scholarly journals Essential oils on the control of stem and ear rot in maize

2013 ◽  
Vol 43 (11) ◽  
pp. 1945-1951 ◽  
Author(s):  
Glauco Antonio Teixeira ◽  
Eduardo Alves ◽  
Douglas Carvalho Amaral ◽  
José da Cruz Machado ◽  
Fabiano José Perina

Stem and ear rot caused by Stenocarpella maydis are responsible for severe losses in maize production. Treatment of seeds with fungicides may induce environmental damage. Hence, this study aimed to evaluate the effects of essential oils extracted from Cymbopogon winterianus, Thymus vulgaris, Cymbopogon citratus, Corymbia citriodora, Cinnamomum zeylanicum, and Syzygium aromaticum on the development of in vitro S. maydis. In addition, maize seeds were treated with these essential oils to determine their possible mode of action and effects. The oils from S. aromaticum, C. zeylanicum, and T. vulgaris inhibited fungal development at concentrations higher than 0.025%. The oils from S. aromaticum and C. zeylanicum showed seed germination rates of 89.0% and 84.5%, which were higher than that of the control. The oils from S. aromaticum and C. zeylanicum reduced the pathogen incidence in the seeds to 39.0% and 28.0%, respectively. Further, these oils as well as that from T. vulgaris produced lower reduction of maize stand. Scanning electron microscopy examination revealed that essential oils from S. aromaticum and T. vulgaris acted directly on the conidia, impeding germination. The findings suggest that the oils from S. aromaticum, C. zeylanicum, and T. vulgaris are potential alternatives for maize seed treatment in the control of S. maydis.

2017 ◽  
Vol 47 (5) ◽  
Author(s):  
Tamara Leite dos Santos ◽  
Leônidas Leoni Belan ◽  
Diego Cunha Zied ◽  
Eustáquio Souza Dias ◽  
Eduardo Alves

ABSTRACT: Lecanicillium fungicola, which causes Dry bubble disease, induces infections and inflicts major losses in champignon production. The control can be managed through measures of hygiene and use of fungicides; however, in Brazil there are no registered products. This study aimed to estimate the influence of various essential oils extracted from Melissa officinalis, Thymus vulgaris, Origanum vulgare, Eucalyptus globulus, Cinnamomum zeylanicum and Syzygium aromaticum on the in vitro development and their uses. Therefore, analysis was performed of the L. fungicola isolates in vitro and the best oils were tested in vivo. Besides, the Agaricus bisporus - L. fungicola interaction was confirmed by scanning electron microscopy (SEM). Cinnamon and clove oils in concentrations of 0.4% and thyme oil of 0.8% were identified as good growth inhibitors of the pathogenic mycelium. Effective inhibition of the conidial germination was seen in all concentrations by cinnamon oil, and by clove and thyme oils only at 0.4% and 0.8%, respectively. When the essential oils were applied post-infestation in the in vivo experiments the incidence of the disease in the mushrooms was much lower. From the SEM it was clear that 19 hours after the inoculation of A. bisporus with L. fungicola, the spores had already completely germinated, revealing the presence of the infection. Therefore, the findings of this study indicated that the oil extracts of cinnamon, clove and thyme are potential and efficient alternatives in the control of dry bubble disease.


Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1270 ◽  
Author(s):  
Simona Nardoni ◽  
Basma Najar ◽  
Baldassare Fronte ◽  
Luisa Pistelli ◽  
Francesca Mancianti

Saprolegnia spp. water molds severely impact fish health in aquaculture, fish farms and hobby fish tanks colonizing mature and immature stages of fishes, as well as eggs. Considering that there are no drugs licensed for treating and/or control the organism, efficient and environmental low-impact methods to control these oomycetes in aquaculture are needed. The aim of the present report was to evaluate the in vitro sensitivity of Saprolegnia parasitica to essential oils (EOs) from Citrus aurantium L., Citrus bergamia Risso et Poiteau, Citrus limon Burm. f., Citrus paradisi Macfad, Citrus sinensis Osbeck, Cinnamomum zeylanicum Blume, Cymbopogon flexuosum (Nees ex Steud.) Watson, Foeniculum vulgare Mill., Illicium verum Hook.f., Litsea cubeba (Lour.) Pers., Origanum majorana L., Origanum vulgare L., Pelargonium graveolens L’Hér., Syzygium aromaticum Merr. & L.M.Perry, and Thymus vulgaris L., by microdilution test. The most effective EOs assayed were T. vulgaris and O. vulgare, followed by C. flexuosum, L. cubeba and C. bergamia. These EOs could be of interest for controlling Saprolegnia infections. Nevertheless, further safety studies are necessary to evaluate if these products could be dispersed in tank waters, or if their use should be limited to aquaculture supplies.


