scholarly journals In Vitro Control of Phytophthora infestans and Alternaria solani Using Crude Extracts and Essential Oils from Selected Plants

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Lydia G. Mugao ◽  
Phyllis W. Muturi ◽  
Bernard M. Gichimu ◽  
Ezekiel K. Njoroge
Keyword(s):  
Essential Oils ◽  
Phytophthora Infestans ◽  
Radial Growth ◽  
Fungal Growth ◽  
Alternaria Solani ◽  
Growth Media ◽  
Distilled Water ◽  
Tomato Production ◽  
Crude Extracts

Tomato production is constrained by fungal diseases especially the early and late blight caused by Alternaria solani and Phytophthora infestans, respectively. Control of the two diseases is usually by use of synthetic fungicides which have a long residue effect and also contribute to environmental pollution. Innovative use of biocontrols may offer an eco-friendly and more sustainable solution. This study tested the in vitro efficacy of crude extracts and essential oils of ginger, garlic, tick berry, and Mexican marigold in inhibition of radial growth of A. solani and P. infestans. Extraction of the crude extracts was done using distilled water, ethanol, and methanol solvents, while essential oils were extracted using the dry steam distillation method. The extracts and essential oils were used to amend the growth media of the test pathogens before introducing the precultured pathogens. Sterile distilled water and synthetic fungicide, Ridomil Gold®, were used as positive and negative controls, respectively. Fungal growth inhibition was determined by measuring the radial growth of the test pathogens. Both the crude extracts and the essential oils portrayed some efficacy against the test pathogens. Garlic crude extracts were found to be the most effective, while ethanol was the most suitable extraction solvent. Essential oils were more effective in restricting the pathogen growth than crude extracts. Ginger and garlic oil was found to be as effective as the synthetic fungicide, and thus it was concluded that the two plants have strong antifungal properties with high potential of being utilized as biofungicides. However, effective utilization of these products in farmers’ fields may require industrial formulation to improve their efficiency.

scholarly journals Effect of Some Essential Oils for Limiting Early Blight (Alternaria Solani) Development in Potato Field

2009 ◽  
Vol 49 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Nehal El-Mougy
Keyword(s):  
Essential Oils ◽  
Early Blight ◽  
Disease Incidence ◽  
Foliar Spray ◽  
Fungal Growth ◽  
Alternaria Solani ◽  
Plant Diseases ◽  
Effective Control ◽  
Potato Field

Effect of Some Essential Oils for Limiting Early Blight (Alternaria Solani) Development in Potato FieldThe fungicidal effect of some essential oils againstAlternaria solanione of the species that cause early blight of potato was evaluated underin vitroand field conditions. Effect of carnation, caraway, thyme oils and the chemical fungicide Ridomil MZ 72 at various concentrations on mycelial growth ofA. solaniwas tested. Carnation oil had the strongest and most extensive inhibitory effect on fungal growth. Slightly less effective were caraway and thyme oils followed by the chemical fungicide. Extended field trails for two cultivation seasons proved that the application of essential oils twice as foliar spray had a superior effect to the fungicide treatment for reducing the early blight incidence comparing with untreated control. An opposite relationship between the disease incidence and concentrations of applied essential oils was observed. The increase in potato yield also followed the same trend. The highest reduction in disease incidence and yield increase was recorded in treatments with 1% of carnation, caraway and thyme oils in descending order. Ridomil MZ 72 applied at the dose recommended by manufactories had a low effect in this regard. Essential oils treatments might be used as easily applied, safe and cost effective control methods against such plant diseases.

scholarly journals Essential Oils as Biocontrol Agents of Early and Late Blight Diseases of Tomato under Greenhouse Conditions

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Lydia G. Mugao ◽  
Bernard M. Gichimu ◽  
Phyllis W. Muturi ◽  
Ezekiel K. Njoroge
Keyword(s):  
Late Blight ◽  
Essential Oils ◽  
Early Blight ◽  
Growth Yield ◽  
Alternaria Solani ◽  
Positive Control ◽  
Negative Control ◽  
Distilled Water ◽  
Tomato Production ◽  
Tomato Plants

