scholarly journals (408) Effects of Essential Oils on CO2 Assimilation, Stomatal Conductance, and Evapotranspiration of Apple

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1070B-1070 ◽  
Author(s):  
Jason McAfee ◽  
Curt Rom
Keyword(s):  
Plant Growth ◽  
Essential Oils ◽  
Co2 Assimilation ◽  
Clove Oil ◽  
Concentration Effects ◽  
Effective Technique ◽  
Cinnamon Oil ◽  
Fruit Thinning ◽  
Certified Organic ◽  
Organic Fruit

Pesticides and alternative fruit thinners are needed for certified organic fruit growers. Transient reductions in photosynthesis (Pn) have proven an effective technique for fruit thinning. Pesticides can be detrimental to plant growth by Pn reduction. This study was developed to measure plant response to foliar applications of essential oils at 2% concentrations. Treatments were applied to vegetative apple trees grown under controlled environment conditions to study photosynthetic effects. There was no significant effect on Pn for treatments; however, clove oil was very phytotoxic and defoliated all trees in this study. Cinnamon oil and cedarwood oil significantly decreased evapotranspiration and stomotal conductance 1 day after treatment. Differences in plant growth were not significantly different for all treatments excluding clove oil. Studies on concentration effects may determine horticultural usefulness of these compounds.

scholarly journals (159) Effects of Sulfur Compounds on CO2 Assimilation, Evapotranspiration, and Stomatal Conductance of Apple

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1032A-1032 ◽  
Author(s):  
Jason D. McAfee ◽  
Curt R. Rom
Keyword(s):  
Stomatal Conductance ◽  
Plant Growth ◽  
Co2 Assimilation ◽  
Sulfur Compounds ◽  
Potassium Sulfate ◽  
Controlled Environment ◽  
Effective Technique ◽  
Fruit Thinning ◽  
Certified Organic ◽  
Organic Fruit

Pesticides and alternative fruit thinners are needed for certified organic fruit growers. Transient reductions in photosynthesis (Pn) have proven an effective technique for fruit thinning. Pesticides can be detrimental to plant growth by Pn reduction. A two-part study was developed to measure plant response to foliar applications of sulfur compounds. In study 1, 2% concentrations of various sulfur compounds were observed for potential physiological or pesticidal effects. Foliar treatments were applied to vegetative apple trees grown under controlled environment conditions to study photosynthetic effects. No treatments significantly reduced CO2 assimilation (A) and stomatal conductance (gs). Copper sulfate, ammonium sulfate, and potassium sulfate significantly reduced evapotranspiration (Et) 7 days after treatment. No significance was observed for plant growth. In study 2, a 2% potassium sulfate concentration significantly reduced A 22 days after treatment; however, no differences were observed for Et and gs. Differences in plant growth were not significantly different among treatments.

scholarly journals EFFECTS OF VARIOUS ACID COMPOUNDS ON CO2 ASSIMILATION, EVAPOTRANSPIRATION, AND STOMATAL CONDUCTANCE OF APPLE

HortScience ◽  
2005 ◽  
Vol 40 (3) ◽  
pp. 883c-883
Author(s):  
J.D. Mcafee ◽  
C.R. Rom
Keyword(s):  
Stomatal Conductance ◽  
Foliar Application ◽  
Co2 Assimilation ◽  
Model System ◽  
Stem Growth ◽  
Effective Technique ◽  
Fruit Thinning ◽  
Plant Stem ◽  
Certified Organic ◽  
Organic Fruit

Alternative fruit thinners and pesticides are needed for certified organic fruit growers. A transient reduction in photosynthesis has proven to be an effective technique used for fruit thinning. Conversely, pesticides, which reduce Pn may be detrimental to plant growth. This study was developed to measure plant response to foliar applications of various organic acids as potential horticultural chemicals Treatments were applied to vegetative apple trees under controlled environmental conditions to study photosynthetic effects. CO2 assimilation significantly decreased temporarily 3 days after treatment with citric acid. Decreased trends of evapotranspiration were observed for all treatments 1 day after foliar application; however, not significant. Salicylic acid significantly decreased stomatal conductance 1 and 15 days after treatment. Average leaf area was not significantly affected but oxalic acid increased plant stem growth while acetic acid application reduced growth. This model system for screening new and alternative compounds will be a basis to study agents that may have potential to be used as certified pesticides or fruit thinning agents.

