Review of Plant Essential Oils for Plant Pests Management

This paper reviews the origins and classification of plant essential oil resources,along with prevalent extraction techniques for their active constituents.By integrating insights on the utilization of plant essential oils for plant pest management,the comprehensive analysis reveals multiple functionalities exhibited by plant essential oils,including fumigation,contact toxicity,repellent action,antifeedant activity,and growth inhibition.Furthermore,the paper highlights the challenges associated with plant essential oils in plant protection and outlines future research directions,aiming to offer valuable insights for the advancement of botanical insecticides.

Efficacies of four plant essential oils as larvicide, pupicide and oviposition deterrent agents against dengue fever mosquito, Aedes aegypti Linn.(Diptera: Culicidae)

Objective:To evaluate larvicidal,pupicidal and oviposition deterrent activities of four plant essential oils from Alpinia galanga(L.)Willd rhizome,Anethum graveolens L.(An.graveolens)fruit,Foeniculum vulgare Mill.fruit,and Pimpinella anisum L.fruit against Aedes aegypti(Ae.aegypti).Methods:Four essential oils at 1%,5%and 10%concentrations were assessed for insecticidal activity against larvae and pupae of Ae.aegypti,following the procedure of a dipping method assay.Oviposition deterrent activity of four essential oils was evaluated on gravid female of Ae.aegypti by a dual-choice oviposition bioassay.Results:The results revealed that An.graveolens oil provided the strongest larvicidal activity against Ae.aegypti among four tested plant essential oils with the highest mortality rate of 100%and LC_(50)value of-0.3%.From the pupicidal experiment,An.graveolens also showed the highest toxicity against Ae.aegypti pupae with the highest mortality rate of 100%at 72 h and LC_(50)value of2.9%.In addition,10%An.graveolens had an oviposition deterrent effect against Ae.aegypti with effective repellency of 100%and an oviposition activity index of-1.0.Conclusions:An.graveolens oil has a good potential as a larvicidal,pupicidal and oviposition deterrent agent for controlling Ae.aegypti.

Initial Screening of 10 Plant Essential Oils in Vitro Antibacterial Activity Against Blueberry Pathogens

In order to develop natural antistaling agent for blueberries preservation,the antibacterial activities of 10 kinds of plant essential oils were analyzed by oxford-cup test and tube dilution method,and their inhibitory abilities to two kinds of representative Gram bacteria which are Escherichia coli and Staphylococcus aureus,and three kinds of harmful fungi in blueberries,involving Alternaria alternata,Penicillium digitatum and Botrytis cinerea,were tested.The results showed that 7 kinds of essential oils can inhibit the three fungi,among which cinnamon oil,clove oil,anise oil and thyme oil have strong fungi static efficacy.Cinnamon oil and thyme oil can effectively inhibit the Gram-positive bacterium(Staphylococcus aureus);cinnamon oil and masson pine oil are strongly inhibitory to Gram-negative bacterium(E.coli).Cinnamon oil has broad-spectrum ability to inhibit fungi,Gram-negative and positive bacteria,with a minimum inhibitory concentration(MIC)ranging from 0.0391 to 0.1560 L/mL.With strong inhibition effects on fungi,cinnamon oil can be used as a compound base oil and mixed with other essential oils to retain the freshness of blueberries,thus achieving better antibacterial and anti-corrosion effects.

Termiticidal and Biochemical Activity of Combinatorial Essential Oil Ingredients of Tagetes erecta on Indian White Termite Odontotermes obesus

In present investigation, various bio-molecular parameters i.e. glycogen, protein, amino acid, DNA, RNA and lipid, were determined for evaluation of anti-termite efficacy of Tagetes erecta essential oil based combinatorial formulations against Indian white termite Odontotermes obesus. For this purpose, 40% and 80% of 24 hrs of LD50 values of various formulations were provided for treatment of termite workers. Observations were taken at 4 hrs time interval up to 16 hrs to know inhibitory activity of these combinatorial mixtures on termite species Odontotermes obesus. Significant (p > 0.05) alterations were observed in the level above mentioned bio-molecules when termites were treated with different combinatorial essential oils ingredients of Citrus maxima. Combinatorial mixtures of Tagetes erecta essential oils have shown synergistic activity against termites. This study will provide an overall sustainable way to termite control in crop field, gardens and houses. It also suggests use of essential oils as better alternative of synthetic termiticides as these are safer for environmental and human health.