Tomato production worldwide is usually restrained by various infections, among them mainly the late and early blight caused by Phytophthora infestans and Alternaria solani, respectively. Lately, there has been a growing concern over the use of synthetic fungicides on environmental and food safety, hence the need to explore other alternatives that are friendly to the user, the consumer, and the general environment. This research sought to test the potency of ginger, garlic, and Mexican marigold essential oils against the early and late blight diseases of tomato under greenhouse conditions. A synthetic fungicide (Ridomil Gold®) was used as a positive control while distilled water acted as a negative control. The extraction of essential oils was done by dry steam distillation and then mixed with tween twenty before being topped up with sterile distilled water. They were then used to spray tomato plants that had been inoculated with A. solani and P. infestans isolates under greenhouse conditions. The tomato plants were evaluated for growth, yield, and disease severity. The data obtained was subjected to ANOVA and separation of means was conducted using Student–Newman–Keul (SNK) test at 95% level of confidence. The three essential oils had a significant potency against the two diseases which is comparable to the synthetic fungicide. Marigold essential oil was also found to have a significant impact on the general growth of sprayed tomato plants. Essential oils of the three plants can be further explored as alternative products management of the two diseases.

scholarly journals Efficacy of coupling gamma irradiation with calcium chloride and lemongrass oil in maintaining guava fruit quality and inhibiting fungal growth during cold storage

2018 ◽  
Vol 30 (1) ◽  
pp. 67-78 ◽  
Author(s):  
Ramadan A. Hassanein ◽  
Ehab A. Salem ◽  
Ahmed A. Zahran
Keyword(s):  
Vitamin C ◽  
Fruit Quality ◽  
Cold Storage ◽  
Fungal Growth ◽  
Alternaria Solani ◽  
Titratable Acidity ◽  
Soluble Solids ◽  
Γ Irradiation ◽  
Lemongrass Oil

AbstractThis study was performed to explore the efficacy of combining more than one postharvest treatment in maintaining some quality attributes and reducing fungal pathogenicity in cold-stored guava fruits. The investigated postharvest treatments included the control, CaCl2(4%), lemongrass oil (2 dm3kg−1), gamma (γ) irradiation (0.2, 0.4 and 0.6 kGy), 0.4 kGy γ irradiation + CaCl2(4%), and 0.4 kGy γ irradiation + lemongrass oil (2 dm3kg−1). The studied physiochemical attributes included weight loss, decay percentage, fruit firmness, total soluble solids (TSS), titratable acidity (TA), and vitamin C content. Different fungal species were also isolated from decayed fruits and were identified asAlternaria alternata,Alternaria solani,Aspergillus niger,Botrytis cinerea,Fusarium solaniandRhizopus stolonifer. The severity of infection for the different fungi was determined, and anin vitroantifungal assay was conducted for lemongrass oil. All the investigated treatments generally reduced decay and water loss percentages, and controlled TSS, TA and vitamin C decrements that occurred during cold storage. On the other hand, higher irradiation doses generally increased fruit softness, and the 0.4 kGy γ dose did not contribute to the overall fruit quality when coupled with CaCl2and lemongrass oil, compared to CaCl2and lemongrass oil treatments alone.