scholarly journals Green orchid bee Euglossa dilemma Friese (Insecta: Hymenoptera: Apidae)

EDIS ◽  
2013 ◽  
Vol 2013 (10) ◽  
Author(s):  
Aaron Mullins
Keyword(s):  
Essential Oils ◽  
Volatile Compounds ◽  
Clove Oil ◽  
Orchid Bees ◽  
Cinnamon Oil ◽  
Fact Sheet ◽  
Orchid Bee ◽  
Large Size ◽  
Wood Rot Fungi ◽  
Green Coloration

Green orchid bees are a quite conspicuous and charismatic species. This is mostly due to their large size and bright metallic-green coloration. They are very fast and agile flyers, and can be seen quickly darting from flower to flower separated by long periods of hovering. Male orchid bees collect fragrant volatile compounds from their environment and present them to females by fanning their wings and “spray ventilating” their bouquet for the inspection of prospective mates. In Florida, male green orchid bees are attracted to chemicals produced by certain wood-rot fungi, decomposing vegetation, perfume flowers, and certain essential oils such as clove and cinnamon oil. Male green orchid bees can be quickly and easily attracted and observed by soaking a small piece of paper with clove oil and placing it outside. This 4-page fact sheet was written by Aaron Mullins, and published by the UF Department of Entomology and Nematology, October 2013. http://edis.ifas.ufl.edu/in1013

scholarly journals Effect of essential oils on seed borne Fusarium sp., and seed quality of sesame (Sesamum indicum L.)

2021 ◽  
Vol 11 (1) ◽  
pp. 101-109
Author(s):  
K Girish ◽  
◽  
Chaithra S ◽  
Syeda Fathima ◽  
◽  
...  
Keyword(s):  
Essential Oils ◽  
Mycelial Growth ◽  
Seed Quality ◽  
Sesame Seed ◽  
Sesamum Indicum ◽  
Clove Oil ◽  
Cinnamon Oil ◽  
Rose Oil ◽  
Fusarium Sp

Sesame (Sesamum indicum L.) is as an important oilseed crop and seed borne fungi are reducing the yield as well as quality of the seeds produced. The present study aimed to evaluate the effect of essential oils for control of seed borne fungi as well as enhancement of seed quality of sesame. Fusarium sp., was isolated from sesame seeds by agar plate method. Four essential oils such as camphor oil, cinnamon oil, clove oil and rose oil were screened for their antifungal potential against the isolated Fusarium sp., by poisoned food method. Selected essential oils were tested at different concentrations of 100, 200, 300, 400 and 500 ppm concentrations for their ability to inhibit the mycelial growth of test fungi. All the oils completely inhibited the mycelial growth of test fungi at 500 ppm concentration. The effect of selected essential oils on sesame seed quality was analyzed by standard blotter method. All the four oils increased the germination percentage and seed vigour while the fungal infection was completely inhibited without any phytotoxic effects. Comparatively, clove oil showed the best activity followed by camphor oil, cinnamon oil and rose oil. These results observed of the essential oils indicate the possible usage of them for the sesame seed treatment following further investigations.

scholarly journals Antimicrobial Activity of Commercially Available Essential Oils Against Streptococcus mutans

2012 ◽  
Vol 13 (1) ◽  
pp. 71-74 ◽  
Author(s):  
Bhushan Arun Jawale ◽  
Lalit Kumar D Chaudhari ◽  
Sheeba Sharma ◽  
CD Mounesh Kumar ◽  
Pooja Adwait Kulkarni
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Essential Oils ◽  
Streptococcus Mutans ◽  
Peppermint Oil ◽  
Clove Oil ◽  
Cinnamon Oil ◽  
Lemongrass Oil ◽  
Spearmint Oil

