrin had not developed resistance to the
insecticide. |
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