Combinational inhibitory action of essential oils and gamma irradiation for controlling Aspergillus flavus and Aspergillus parasiticus growth and their aflatoxins biosynthesis in vitro and in situ conditions

2021 ◽  
pp. 108201322110530
Author(s):  
Hanan H Abdel-Khalek ◽  
Ali AI Hammad ◽  
Reham MMA El-Kader ◽  
Khayria A Youssef ◽  
Dalia AM Abdou
Keyword(s):  
Essential Oils ◽  
Aspergillus Flavus ◽  
Aspergillus Parasiticus ◽  
Fungal Growth ◽  
Storage Period ◽  
Complete Removal ◽  
Γ Irradiation ◽  
Star Anise ◽  
In Situ Conditions

The purpose of this study was to investigate the effects of certain essential oils (star anise, lemon leaves, marjoram, fennel, and lavender) on the fungal growth of Aspergillus flavus and Aspergillus parasiticus and their production of aflatoxin B1 (AFB1). The degree of suppression of the aflatoxigenic strains’ growth and their production of AFB1 is mainly affected by the kind and the concentration of the tested essential oils (EOs). Star anise essential oil had the lowest minimum inhibitory concentration (0.5 and 1.0 μL/mL) against A. flavus and A. parasiticus, respectively, so it was the best among the five different oils. The study of liquid chromatography with tandem mass spectrometry revealed that star anise EO resulted in a 98% reduction in AFB1 without a breakdown of AFB1 products after treatment thus the complete removal of AFB1 was done without any toxic residues. The combination showed a synergistic effect, the combinational treatment between γ-irradiation at a low dose (2 kGy) and star anise EO at concentrate 0.5 μL/g destroyed A. flavus and A. parasiticus inoculated (individually) in sorghum and peanut, respectively throughout the storage period (8 weeks).

scholarly journals Effective medium for in vitro sprouting of the buds and multiplication of the plantlets, and identification of the fungal contaminant associated with the explants of Gnetum

2021 ◽  
Vol 16 (2) ◽  
pp. 001-013
Author(s):  
Abwe Mercy Ngone ◽  
Lawrence Monah Ndam ◽  
Rita Mungfu Njilar ◽  
Doungous Oumar ◽  
Thomas Eku Njock
Keyword(s):  
Culture Medium ◽  
Culture Media ◽  
Fungal Growth ◽  
Growth Media ◽  
Fungal Contamination ◽  
Surface Sterilization ◽  
Pure Cultures ◽  
Nodal Cuttings ◽  
Baseline Information

Plant tissue culture requires the optimization of growth media. Gnetum, known locally in Cameroon as “Eru” is an indigenous gymnospermous vegetable with diverse medicinal, nutritional, cultural and socio-economic values. This resource is over-exploited and expected to neighboring countries, resulting to increased scarcity in the forest. Preliminary work on the in vitro culture of nodal cuttings was faced by the problem of fungal contamination. It was therefore necessary to isolate and identify the fungal contaminant, optimize the surface sterilization of field material and compose an appropriate medium for sprouting. Pure cultures of the fungus were obtained and grown on Potato Dextrose Agar (PDA) and Sabouraud Dextrose Agar (SDA). The identification was based on the appearance of the fungal growth on plates and also on the microscopic view. This was affected by the use of keys. Gnetum explants were disinfected with the various concentrations of disinfectants, preceded in some instances by pre-treatments, as well as incorporating fungicides in the culture medium. Two different culture media were employed: the Woody Plant Medium (WPM) and the Murashige and Skoog (MS) based establishment medium (Y-1). Gnetum was found to live in association with a complex of Microsporum species. The level of contamination of cultures was reduced from 100% to 40% when pre-treated before disinfection and even lower to 10% by incorporating fungicides in the medium. Sprouting was observed in WPM. This study provides baseline information on the in vitro propagation of Gnetum and thus opens up avenues for more research to be carried out in this field.

scholarly journals Effects of Temperature and pH on Fusarium oxysporum and Soybean Seedling Disease

Plant Disease ◽  
2019 ◽  
Vol 103 (12) ◽  
pp. 3234-3243
Author(s):  
David R. Cruz ◽  
Leonor F. S. Leandro ◽  
Gary P. Munkvold
Keyword(s):  
Fusarium Oxysporum ◽  
Root Rot ◽  
Radial Growth ◽  
Culture Media ◽  
Fungal Growth ◽  
Artificial Culture ◽  
Vitro Assay ◽  
Seedling Disease ◽  
Soybean Seedlings

