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1.
Neem oil (NO) and pungam oil (PO) based emulsifiable concentrate (EC) formulations,viz., neem oil 60 EC (acetic acid) [NO 60 EC(A)], neem oil 60 EC (citric acid) [NO 60 EC(C] and neem oil + pungam oil 60 EC (citric
acid) [NO+PO 60 EC(C)], which had been developed at Tamil Nadu Agricultural University, were evaluated for their efficacy
against sheath rot of rice. All three formulations effectively inhibited the mycelial growth of the pathogen,Sarocladium oryzae, underin vitro conditions. There was no significant difference between efficacy of the freshly prepared and stored formulations in arresting
the growth ofS. oryzae; efficacy was maintained even after 9 months of storage. These formulations effectively controlled rice sheath rot and led
to increased yield in five field trials. Among the various treatments, the formulation NO 60 EC(A) achieved the highest grain
yield in four out of five field trials, with a pooled mean grain yield of 4684 kg/havs 3882 kg/ha in the control. NO 60 EC(A) achieved the maximum cost-benefit ratio of 1:4.8, followed by NO+PO 60 EC(C), with
1:3.3. 相似文献
2.
De-Ling Ma Yoshito Suzuki Hiroaki Takeuchi Tomonari Watanabe Mami Ishizaki 《Phytoparasitica》2005,33(5):506-514
Two extracts from neem (Azadirachta indica A. Juss. (Meliaceae)) seeds, azadirachtin and oil, and a mixture of neem oil and abamectin, were tested on second-instar
nymphs of the rice bugLeptocorisa chinensis (Dallas) (Hemiptera: Alydidae). To clarify the effect of spraying coverage on bioefficacy of test materials, experiments
were conducted under choice and no-choice conditions in field cages. In a choice test, treatment with the mixture of neem
oil and abamectin was most effective in reducing the survival ofL. chinensis, followed by azadirachtin at 60 ppm, 30 ppm and 3% neem oil, whereas all treatments except neem oil caused 100% mortality
within 3 weeks in a no-choice test. When second-instar nymphs had choices of treated and untreated plants within a treatment,
no differences in yield and sum of dead and stained grains were found between those two choices, indicating that nymphs neither
caused significant reduction in yield nor reduced the quality of untreated plants. Regardless of treatment, the difference
in overall yield between treated and untreated plants under choice conditions was not statistically significant (P>0.05). Our results indicate that neem-based formulations, used alone or in combination with abamectin, have the potential
to be integrated into the existing programs to control the rice bug.
http://www.phytoparasitica.org posting Aug. 28, 2005. 相似文献
3.
Charles Adarkwah Daniel Obeng-Ofori Cornel Adler Carmen Büttner Christoph Reichmuth Matthias Schöller 《Phytoparasitica》2011,39(3):223-233
The compatibility and protectant potential of Calneem® oil derived from the neem tree Azadirachta indica and two parasitoids, Habrobracon hebetor and Venturia canescens, for the control of the rice moth Corcyra cephalonica (Stainton) (Lepidoptera: Pyralidae) and the tropical warehouse moth Cadra cautella Walker (Lepidoptera: Pyralidae) in stored rice and wheat, were evaluated in the laboratory. Calneem® oil (= neem oil) is a biopesticide produced, registered and marketed in Ghana by AQUA AGRIC Community Projects (AACP/Caldor Ghana Ltd., Tema). It contains 0.3% azadirachtin as its major active ingredient. The oil was emulsified with water using 0.07% soap. Fourth instar moth larvae were held in grain treated with neem oil only, grain treated with one of the parasitoids only, grain treated with a combination of neem and one of the parasitoids, and a control with untreated grain. Neem oil was applied at concentrations from 5,000 to 30,000 ppm. All samples were kept in growth cabinets maintained at 25°C and 65–70% r.h. Adult emergence was recorded after 4 weeks. Parasitoid or neem treatments alone reduced the emergence of C. cephalonica and C. cautella. In general, parasitoid releases were as effective as a combination of neem oil and parasitoids. At the lowest dose, 5,000 ppm, the combination of neem and parasitoid was more effective than the neem alone. The number of adults of H. hebetor and V. canescens that emerged in rice containing either parasitoids alone or in combination with neem oil was similar. This indicates minimal or no adverse effect of neem oil on the two parasitoids. It is thus possible to incorporate neem oil in a well-designed pest management program with parasitoids. 相似文献
4.