2018 ◽  
Vol 49 (2) ◽  
pp. 69-77
Author(s):  
J. Mazáková ◽  
M. Zouhar ◽  
P. Sedlák ◽  
E. Zusková ◽  
P. Ryšánek ◽  
...  

Abstract A total of 235 Phytophthora infestans isolates were collected from five regions of the Czech Republic during the growing seasons 2012–2014 and 2016 and examined using the in vitro amended agar method for their sensitivity to metalaxyl-M (MFX), propamocarb-HCl (PCH), and dimethomorph (DMM). A majority of the isolates (50%) were sensitive to MFX. Resistant isolates were found in all four years of the survey; they represented 30% of the samples. The EC50 values of PCH in inhibiting mycelial growth of 65% of the overall isolates were higher than 100 μg ml−1, which indicates the occurrence of insensitivity to PCH in the Czech P. infestans populations. DMM was very effective, and the mycelial growth of all isolates tested was completely suppressed at the concentration of 0.1 μg ml−1. Furthermore, the efficacy of 12 plant essential oils was tested against 20 isolates of P. infestans using the in vitro amended agar method. Essential oils of Cymbopogon winterianus, Litsea cubeba, Mentha spicata, Pelargonium graveolens, Syzygium aromaticum, and Thymus vulgaris were observed to have the highest antifungal activity against P. infestans, with minimal inhibitory concentrations less than or equal to 1 μl ml−1.


2018 ◽  
Author(s):  
Ilias Marmouzi ◽  
El Mostafa Karym ◽  
Rachid Alami ◽  
Meryem El Jemli ◽  
Mourad Kharbach ◽  
...  

AbstractBackgroundTherapy combination is defined as disease treatment with two or more medication to acheive efficacy with lower doses or lower toxicity. Regarding its reported toxicities and efficacy, the Essential Oils (EOs) from Syzygium aromaticum (SA) and Pelargonium graveolens (PG) were combined for in vitro and in vivo assays and toxicities.MethodsThe Essential Oils and mixture were tested for in vivo/in vitro antioxidant and anti-inflammatory activities. The assays included the animal model of acute inflammation (carrageenan model), the protective effect on H2O2/Sodium nitroprissude induced stress in Tetrahymena pyriformis, and the in vitro antioxidant assays.ResultsThe chemical analysis of the investigated Oils has lead to the identification of Eugenol (74.06%), Caryophyllene (11.52%) and Carvacrol acetate (7.82%) as the major element in SA; while PG was much higher in Citronellol (30.77%), 10-epi-γ-Eudesmol (22.59%), and Geraniol (13.95%). In our pharmacological screening of samples, both Oils demonstrated good antioxidant effects. In vivo investigation of the antioxidant activity in the protozoa model (T. pyriformis) demonstrated a lesser toxic effect of EOs mixture with no significant differences when oxidative stress markers and antioxidant enzymes (MDA, SOD and CAT) were evaluated. On the other hand the in vivo model of inflammatory response to carrageenan demonstrated a good inhibitory potential of both EOs. The EOs Mixture demonstrated equivalent bioactivity with lower toxic effect and minimal risk for each compound.ConclusionsThe results from this study indicate that EOs mixture from SA and PG demonstrated promising modulatory antioxidant/anti-inflammatory effect, which suggest an efficient association for therapy.