Fusarium oxysporum (Fo) is an important pathogen that reduces soybean yield by causing seedling disease and root rot. This study assessed the effects of pH and temperature on Fo fungal growth and seedling disease. In an in vitro assay, 14 Fo isolates collected from symptomatic soybean roots across Iowa in 2007 were grown on artificial culture media at five pH levels (4, 5, 6, 7, and 8) and incubated at four temperatures (15, 20, 25, or 30°C). In a rolled-towel assay, soybean seeds from Fo-susceptible cultivar Jack were inoculated with a suspension of a pathogenic or a nonpathogenic Fo isolate; both isolates were previously designated for their relative aggressiveness in causing root rot at 25°C. The seeds were placed in rolled germination paper, and the rolls were incubated in all combinations of buffer solutions at four pH levels (4, 5, 6, and 7), and four temperatures (15, 20, 25, or 30°C). There was a significant interaction between temperature and pH (P < 0.05) for in vitro radial growth and root rot severity. Isolates showed the most in vitro radial growth after incubation at pH 6 and 25°C. For the rolled-towel assay, the pathogenic isolate caused the most severe root rot at pH 6 and 30°C. Gaussian regression analysis estimates for optimal conditions were pH 6.3 at 27.1°C for maximal fungal growth and pH 5.9 at 30°C for maximal root rot severity. These results indicate that optimal pH and temperature conditions are similar for Fo growth and disease in soybean seedlings and suggest that Fo may be a more important seedling pathogen when soybeans are planted under warm conditions in moderately acidic soils.

scholarly journals BIOASSAY OF BOTANICAL OILS AGAINST ALTERNARIA SOLANI

2018 ◽  
Vol 10 (4) ◽  
pp. 19
Author(s):  
Tahira Parveen ◽  
Kanika Sharma
Keyword(s):  
Essential Oils ◽  
Control Plant ◽  
Alternaria Solani ◽  
Pathogenic Fungi ◽  
Phytopathogenic Fungi ◽  
Ocimum Sanctum ◽  
Good Potential ◽  
Ocimum Tenuiflorum ◽  
Whatman Paper

Objective: In vitro antifungal activity of six essential oils of 1. Ocimum tenuiflorum (Purple leaves/Krishna Tulsi) 2. Cymbopogon citrates (Nimbu ghas), 3. Origanum majorina (Sweet majoram), 4. Ocimum citriodorum (Nimbu tulsi), 5. Ocimum bascillicum (Gulal tulsi), and 6. Ocimum sanctum (Green leaves/Shree tulsi) were investigated against economically important phytopathogenic fungi, Alternaria solani, isolated from infected chilly. Methods: The experiment was carried out by Whatman paper disc method using Whatman paper No.3 on Potato Dextrose Agar with three replicates. Five concentrations of each essential oils i.e., 20, 40, 60, 80 and 100% were assayed against the test fungus. The experiment was carried out at 27ᵒC and mycelial growth was measured after every third day, upto 15 d using statistical method.Results: It is an evident from this study that all the oils used in this study are inhibiting test fungi, oil of O. bascillicum and O. sanctum are completely (100%) inhibiting test fungi.Conclusion: It may be concluded from the above study that all the taken oils have a good potential to control plant pathogenic fungi and these could be considered for developing a new fungicide.

scholarly journals In vitro formation of Ca-oxalates and the mineral glushinskite by fungal interaction with carbonate substrates and seawater

2005 ◽  
Vol 2 (3) ◽  
pp. 277-293 ◽  
Author(s):  
K. Kolo ◽  
Ph. Claeys
Keyword(s):  
Raman Spectroscopy ◽  
Fungal Growth ◽  
Growth Media ◽  
Mineral Formation ◽  
Airborne Spores ◽  
Thin Sections ◽  
Metal Recycling ◽  
Textural Changes