An increase of 11–31% of dry mycelial mass was observed along with a slight decrease (5–10%) in aflatoxin Bi production in
5-day-old aflatoxigenicAspergillus spp. submerged cultures containing either 0.5 ml or 1.0 ml clarified neem oil (CNO) in 0.1 % Triton solution. Fungal growth
and aflatoxin B1 production were also determined in potato-dextrose-agar petri plate cultures inoculated with aflatoxigenicAspergillus spp. containing an atmosphere of volatiles emitted from 0.25 ml, 0.5 ml, and 1.0 ml CNO added to the plates. After 5 days’
incubation, fungal radial growth was reduced by 7–29% and aflatoxin B1 production by 0–67%. GC/MS analysis of the head space volatiles of the CNO indicated that the reduction of fungal growth
and aflatoxin B1 was probably due to low molecular weight hydrocarbons, aldehydes, alcohols, and sulfur compounds emitted at 30°C in the dry
culture. These results suggest that volatiles emitted from CNO at 30° C in plate cultures were more fungistatic and consequently
inhibited aflatoxin production more than neem oil added in liquid cultures. 相似文献
5.
Populations of intracellular symbiotes declined significantly in brachypterous females of the brown planthopper,Nilaparvata lugens (Stål), which were stressed during nymphal development by caging them on IR20 rice plants treated with 3% neem oil, 5% neem seed kernel aqueous extract, or 10% neem cake aqueous extract. In addition, nymphs grew poorly and symbiote populations in prospective females declined, when reared on rice plants grown in soil treated with neem cake; this indicates systemic action of bioac-tive neem constituents. Addition of custard-apple oil to neem oil did not enhance the inhibitory effects. The effects of neem derivatives on the symbiotes may be either host-mediated — possibly through disturbed neuroendocrine homeostasis, or direct — leading to perturbations of host-symbiote equilibrium. 相似文献
6.
DL-α-Difluoromethylornithine (DFMO), a specific suicide inhibitor of the polyamine biosynthetic enzyme ornithine decarboxylase
(EC 4.1.1.17), strongly inhibited mycelial growth and sporidial formation of the wheat pathogen,Neovossia indica, in vitro, while DL-α-difluoromethylarginine (DFMA), the analogous suicide inhibitor of arginine decarboxylase (EC 4.1.1.19), did not.
The inhibited mycelial growth and sporidial formation were not only restored by putrescine (polyamine) addition, but were
actually enhanced in the putrescine + DFMO cultures. Besides altering mycelial growth and morphology, DFMO also reduced the
cell size drastically. The inhibition of fungal polyamine biosynthesis is discussed in relation to selective control of plant
disease. 相似文献
7.
Neem oil (Azadirachta indica) nanoemulsion--a potent larvicidal agent against Culex quinquefasciatus
BACKGROUND: Nanoemulsion composed of neem oil and non‐ionic surfactant Tween 20, with a mean droplet size ranging from 31.03 to 251.43 nm, was formulated for various concentrations of the oil and surfactant. The larvicidal effect of the formulated neem oil nanoemulsion was checked against Culex quinquefasciatus. RESULTS: O/W emulsion was prepared using neem oil, Tween 20 and water. Nanoemulsion of 31.03 nm size was obtained at a 1:3 ratio of oil and surfactant, and it was found to be stable. The larger droplet size (251.43 nm) shifted to a smaller size of 31.03 nm with increase in the concentration of Tween 20. The viscosity of the nanoemulsion increased with increasing concentration of Tween 20. The lethal concentration (LC50) of the nanoemulsion against Cx. quinquefasciatus was checked for 1:0.30, 1:1.5 and 1:3 ratios of oil and surfactant respectively. The LC50 decreased with droplet size. The LC50 for the ratio 1:3 nanoemulsions was 11.75 mg L?1. CONCLUSION: The formulated nanoemulsion of 31.03 nm size was found to be an effective larvicidal agent. This is the first time that a neem oil nanoemulsion of this droplet size has been reported. It may be a good choice as a potent and selective larvicide for Cx. quinquefasciatus. Copyright © 2011 Society of Chemical Industry 相似文献
8.
