Showing papers on "Azadirachta published in 2001"
TL;DR: Azadirachtin showed promissing for the control of the species not only for causing mortality but also for disrupting the development and for causing deformities involved in vital activities like feeding, walking or flying, making the insect vulnerable to several sorts of mortality agents or prevent them from causing damage to the crop.
Abstract: Azadirachtin is the most effective compound of the neem tree, Azadirachta indica A. Juss, with insecticidal and growth disruption properties on several species of insects. Its effects on the development and survival of Spodoptora littoralis (Boisduval) were studied under laboratory conditions. Third-instar larvae were individually fed on artificial diet treated with azadirachtin (from 0.01 ppm to 1 ppm wt/v), for two days, and transferred to plain diet. Survival, duration of stages and deformities were recorded daily. In a second experiment, the effects of azadirachtin on 3rd instar larvae and on last instar larvae were compared, by feeding the larvae with treated diet (0.3 ppm, 0.6 ppm and a control group), during the same period. A two-day feeding period promoted prolongation of the larval instars, reduction in the Mean Relative Growth Rate (MRGR), moulting disruption, morphological anomalies and mortality of S. littoralis in a dose-dependent manner. When higher concentrations were applied, the effects appeared shortly after treatment and mortality was higher. Many insects died after remaining inactive for several days or during prolonged moulting. At lower concentrations, if moulting was achieved, growth disruption and abnormalities were then likely to occur at the next moulting cycles. When azadirachtin was fed to last-instar larvae, larva-pupa intermediates were formed and the mortality was higher then for 3rd-instar larvae. Azadirachtin showed promissing for the control of the species not only for causing mortality but also for disrupting the development and for causing deformities involved in vital activities like feeding, walking or flying, making the insect vulnerable to several sorts of mortality agents or prevent them from causing damage to the crop.
139 citations
01 Jan 2001
TL;DR: Azadirachtin is the most effective compound of the neem tree, Azadirachta indica A. Juss, with insecticidal and growth disruption properties on several species of insects as discussed by the authors.
Abstract: Azadirachtin is the most effective compound of the neem tree, Azadirachta indica A. Juss, with insecticidal and growth disruption properties on several species of insects. Its effects on the development and survival of Spodoptora littoralis (Boisduval) were studied under laboratory conditions. Third-instar larvae were individually fed on artificial diet treated with azadirachtin (from 0.01 ppm to 1 ppm wt/v), for two days, and transferred to plain diet. Survival, duration of stages and deformities were recorded daily. In a second experiment, the effects of azadirachtin on 3 rd instar larvae and on last instar larvae were compared, by feeding the larvae with treated diet (0.3 ppm, 0.6 ppm and a control group), during the same period. A two-day feeding period promoted prolongation of the larval instars, reduction in the Mean Relative Growth Rate (MRGR), moulting disruption, morphological anomalies and mortality of S. littoralis in a dose-dependent manner. When higher concentrations were applied, the effects appeared shortly after treatment and mortality was higher. Many insects died after remaining inactive for several days or during prolonged moulting. At lower concentrations, if moulting was achieved, growth disruption and abnormalities were then likely to occur at the next moulting cycles. When azadirachtin was fed to last-instar larvae, larva-pupa intermediates were formed and the mortality was higher then for 3 rd -instar larvae. Azadirachtin showed promissing for the control of the
136 citations
Journal Article•
TL;DR: The antibacterial activity of Karanj and Neem seed oil in vitro against fourteen strains of pathogenic bacteria was assessed and it was observed that most of the pathogens were killed more rapidly at 4 degrees C than 37 degrees C.
Abstract: The antibacterial activity of Karanj (Pongamia pinnata) and Neem (Azadirachta indica) seed oil in vitro against fourteen strains of pathogenic bacteria was assessed. Using the tube dilution technique, it was observed that 57.14 and 21.42% of the pathogens were inhibited at 500 microl/ml; 14.28 and 71.42% at 125 microl/ml; and 28.57 and 7.14% at 250 microl/ml of Karanj and Neem oils, respectively. The activity with both the oils was bactericidal and independent of temperature and energy. Most of the pathogens were killed more rapidly at 4 degrees C than 37 degrees C. The activity was mainly due to the inhibition of cell-membrane synthesis in the bacteria.
93 citations
TL;DR: The results emphasize the importance of microbial inoculations for the production of robust, rapidly growing seedlings in nurseries and illustrate the advantage of inoculating soils of a low microbial population with indigenous microbes.
