H. Zeinali; H. Hosseini; M.H. Shirzadi
Abstract
Mint (Mentha piperita L.), belonging to Labiatae family, is one of the most important plants, which is used widely in terms of pharmaceutical, food and health. Essential oils and compounds are important components of the plant and are severely affected by agricultural agents. In this study, the effects ...
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Mint (Mentha piperita L.), belonging to Labiatae family, is one of the most important plants, which is used widely in terms of pharmaceutical, food and health. Essential oils and compounds are important components of the plant and are severely affected by agricultural agents. In this study, the effects of nitrogen fertilizer and harvesting time on yield and yield components, essential oil and menthol were studied. A split-plot design with three replications was used. The measured traits included leaf length, leaf width, plant height, fresh weight per square meter in the first and second harvest, fresh weight of 100 leaves, essential and oil menthol of the first second harvest, shoot yield and essential oil yield per hectare. Variance analysis results showed that different levels of nitrogen and harvesting time had a significant effect on all traits except for leaf length. The interaction of nitrogen and harvesting time showed a significant difference for all traits except leaf length and width. Mean comparison of traits showed that the plant height, fresh weight per square meter, fresh weight of 100 leaves, essential oil of the first harvest, menthol of the first and second harvest, shoot yield per hectare and essential oil yield increased with increasing of nitrogen intake. Mean comparison of different harvesting times showed that the highest shoot yield and essential oil yield were obtained at budding stage. The interaction between different levels of nitrogen fertilizer and harvesting time also showed that the highest shoot yield per hectare was obtained by the application of 200 kilograms of nitrogen fertilizer per hectare at budding stage. The highest amount of menthol was obtained at consumption level of 300 kg nitrogen fertilizer per hectare and at 50 % flowering. In addition, according to the obtained results, essential oil percentage of the second harvests showed a significant decreasing trend. Overall, results showed that the highest fresh yield per hectare and essential oil were obtained at budding stage and consumption level of 200 kg/ha nitrogen fertilizer.
M. Mahboubi; M.M. Feizabadi; Gh. Haghi; H. Hosseini
Volume 24, Issue 1 , May 2008, , Pages 56-65
Abstract
Oliveria decumbens Vent. (Umbelliferae) is a shrub commonly found in the South East of Iran. Its aerial part is extensively used in herbal medicine. In this study, the antimicrobial activity of O. decumbens essential oil extracted from aerial parts of plant against a panel of microorganisms including ...
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Oliveria decumbens Vent. (Umbelliferae) is a shrub commonly found in the South East of Iran. Its aerial part is extensively used in herbal medicine. In this study, the antimicrobial activity of O. decumbens essential oil extracted from aerial parts of plant against a panel of microorganisms including gram positive, gram negative bacteria, yeast and fungi were assessed by disc diffusion method and micro broth dilution assay. The chemical constitutes of this oil was analyzed by GC. The main components of essential oil are thymol (26.9%), carvacrol (0.25%), p-cymene (13.3%) and γ-terpinene (11%). This oil exhibited strong antifungal activity against filamentous fungi and yeast with average of inhibition zone (AIZ) 34.86 and MIC≤0.25µl ml -1. The effect of 2 µl of essential oil (IZ≥27.3 mm) is larger than Amphotricin B (IZ≤17) against fungi. The gram positive bacteria are more sensitive than gram-negative bacteria (21.9 Vs 18.4). Spore forming bacteria (Bacillus sp.) are resistant to essential oil and the effect of oil against Bacillus sp. had inhibitory effect (MIC>2 µl ml-1). Pseudomonas aeruginosa were more resistant than others (IZO. decumbens oil, i.e. bacteria are more resistant than fungi and gram negative bacteria are more resistant than gram positive bacteria. These effects are more concerned to phenol components especially thymol. Therefore, further studies are required to evaluate in vivo efficacy.