The pest control potential demonstrated by various extracts and compounds isolated from the kernels and leaves of the neem plant (Azadirachta indica) A. Juss. (Meliaceae) seem to be of tremendous importance for agriculture in developing countries. Laboratory and field trial data have revealed that neem extracts are toxic to over 400 species of insect pests some of which have developed resistance to conventional pesticides, e.g. sweet potato whitefly (Bemisia tabaci Genn. Diptera: Aleyrodidae), the diamond back moth (Plutella xylostella L. Lepidoptera: Plutellidae) and cattle ticks (Amblyomma cajennense F. Acarina: Ixodidae andBoophilus microplus Canestrini. Acarina: Ixodidae). The compounds isolated from the neem plant manifest their effects on the test organisms in many ways, e.g. as antifeedants, growth regulators, repellents, toxicants and chemosterilants. This review strives to assess critically the pest control potential of neem extracts and compounds for their use in the tropics. This assessment is based on the information available on the wide range of pests against which neem extracts and compounds have proven to be toxic, toxicity to non-target organisms, e.g. parasitoids, pollinators, mammals and fish, formulations, stability and phytotoxicity. 相似文献
9.
Field trials on upland cotton (Gossypium hirstum L.) during its reproductive phase were used to assess the toxicity of several biorational pesticides and chemicals to Helicoverpa armigera (Hübner) and H. puntigera Wallengren, as well as major predators at Dalby, Queensland, Australia. Moderate rate-dependent control was obtained in plots treated with neem (Azadirachta indica A. Juss) seed extract-azadirachtin (Aza) at rates of 30, 60 and 90 g/ha. Plots treated with Talstar EC (bifenthrin) applications achieved the best results, followed by treatment with alternation of chemicals (methomyl, bifenthrin, thiodicarb and endosulfan) and biorational insecticides (neem oil, azadirachtin and Bacillus thuringiensis kurstaki var. Berliner). Predators, including lady beetles, lacewings, spiders and predatory bugs, were insensitive to Aza, tooseendanin (Tsdn) andBT applications. In contrast, chemicals were very destructive of predators. All treatments provided some protection from infestation of H. armigera and H. puntigera. The effect of Aza on Helicoverpa spp. was reflected in a relatively higher yield of seed cotton harvested from Aza-treated plots compared with the control, but chemical control achieved significantly higher yields than any other treatment. 相似文献
10.
Laboratory assays were done to evaluate the effect of neem seed kernel extract (Azadirachta indica A. Juss),Vitex negundo L. (Lamiales: Verbenaceae) leaf extract, andBacillus thuringiensis (Berliner), applied separately or together, on nutritional indices of the rice leaffolderCnaphalocrocis medinalis (Guenée) (Lepidoptera: Pyralidae). All three biopesticides suppressed feeding and larval growth and low concentrations affected
the larval performance. The combined effect of the three biopesticides resulted in a considerable decrease in nutritional
indices, indicating strong deterrence. Dose response relationships were established with respect to frass production and larval
growth. The efficiency of conversion of ingested and digested food was considerably reduced. 相似文献
11.
Y. Gao X. D. Zeng B. Ren J. R. Zeng T. Xu Y. Z. Yang X. C. Hu Z. Y. Zhu L. M. Shi G. Y. Zhou Q. Zhou X. M. Liu Y. H. Zhu 《Plant pathology》2020,69(2):259-271
Rice blast, caused by the fungus Magnaporthe oryzae, can result in notable yield losses in rice production. The objective of this study was to investigate the potential of a rice endophytic isolate, Streptomyces albidoflavus OsiLf-2, on the control of rice blast and the possible mechanisms involved. In vitro assays displayed a variety of antagonistic effects of OsiLf-2 against different physiological races of M. oryzae, with peak mycelial growth inhibition ranging from 74.1% to 83.0%. In vivo tests of OsiLf-2 showed 18.0% and 19.6% reduction in disease index in greenhouse and field conditions, respectively. The stable active metabolites in its cell-free culture filtrate inhibited the mycelial growth, spore germination and appressorial formation of M. oryzae in a dose-dependent manner. They also possessed strong antifungal capacities toward various phytopathogens in vitro. OsiLf-2 secreted multiple antimicrobial compounds, cell wall degradation enzymes, siderophore, plant hormones, and 1-aminocyclopropane-1-carboxylate deaminase, which might function in direct or indirect resistance to M. oryzae. In addition, a variety of defence responses were induced in OsiLf-2-treated rice, including hydrogen peroxide (H2O2) accumulation, callose deposition, defence-related enzymes activation, and elevated expression of salicylic acid (SA) and jasmonic acid (JA) pathways genes, which might contribute in resisting pathogen attack. The significant biological control activity and host defence-stimulation ability of OsiLf-2 suggest that this endophytic actinobacterial strain could be a promising candidate in the management of rice blast disease. 相似文献
12.