Impact of Asarum Essential Oils on Physiological and Biochemical Indicators of Two Agricultural Pests

[Objective]The paper was to study the effects of asarum essential oils on physiological and biochemical indices of two agricultural pests. [Method]Asarum essential oils were extracted by different methods,and their effects on physiological and biochemical indices related to the structure of body wall（ chitin and phenoloxidase）,the physiological and biochemical indices acting on the nervous system（ Acetylcholinesterase）,and the physiological and biochemical indices acting on the digestive system（ protease,amylase and lipase） of Ostrinia furnacalis and Mythimna seperata were studied. [Result]Asarum essential oils had no effect no chitin content of body wall under the experimental concentration,and had no inhibitory effect but activated effect on polyphenol oxidase activity. Asarum essential oils could act on the nervous system of insect,and had strong inhibitory effect against acetylcholinesterase activity of O. furnacalis larvae,with inhibition rates of 24. 86%- 38. 79%. Asarum essential oils showed a significant activated effect on pepsin activity in midgut,but the activated amplitude became smaller with the prolongation of treatment time. Asarum essential oils showed a significant inhibitory effect on activities of amylase and lipase,indicating that it could play an insecticidal effect by inhibiting activity of amylase and lipase,and it could act on digestive system of insect. [Conclusion]The study laid the foundation for further development of asarum as botanical pesticide.

Antifungal Effect of Plant Extract and Essential Oil

The advancement of phytochemical and phytopharmacological sciences has enabled elucidation of the composition and biological activities of several medicinal plant products including plant extract and essential oils. These products have been widely used around the world since ancient times for the treatment of various disorders such as diabetes, hypertension, peptic ulcer disease, microbial infection, sexual disorder and many more. Its popularity in the modern system of medicine is mainly due to their availability and fewer adverse reactions compared to synthetic drugs. Various scientific investigations have been conducted to look for the potential of the extract from the plant or isolated compounds for the continued use of these products in the treatment and prevention of various kinds of human diseases. It is evident from the available literature and scientific investigations that many plant species possess potential for use as a beneficial therapeutic remedy with multiple pharmacological actions such as analgesic, anti-inflammatory, antipyretic, hypoglycemic, hypotensive, antimicrobial, antiulcer and anticonvulsant activities. The present review aims to provide relevant updated information about certain plant products, its composition, preparation and its fungicidal or fungistatic effects on different species of fungus as evaluated by studies done in the past. It introduces six medicinal plants that have been studied for their antifungal property and are found to be effective. The overall objective is to provide comprehensive information about the use of plant extract and essential oil for treating fungal infections and to explore the evidence supporting its effectiveness in treating fungal diseases without causing any serious adverse reactions.

Effect of Oregano Carvacrol on Growth Performance of Broiler

The product of plant essential oil, oregano carvacrol, was added in the diet of broiler, to study the effect of oregano carvacrol on growth performance of broilers. Using single factor test, 190 663 individuals of healthy AA broilers at 0 day old were randomly divided into two groups, eight repeats in control group and four repeats in experimental group. The broilers in control group were fed with basal diet （containing 10 mg/kg cnramycin and 60 mg/kg salinomycin sodium）, and those in experimental groups were fed with the basal diet adding with 100 mg/kg oregano carvacrol. Compared with control group, the daily gain of broilers in exper- imental group was increased noticeably by 3.41 g/broiler （P 〈 0. 05） ; the slaughter quality was increased remarkably by 143 g/broiler （P 〈 0.05 ） ; the survival rate was increased significantly by 3.01% （ P 〈 0.05 ） ; and the feed gain ratio was reduced markedly by 0.08 （ P 〈 0.05 ）. The paper provided a theoretical basis for application of oregano carvacrol in broiler production.