2007 ◽  
Vol 76 (3) ◽  
pp. 357-361 ◽  
Author(s):  
Š. Faix ◽  
Š. Juhas ◽  
Z. Faixová

The aim of this study was to determine the effects of four essential oils intake by feed, namely Origanum vulgare, Thymus vulgaris, Cinnamomum zeylanicum Ness, and Syzygium aromaticum on antioxidant status in mice in vivo. Essential oils were in the aether oleum form. They were diluted with ethanol absolute mixed with ground pelett (0.1, 0.25, 0.57 and 1% concentration) and thereafter ethanol was evaporated. SOD, GPx activities and TAS were measured in erythrocytes and plasma spectrophotometrically with Ransod, Ransel and TAS kits from RANDOX, respectively. GPX activity showed a significant increase in 0.25% and 0.1% concentration of Origani aetheroleum. The GPx activities were decreased in 1% concentration of Thymi aetheroleum and 0.57% concentration of Cinnamomi aetheroleum and 0.57% concentration of Caryophylli aetheroleum. The total antioxidant status showed a significant decrease in 1 % concentration of Origani aetheroleum and significantly increased in 0.1% concentration. The same results were found in Thymi aetheroleum. Cinnamomi aetheroleum and Caryophylli aetheroleum had not effect on total antioxidant status. SOD activities were not significantly changed after intake of essential oils. In conclusion, our results showed, that concentration of essential oil is very important for antioxidant status and also for metabolism of mice, because a high dose of essential oil has adverse effect on metabolism of mice, representated by a lower growth of the body weight. On the other hand, essential oils at lower concentrations have positive effect on antioxidant status of mice.


2011 ◽  
Vol 74 (4) ◽  
pp. 676-680
Author(s):  
ZHENGJUN XIA ◽  
HONGYAN WU ◽  
PREMILA N. ACHAR

Stenocarpella maydis is the most prevalent ear rot pathogen of maize (Zea mays) in South Africa, the United States, and other countries. Infection and ultrastructure of propagules of S. maydis in maize were observed by light, scanning, and transmission electron microscopy. Two-celled conidia of S. maydis were found in the tissues of husk and kernels. Mycelia colonized inter- and intracellularly in the host tissues. Pycnidia were found abundantly inside the seed tissues of susceptible cultivars; within a single seed, pycnidia propagated preferentially in embryonic tissues. A pycnidium is composed of morphologically different resting spores mingled with some degraded organelles of the host cell. In this study, various enzymatic activities led to cell wall degradation, lacunae in endosperm tissues, and disrupted organelles in susceptible cultivars. In contrast, callose deposition surrounding fungal hyphae was clearly visible in resistant cultivars. Heavy infection was detected by maceration, even though there was no apparent symptom on the seed coat. The saprophytic nature and structurally different forms of propagules could contribute to a long-term survival of this pathogen in the field and during grain storage. Furthermore, S. maydis might pose a threat of diplodiatoxin intoxication to human and domestic animals when infected maize seeds are consumed.


Animals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 352 ◽  
Author(s):  
Pavel Horky ◽  
Sylvie Skalickova ◽  
Kristyna Smerkova ◽  
Jiri Skladanka

Essential oils (EOs) are now a hot topic in finding modern substitutes for antibiotics. Many studies have shown positive results and confirmed their high antibacterial activity both in vitro and in vivo. Deservedly, there is an attempt to use EOs as a substitute for antibiotics, which are currently limited by legislation in animal breeding. Given the potential of EOs, studies on their fate in the body need to be summarized. The content of EO’s active substances varies depending on growing conditions and consequently on processing and storage. Their content also changes dynamically during the passage through the gastrointestinal tract and their effective concentration can be noticeably diluted at their place of action (small intestine and colon). Based on the solubility of the individual EO’s active substances, they are eliminated from the body at different rates. Despite a strong antimicrobial effect, some oils can be toxic to the body and cause damage to the liver, kidneys, or gastrointestinal tissues. Reproductive toxicity has been reported for Origanum vulgare and Mentha arvensis. Several publications also address the effect on the genome. It has been observed that EOs can show both genoprotective effects (Syzygium aromaticum) and genotoxicity, as is the case of Cinnamomum camphor. This review shows that although oils are mainly studied as promising antimicrobials, it is also important to assess animal safety.