The mobility of alachlor from alginate-encapsulated controlled-release (CR) formulations was investigated in two contrasting soil profiles. Two CR formulations of alachlor were prepared with the following components (1) base—sodium alginate+kaolin+‘Tween’ 20 (1+10+0·5 by mass) and (2) base+40 g kg−1 linseed oil. These were compared to technical grade alachlor and to a commercial alachlor EC formulation (‘Lasso’ 4EC). All herbicide treatments were labeled with [14C]alachlor and were applied to duplicate soil columns that were composed of a surface and a subsoil horizon. Each horizon was packed to a depth of 12·5 cm, giving a total column length of 25 cm. The columns were leached with 21 cm (420 ml) to 30 cm (600 ml) of 0·01M calcium chloride for a period of 7 to 10 days. Alachlor leaching from the EC formulations was the same as that from the technical material in both soils: 33% in the Evesboro and 10% in the Conover soil. The CR-Oil formulation leached 4 and 2% of the applied [14C]alachlor, compared to 12 and 3% for the CR-N formulation for the Evesboro and Conover soils, respectively. The CR-Oil formulation also increased the amount of [14C]alachlor retained in the soil surface horizon (105–114%), compared to CR-N (39–45%), technical material (14–23%) and EC (12–17%). 相似文献
13.
14.
S. Senthil Nathan K. Kalaivani Paul Gene Chung 《Pesticide biochemistry and physiology》2005,81(2):113-122
The effect of neem (Azadirachta indica) limonoids azadirachtin, salannin, deacetylgedunin, gedunin, 17-hydroxyazadiradione, and deaceytlnimbin on gut enzyme activity of the rice leaffolder larvae was investigated. When fed a diet of rice leaves treated with limonoids in bioassays, gut tissue enzymes—acid phosphatases (ACP), alkaline phosphatases (ALP), and adenosine triphosphatases (ATPase) activities of rice leaffolder (Cnaphalocrocis medinalis) larvae are affected. Azadirachtin was most potent in all experiments. Larvae that were chronically exposed to limonoids showed a reduction in weight (59-89%) and exhibited a significant reduction in ACP, ALP, and ATPase activities. These results indicate neem limonoids affects gut enzyme activities. These effects are most pronounced in early instars. 相似文献
15.
Neem(Azadirachta indica A. Juss.) seed kernel (NSK) extracts,viz., NSK aqueous suspension (NSKS), ethanolic extract of NSK (EtOH. NSK), hexane extract of NSK (neem oil), ethanolic extract
of the hexane extract (EtOH. oil) and acetone extract of deoiled NSK powder (Acet. DNSKP) at 1.25-20% concentrations, and
pure azadirachtin at 1.25-10 ppm, were evaluated as oviposition deterrents toBactrocera cucurbitae (Coq.) andB. dorsalis Hendel. NSKS at ≥5% under choice test conditions, and at all concentrations (≥1.25%) in no-choice tests significantly deterred
oviposition in both species. Similarly, EtOH. NSK was significantly active at all the concentrations tested for both species
in choice and no-choice tests. However, with neem oil and EtOH. oil sensitivities of the two species differed considerably.
Both extracts deterred oviposition byB. cucurbitae at all the concentrations tested under both choice and no-choice test conditions. On the other hand, withB. dorsalis, neem oil was significantly deterrent only at 20% in both test regimes and at 5% and 20% for EtOH. oil under choice and no-choice
test conditions, respectively. Acet. DNSKP significantly deterred oviposition by both species at all concentrations tested.
Azadirachtin failed to deter oviposition in either species. 相似文献
16.