Abstract: Neem (Azadirachta indica A. Juss) seedlings were inoculated with arbuscular mycorrhizal (AM) fungi, Glomus intraradices Schenck and Smith and G. geosporum (Nicol. and Gerd.) Walker, Azospirillum brasilense, and phosphate-solubilizing bacteria (PSB) individually or in various combinations in unsterile soil under nursery conditions. Seedlings were harvested at 60 and 120 days after transplantation. Microbial inoculation resulted in increased mycorrhizal colonization, greater plant height, leaf area and number, root collar diameter, biomass, phosphorus, nitrogen and potassium content, and seedling quality. Inoculated seedlings also had low root/shoot ratios and low nutrient utilization efficiencies. Populations of PSB declined with seedling growth; contrarily populations of A. brasilense increased. A. brasilense and PSB populations were related to each other and influenced root colonization by AM fungi. Microbial inoculation effects were greatest when seedlings were inoculated with a combination of microbes rather than individually. This clearly indicates that these microorganisms act synergistically when inoculated simultaneously, with maximum response being when both AM fungi were coinoculated with A. brasilense and PSB. The results emphasize the importance of microbial inoculations for the production of robust, rapidly growing seedlings in nurseries and illustrate the advantage of inoculating soils of a low microbial population with indigenous microbes.
89 citations
TL;DR: It is demonstrated that neem seed extracts have potential for controlling both microbial and insect pests and antimicrobial activity with notable effects on some fungal phytopathogens.
Abstract: The antimicrobial effects of extracts of neem seed (Azadirachta indica A. Juss.) were investigated using microbial growth inhibition assays. A laboratory-prepared neem seed extract along with a commercially available formulated product, were characterized using HPLC, and shown to be effective against a range of bacteria in an agar diffusion assay. The active ingredient,i.e., the unformulated seed extract of the commercial product, also showed activity and this was further investigated in a biochromatogram, using the sensitive bacteriumBacillus mycoides. Results showed antibacterial activity as three discrete inhibition zones that did not correspond to the Rf of the major neem metabolites, azadirachtin, nimbin and salannin. This suggests that these compounds were not antibacterial. The colony radial growth rates of the fungal pathogens that cause ‘take-all’ and ‘snow mould’ disease were both significantly affected when the commercial, unformulated, neem seed extract was incorporated into the growth medium. Experiments in liquid culture suggested that the effect was fungistatic. Conidial germination of the commercially important obligate pathogenSphaerotheca fuliginea (powdery mildew) was reduced to 11%. The results show that neem seed extracts possess antimicrobial activity with notable effects on some fungal phytopathogens. This Work demonstrates that neem seed extracts have potential for controlling both microbial and insect pests.
71 citations
TL;DR: The in vitro fungitoxic effect of three biofertilizers used in organic agriculture and the neem oil on the entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana showed to be less toxic for the two fungi.
Abstract: The in vitro fungitoxic effect of three biofertilizers, E.M.-4, Multibion O and Supermagro used in organic agriculture and the neem oil (Azadirachta indica A. Juss) on the entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana was studied. These products were mixed in a medium where the two fungi were inoculated, and germination, vegetative growth and conidiogenesis were assessed. The biofertilizers Supermagro and E.M.- 4 showed to be less toxic for the two fungi whereas MultibionO caused major inhibition on M. anisopliae, with reductions in germination (-37.74%), colony diameter (-30.26%) and conidiogenesis (-42.62%). Neem oil promoted a larger negative effect on B. bassiana, inhibiting germination (-45.27%), colony diameter (-36.62%) and conidiogenesis (-84.93%).
71 citations
Journal Article•
TL;DR: The initial data appears to prove the antibacterial effect of Neem mouthwash against salivary levels of streptococcus mutans and lactobacillus, but longer term clinical trials are essential.
Abstract: Neem is one of the most widely researched tropical tree, with almost all it's parts being put for a variety of uses In the present study, the antibacterial effect of Neem mouthwash against salivary levels of streptococcus mutans and lactobacillus has been tested over a period of 2 months Also it's effect in reversing incipient carious lesions was assessed While streptococcus mutans was inhibited by Neem mouthwashes, with or without alcohol as well as chlorhexidine, lactobacillus growth was inhibited by chlorhexidine alone The initial data appears to prove it's effect in inhibiting S mutans and reversing incipient carious lesions, longer term clinical trials are essential
64 citations
TL;DR: Extracts of Cymbopogon citratus, Azadirachta indica (Neem) and Ocimum gratissimum were effective in controlling the growth of Rhizopus oryzae in vitro and in vivo.