Antibiotics ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 272 ◽  
Author(s):  
Ramona Iseppi ◽  
Alessandro Di Cerbo ◽  
Piero Aloisi ◽  
Mattia Manelli ◽  
Veronica Pellesi ◽  
...  

The aim of this study was to analyze the antibacterial activity of four essential oils (EOs), Melaleuca alternifolia, Eucalyptus globulus, Mentha piperita, and Thymus vulgaris, in preventing the development and spread of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae, metallo-beta-lactamase (MBL)-producing Pseudomonas aeruginosa and carbapenemase (KPC)-producing Klebsiella pneumoniae. A total of 60 strains were obtained from the stock collection from the Microbiology Laboratory of Hesperia Hospital, Modena, Italy. Twenty ESBL-producing E. coli, 5 K. pneumoniae, 13 KPC-producing K. pneumoniae, and 20 MBL-producing P. aeruginosa were cultured and reconfirmed as ESBL and carbapenamase producers. Polymerase chain reaction was used for the detection of genes responsible for antibiotic resistance (ESBL and KPC/MBL). Antibacterial activity of the EOs was determined using the agar disk diffusion assay, and minimal inhibitory concentrations (MICs) were also evaluated. Lastly, adhesion capability and biofilm formation on polystyrene and glass surfaces were studied in 24 randomly selected strains. M. alternifolia and T. vulgaris EOs showed the best antibacterial activity against all tested strains and, as revealed by agar disk diffusion assay, M. alternifolia was the most effective, even at low concentrations. This effect was also confirmed by MICs, with values ranging from 0.5 to 16 µg/mL and from 1 to 16 µg/mL, for M. alternifolia and T. vulgaris EOs, respectively. The EOs’ antibacterial activity compared to antibiotics confirmed M. alternifolia EO as the best antibacterial agent. T. vulgaris EO also showed a good antibacterial activity with MICs lower than both reference antibiotics. Lastly, a significant anti-biofilm activity was observed for the two EOs (*P < 0.05 and **P < 0.01 for M. alternifolia and T. vulgaris EOs, respectively). A good antibacterial and anti-biofilm activity of M. alternifolia and T. vulgaris EOs against all selected strains was observed, thus demonstrating a future possible use of these EOs to treat infections caused by ESBL/carbapenemase-producing strains, even in association with antibiotics.


Agronomy ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 656
Author(s):  
Gea ◽  
Navarro ◽  
Santos ◽  
Diánez ◽  
Herraiz-Peñalver

The main aim of this study was to evaluate the use of essential oils (EOs) as an alternative to synthetic fungicides used in the control of cobweb disease of button mushroom (Agaricus bisporus) caused by Cladobotryum mycophilum. The EOs used were obtained by hydrodistillation from five Mediterranean aromatic species (Lavandula × intermedia, Salvia lavandulifolia, Satureja montana, Thymus mastichina, and Thymus vulgaris), analyzed by gas chromatography, and tested in vitro for their antifungal activity against C. mycophilum. In vitro bioassays showed that the EOs obtained from T. vulgaris and S. montana (ED50 = 35.5 and 42.8 mg L−1, respectively) were the most effective EOs for inhibiting the mycelial growth of C. mycophilum, and were also the most selective EOs between C. mycophilum and A. bisporus. The in vivo efficacy of T. vulgaris and S. montana EOs at two different concentrations (0.5 and 1%) were evaluated in two mushroom growing trials with C. mycophilum inoculation. The treatments involving T. vulgaris and S. montana EOs at the higher dose (1% concentration) were as effective as fungicide treatment. The effect of these EOs on mushroom productivity was tested in a mushroom cropping trial without inoculation. They had a strong fungitoxic effect at the first flush. However, a compensatory effect was observed by the end of the crop cycle and no differences were observed in biological efficiency between treatments. The main compounds found were carvacrol and p-cymene for S. montana, and p-cymene and thymol for T. vulgaris. These results suggest that T. vulgaris and S. montana EOs may be useful products to manage cobweb disease if used as part of an integrated pest management (IPM) program.


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