ABSTRACT Introduction Many essential oils have been advocated for use in complementary medicine for bacterial and fungal infections. However, few of the many claims of therapeutic efficacy have been validated adequately by either in vitro testing or in vivo clinical trials. Objective To study the antibacterial activity of nine commercially available essential oils against Streptococcus mutans in vitro and to compare the antibacterial activity between each material. Methodology Nine pure essential oils; wintergreen oil, lime oil, cinnamon oil, spearmint oil, peppermint oil, lemongrass oil, cedarwood oil, clove oil and eucalyptus oil were selected for the study. Streptococcus mutans was inoculated at 37°C and seeded on blood agar medium. Agar well diffusion assay was used to measure antibacterial activity. Zone of inhibition was measured around the filter paper in millimeters with vernier caliper. Results Cinnamon oil showed highest activity against Streptococcus mutans followed by lemongrass oil and cedarwood oil. Wintergreen oil, lime oil, peppermint oil and spearmint oil showed no antibacterial activity. Conclusion Cinnamon oil, lemongrass oil, cedarwood oil, clove oil and eucalyptus oil exhibit antibacterial property against S. mutans. Clinical significance The use of these essential oils against S. mutans can be a viable alternative to other antibacterial agents as these are an effective module used in the control of both bacteria and yeasts responsible for oral infections. How to cite this article Chaudhari LKD, Jawale BA, Sharma S, Sharma H, Mounesh Kumar CD, Kulkarni PA. Antimicrobial Activity of Commercially Available Essential Oils Against Streptococcus mutans. J Contemp Dent Pract 2012;13(1):71-74.

Enzyme‐assisted extraction of essential oils from Syzygium aromaticum

2011 ◽  
Vol 1 (6) ◽  
pp. 248-254
Author(s):  
R. Amudan ◽  
D. V. Kamat ◽  
S. D. Kamat
Keyword(s):  
Essential Oil ◽  
Essential Oils ◽  
Steam Distillation ◽  
Antibacterial Effect ◽  
Chemical Extraction ◽  
Syzygium Aromaticum ◽  
Clove Oil ◽  
Zone Size ◽  
Structure Quality ◽  
Assisted Extraction

The essential oil of clove ( Syzygium aromaticum) holds an important positionamongst widely used essential oils. A typical steam distillation processfor the extraction of clove oil provides a 10.1% yield. Recent studies involvedthe use of enzymes such as pectinase, amylase, lignocellulase, and cellulaseon the powder of clove buds, prior to extraction. The traditional methods ofphysical and chemical extraction are effective but may affect the structure,quality and yield of the phytochemicals extracted. In the current study,hence, enzymes specific for action on the cell wall have been used in the pretreatment prior to extraction, to enhance the quality and yield of the phytochemicalsextracted. The results indicated that all the enzymes, gave morethan 50% higher yield than control in terms of weight of extracted essentialoil. A mixture of the enzymes gave the highest yield of 17.82%. Gas chromatographyresults indicated that the essential oil extracted using amylase hada maximum eugenol content of 70%, in comparison with the eugenol content(62–68%) in the essential oils extracted using the rest of the enzymes.Antibacterial activity of all the extracts was studied on methicillin â€resistantStaphylococcus aureus  (MRSA). The essential oil extracted by using amylaseinhibitedMRSA, showed a zone size of 40 mm, whereas the essential oil extractedby using lignocellulase showed a zone size of 45 mm. The gas chromatogramindicated the maximum number of peaks in this extract, whichcould be producing a combined antibacterial effect on the organism. Thespecific gravity values of the essential oil extracted using lignocellulase andamylase was 1.051 and 1.062, respectively, whereas the control had a specificgravity of 1.015.

scholarly journals Effects of essential oils from thyme, cinnamon and clove on mycelial growth of Colletotrichum acutatum

2010 ◽  
Vol 25 (2) ◽  
pp. 151-156 ◽  
Author(s):  
Natasa Duduk ◽  
Aleksa Obradovic ◽  
Mirko Ivanovic
Keyword(s):  
Essential Oils ◽  
Mycelial Growth ◽  
Petri Dish ◽  
Control Treatment ◽  
Colletotrichum Acutatum ◽  
Dependent Manner ◽  
Cinnamon Oil ◽  
Volatile Phase ◽  
Vitro Effect