K. Rajappan C. Ushamalini N. Subramanian V. Narasimhan A. Abdul Kareem 《Phytoparasitica》2000,28(2):109-113
Leaf extracts ofVitex negundo L,Synadenium grantii Hook. f. andProsopis juliflora (SW) DC, and cake ofAzadirachta indica A. Juss. were evaluated for their efficacy in reducing the population of the green leafhopper,Nephotettix virescens (Distant), and its transmission of rice tungro virus under field conditions. All four plant species tested reduced the population
of the vector significantly in both the nursery and main field. The lowest population of the vector was recorded with application
of neem cake at 5 kg/0.032 ha of nursery, followed by foliar spray of neem seed kernel extract at 5% in the main field. Rice
tungro disease incidence was also less in this treatment, with maximum grain yield of 3580 kg/ha in ‘Kharif’ (July-Oct.) and
3257 kg/ha in ‘Rabi’ (Nov.-March) seasons, and a cost:benefit ratio of 1:3.9 in both seasons. However, the maximum cost:benefit
ratio of 1:5.6 and 1:5.8 in Kharif and Rabi seasons, respectively, was recorded withV. negundo. 相似文献
17.
18.
Von CH. Ulrichs und I. Mewis 《Anzeiger für Sch?dlingskunde》2000,73(2):37-40
The commercial available diatomaceous earth Fossil Shield® and the neem product Neem Azal-T/S® are tested as single treatments and in combination as controls for the stored product pests Sitophilus oryzae (L.) and Tribolium castaneum (Herbst). The diatomaceous earth, applied in concentrations of 0.5 g, 1 g and 2 g kg-1 rice, reduced numbers of surviving beetles significantly (over a period of 3 weeks). A single treatment with the neem product, in concentrations of 0.01 g, 0.1 g, 0.2 g and 1 g azadirachtin kg-1 rice, increased the mortality rate for both species significantly. The combination of neem and diatomaceous earth (1 g diatomaceous earth with 0.2 g or 1 g azadirachtin kg-1 rice) was more effective than the single treatment in reducing numbers of surviving beetles. 相似文献
19.
Domenico Rongai Claudio Cerato Luca Lazzeri 《European journal of plant pathology / European Foundation for Plant Pathology》2009,124(4):613-619
This study examines the effects of a vegetable fungicide on sugar beet powdery mildew (Erysiphe betae) and cucumber powdery mildew (Erysiphe cichoracearum). The formulations consisting of a dispersion of Brassicaceae meal in vegetable or mineral oils on infected leaves of sugar beet, reared in the greenhouse, and of musk melons cultivated
under plastic tunnels, were tested in comparison to each oil taken separately. Both formulations containing Brassicaceae meals, caused 94% of conidia to be distorted while for the untreated group only 2% were distorted. Furthermore, the leaf
area infected by E. betae was 56% for untreated plants and 2.7 and 9.9% respectively, for plants treated with meal containing mineral and vegetable
oil. Vegetable oil considered separately or with Brassicaceae meals showed no phytotoxicity, while the formulations based on mineral oil showed a significantly lower fresh and dry weight
on tomato plants. The low level or absence of phytotoxicity of plants treated with vegetable oil formulations suggests that
to improve the efficacy of powdery mildew control, they could be used mixed with sulphur. The efficiency of the vegetable
formulations in the powdery mildew control observed during these trials encourages further investigation on other parasitic
fungi and foliar pathogens. 相似文献
20.
The commercial available diatomaceous earth Fossil Shield® and the neem product Neem Azal-T/S® are tested as single treatments and in combination as controls for the stored product pests Sitophilus oryzae (L.) and Tribolium castaneum (Herbst). The diatomaceous earth, applied in concentrations of 0.5 g, 1 g and 2 g kg-1 rice, reduced numbers of surviving beetles significantly (over a period of 3 weeks). A single treatment with the neem product, in concentrations of 0.01 g, 0.1 g, 0.2 g and 1 g azadirachtin kg-1 rice, increased the mortality rate for both species significantly. The combination of neem and diatomaceous earth (1 g diatomaceous earth with 0.2 g or 1 g azadirachtin kg-1 rice) was more effective than the single treatment in reducing numbers of surviving beetles. 相似文献