Abstract. This study investigates the in vitro formation of Ca-oxalates and glushinskite through fungal interaction with carbonate substrates and seawater as a process of biologically induced metal recycling and neo-mineral formation. The study also emphasizes the role of the substrates as metal donors. In the first experiment, thin sections prepared from dolomitic rock samples of Terwagne Formation (Carboniferous, Viséan, northern France) served as substrates. The thin sections placed in Petri dishes were exposed to fungi grown from naturally existing airborne spores. In the second experiment, fungal growth and mineral formation was monitored using only standard seawater (SSW) as a substrate. Fungal growth media consisted of a high protein/carbohydrates and sugar diet with demineralized water for irrigation. Fungal growth process reached completion under uncontrolled laboratory conditions. The newly formed minerals and textural changes caused by fungal attack on the carbonate substrates were investigated using light and scanning electron microscopy (SEM-EDX), x-ray diffraction (XRD) and Raman spectroscopy. The fungal interaction and attack on the dolomitic and seawater substrates resulted in the formation of Ca-oxalates (weddellite CaC2O4·2(H2O), whewellite (CaC2O4·(H2O)) and glushinskite MgC2O4·2(H2O) associated with the destruction of the original hard substrates and their replacement by the new minerals. Both of Ca and Mg were mobilized from the experimental substrates by fungi. This metal mobilization involved a recycling of substrate metals into newly formed minerals. The biochemical and diagenetic results of the interaction strongly marked the attacked substrates with a biological fingerprint. Such fingerprints are biomarkers of primitive life. The formation of glushinskite is of specific importance that is related, besides its importance as a biomineral bearing a recycled Mg, to the possibility of its transformation through diagenetic pathway into an Mg carbonate. This work is the first report on the in vitro formation of the mineral glushinskite through fungal interaction with carbonate and seawater substrates. Besides recording the detailed Raman signature of various crystal habits of Mg- and Ca-oxalates, the Raman spectroscopy proved two new crystal habits for glushinskite. The results of this work document the role of microorganisms as metal recyclers in biomineralization, neo-mineral formation, sediment diagenesis, bioweathering and in the production of mineral and diagenetic biomarkers. They also reveal the capacity of living fungi to interact with liquid substrates and precipitate new minerals.

scholarly journals In vitro inhibition of radial growth, sporulation and germination of Alternaria solani by some fungicides

Agro-Science ◽  
2015 ◽  
Vol 13 (1) ◽  
pp. 31 ◽  
Author(s):  
FN Ugwuja ◽  
JNC Maduewesi ◽  
KI Ugwoke ◽  
JI Mbadianya
Keyword(s):  
Radial Growth ◽  
Alternaria Solani

In Vitro efficacy of essential oils on mycelial growth of Magnaporthe griseaca using blast in basmati rice

2016 ◽  
Vol 1 (02) ◽  
pp. 170-173
Author(s):  
Vipin Kumar ◽  
Prashant Mishra ◽  
Joginder Singh ◽  
Raju .
Keyword(s):  
Essential Oils ◽  
Radial Growth ◽  
Mycelial Growth ◽  
Basmati Rice ◽  
Pyricularia Grisea ◽  
Syzygium Aromaticum ◽  
Clove Oil ◽  
Neem Oil ◽  
Poison Food Technique

Management of Pyriculari agrisea by eco-friendly approaches is promising. In this study the essential oils from Coriander sativum (Coriander), Azadirachta indica (Neem) and Syzygium aromaticum (Clove) were tested against Pyricularia grisea in vitro by poison food technique. The pure culture of P. grisea was allowed to grow at 300ppm, 500ppm and 1000ppm concentration of essential oils on PDA medium. Clove oil was found most effective to inhibit mycelial growth completely at 300, 500 and 1000ppm after72 hrs, 96 hrs and 120 hrs. Next effective oil was observed neem oil followed by coriander oil. This indicated that clove oil is most effective against P. oryzae pathogen. Neem and coriander oil is less effective. The results of the current study indicated that each of the three essential oils tested, reduced the radial growth of P. oryzae.

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