Effects of the volatile phase of thyme, cinnamon and clove essential oils on Colletotrichum acutatum were investigated. Mycelial disc was placed in the center of the Petri dish (V=66 ml) containing PDA. Different volumes of either non- or ethanol-diluted essential oils were placed on the inner side of the dish cover to obtain final concentrations of 153, 107, 76, 46, 15, 14, 12, 11, 7.6, 3.82, 1.53, 0.153 and 0.0153 ?l/L of air. The dishes were sealed with Parafilm and incubated in up-side-down position. After 7 days of incubation, mycelial growth was recorded by measuring the colony diameter. If no mycelial growth was recorded, the disc was transferred to a new PDA plate in order to evaluate whether the activity was either fungistatic or fungicidal. Mean growth values were obtained and then converted to inhibition percentage of mycelial growth compared with the control treatment. All the tested essential oils inhibited mycelial growth of C. acutatum in the dose dependent manner. Mycelial growth was totally inhibited by thyme oil in the concentration of 76 ?l/L of air. The same results were obtained by cinnamon and clove oil in the concentration of 107 ?l/L of air. Thyme and cinnamon oil had fungicidal effect in concentrations of 107 and 153 ?l/L respectively. The results obtained provide evidence on the antifungal in vitro effect of the tested essential oils as potential means for the control of C. acutatum.

Phytotoxicity of clove oil and its primary constituent eugenol and the role of leaf epicuticular wax in the susceptibility to these essential oils

Weed Science ◽  
2006 ◽  
Vol 54 (5) ◽  
pp. 833-837 ◽  
Author(s):  
Luke D. Bainard ◽  
Murray B. Isman ◽  
Mahesh K. Upadhyaya
Keyword(s):  
Cell Membrane ◽  
Essential Oils ◽  
Seedling Growth ◽  
Electrolyte Leakage ◽  
Membrane Integrity ◽  
Clove Oil ◽  
Common Lambsquarters ◽  
Redroot Pigweed ◽  
Leaf Epicuticular Wax

Herbicidal activities of clove oil and its primary constituent eugenol on broccoli, common lambsquarters, and redroot pigweed and the role of crystalline leaf epicuticular wax (LEW) in susceptibility and retention of these essential oils were studied. Clove oil (2.5%) and eugenol (1.5%) were applied to leaves of greenhouse-grown broccoli, common lambsquarters, and redroot pigweed seedlings and effects on seedling growth and leaf cell membrane integrity were studied. Compared with eugenol, clove oil caused greater inhibition of seedling growth in all species. Both eugenol and clove oil caused greater loss of membrane integrity and inhibition of seedling growth in redroot pigweed, which has no crystalline LEW, compared with common lambsquarters, which has a thick layer of crystalline LEW. In broccoli seedlings with LEW, clove oil caused greater inhibition of growth than eugenol. Both clove oil and eugenol caused greater electrolyte leakage from broccoli leaves without LEW than in the leaves with LEW. Removal of LEW increased electrolyte leakage, an indicator of cell membrane damage, by 97% in eugenol-treated and 26% in clove oil–treated broccoli leaves. Susceptibility of broccoli seedlings and possibly some weed species may, therefore, be affected by factors (e.g., genetic, environmental) that influence the amount of LEW. Although the presence of LEW greatly reduced the retention of the essential oil solutions, there was no significant difference between the retention of clove oil and eugenol solutions, indicating that differences in their phytotoxicity to broccoli leaves was not due to differential foliar retention.

Effect of the essential oils addition on the rate of bacterial cellulose surface overgrowth by mold fungi

2021 ◽  
Vol 114 ◽  
pp. 43-51
Author(s):  
Marcin Jałoweicki ◽  
Izabela Betlej
Keyword(s):  
Aspergillus Niger ◽  
Essential Oils ◽  
Bacterial Cellulose ◽  
Trichoderma Viride ◽  
Chaetomium Globosum ◽  
Cellulose Film ◽  
Film Sample ◽  
Cinnamon Oil ◽  
Cellulose Pulp ◽  
Cellulose Surface

Effect of the essential oils addition on the rate of bacterial cellulose surface overgrowth by mold fungi. The aim of this study was to determine the effectiveness of protecting films made of bacterial cellulose with essential oils against overgrowth by mold fungi. The cellulose film produced by microorganisms forming a pellicle called SCOBY was modified by introducing into the cellulose pulp essential oils: cinnamon and manuka. Samples of the protected film were treated with mold fungi: Chaetomium globosum, Aspergillus niger and Trichoderma viride. On the basis of the tests conducted, the rate of film overgrowth by mold fungi and the effectiveness criteria of cellulose film protection with essential oils were determined. The addition of cinnamon oil protected the film against the growth of Aspergillus niger and Chaetomium globosum fungi. Manuka oil slowed down the growth of Chaetomium globosum microorganisms on the surface of the bacterial cellulose film sample, but did not protect the samples from overgrowth. The essential oils tested were ineffective against the fungus Trichoderma viride.

scholarly journals Essential oils as potential anti-staphylococcal agents

2018 ◽  
Vol 68 (1) ◽  
pp. 95-107 ◽  
Author(s):  
Szweda Piotr ◽  
Zalewska Magdalena ◽  
Pilch Joanna ◽  
Kot Barbara ◽  
Milewski Sławomir
Keyword(s):  
Antimicrobial Activity ◽  
Essential Oils ◽  
Bovine Mastitis ◽  
Bactericidal Effect ◽  
Dilution Method ◽  
Kinetic Assay ◽  
Cinnamon Oil ◽  
Microtiter Plates ◽  
Cure Rates ◽  
Time Kill

Abstract Antibiotic therapy of staphylococcal mastitis is characterized by significantly lower cure rates compared to infections caused by other microorganisms. Thus, it is necessary to search for new, alternative, non-antibiotic agents that are effective in the eradication of these bacteria. The aim of our research was to investigate the antimicrobial, especially anti-staphylococcal potential of a large collection (n=36) of essential oils (EOs). Investigation of the antimicrobial activity of tested oils was determined by using a serial, twofold dilution method in 96-wells microtiter plates under conditions recommended by the Clinical and Laboratory Standards Institute (CLSI). The preliminary analysis revealed that six oils, namely: Manuka, Thyme, Geranium, Cedar, Cinnamon (from bark) and Patchouli exhibited the highest activity against reference strains of bacteria. Significant anti-staphylococcal potential of these oils has been also confirmed for a group of 18 Staphylococcus aureus, 8 Staphylococcus epidermidis and 5 Staphylococcus xylosus strains isolated from cases of bovine mastitis. Especially high activity was observed for Cedar, Patchouli, Thyme and Manuka oils. The MIC (Minimal Inhibitory Concentration) values for Patchouli oil were in the concentrations range of 0.01 to 0.313% (v/v). The three other oils inhibited the growth of staphylococci isolated from mastitis in the concentrations range of 0.01 to 0.625% (v/v). Oils isolated from Cinnamomum cassia and Pelargonium graveolens revealed a bit lower, but still satisfactory activity (MIC values in the concentrations range of 0.02 to 1.25% (v/v) and from 0.078 to 1.25% (v/v), respectively). In many cases a slightly higher concentration of oils was required to obtain the bactericidal effect in comparison to growth inhibition. The time – kill kinetic assay revealed that the bactericidal effect was achieved after two hours incubation of the reference strain S. aureus PCM 2051 cells with Thyme oil at concentration equal to 2xMIC (1.25% (v/v)) or MIC (0.625% (v/v)). A slightly lower activity was observed in the case of Cinnamon oil, the bactericidal effect was achieved after 8 hours of incubation. The results of our research clearly indicate that some essential oils exhibit a promising antimicrobial activity and can be considered as alternative antistaphylococcal agents.

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