Abstract: Extracts of Cymbopogon citratus, Azadirachta indica (Neem) and Ocimum gratissimum were effective in controlling the growth of Rhizopus oryzae in vitro and in vivo. Neem was found to be the best followed by C. citratus and O. gratissimum. Alcohol extracts of these plant species were more effective than water extracts in reducing the growth of the pathogen in culture and in checking rot development in potato tuber by the fungus. A. indica and C. citratus have considerable disease control potential and their extracts can be exploited as a source of pesticide of plant origin to control the soft rot in stored potato incited by Rhizopus oryzae.
58 citations
TL;DR: The results showed that the MAE technique can enhance the extraction of AZRL from different parts of neem possessing microstructures and that the solvent used not only influences the efficiency but also affects the selectivity of theMAE.
Abstract: The use of the microwave-assisted process (MAP) for the extraction of azadirachtin-related limonoids (AZRL) from various parts of the neem tree was investigated under different operating conditions. The influence of microwave power, solvent, and irradiation time on the recovery of AZRL was studied. The efficiency of the microwave-assisted extraction (MAE) of the seed kernel, the seed shell, the leaf, and the leaf stem was compared to that of conventional extraction methods. The content of AZRL in the extracts was estimated with a vanillin-based colorimetric assay and a multivariate calibration technique. The results showed that the MAE technique can enhance the extraction of AZRL from different parts of neem possessing microstructures. Investigation of the influence of the solvent also indicted that the solvent used not only influences the efficiency but also affects the selectivity of the MAE.
48 citations
TL;DR: No compounds tested proved as effective as malachite green, but some low-toxicity natural compounds and particular surfactants showed potential for further studies.
Abstract: Forty-nine compounds were tested in vitro for fungicidal activity against hyphae of the fish-pathogenic Oomycete fungus, Aphanomyces invadans. These comprised: (a) chemicals with previous reported activity against Oomycete fungi; (b) chemicals in use in Asia to treat ulcerative disease outbreaks; (c) commercial biocides and fungicides; (d) natural products with potential antimicrobial activity; and (e) surfactants tested separately and in combination with some of the above treatments. No compounds tested proved as effective as malachite green, but some low-toxicity natural compounds and particular surfactants showed potential for further studies. Some compounds that are currently in use in Asian aquaculture were shown to have no effect on A. invadans hyphae at recommended treatment rates. A range of compounds that demonstrated activity against the mycelium were selected for further testing in a zoospore motility assay. Lower treatment concentrations were required to inhibit zoospore motility than were required to inhibit hyphal growth. Zoospore activity ceased within 1 h of exposure to 2.5 parts per million (p.p.m.) coconut diethanol- amide; 1.25 p.p.m. propolis + 0.5 p.p.m. 13/6.5; 5 p.p.m. neem (Azadirachta siamensis) seed extract + 0.01 p.p.m. OP10; 20 p.p.m. tea tree (Melaleuca alternifloria) oil; and 25 p.p.m. D-limonene + 0.05 p.p.m. E-Z-MulseTM. The treated spores were shown to be non-viable in culture medium. Selected compounds were further tested for ability to inhibit zoospore production by A. invadans mycelium over a 72-h period. In toxicity trials, silver barb, Barbodes gonionotus (Bleeker), exposed to 2.5 p.p.m. coconut diethanolamide; 2.5 p.p.m. OP10; 0.5 p.p.m. E-Z-MulseTM; 20 p.p.m. neem seed extract + 0.5 p.p.m. OP10; and 5 p.p.m. D-limonene + 0.5 p.p.m. E-Z-MulseTM suffered no mortalities and no obvious behavioural changes. Similarly, rainbow trout, Oncorhynchus mykiss (Walbaum), exposed to 25 p.p.m. propolis + 1 p.p.m. OP10; 10 p.p.m. neem seed extract + 0.01 p.p.m. 13/6.5; and 10 p.p.m. D-limonene + 0.01 p.p.m. OP10 suffered no mortalities and no obvious behavioural changes.
47 citations
TL;DR: It is shown how azadirachtin can be noxious to M. caliginosus, but the short persistence makes this active ingredient a promising solution in integrated pest management programmes, when a lapse of time is guaranteed between the treatment and the introduction of the predator.
Abstract: The side-effects of three neem formulations (Neem-Amin EC, Stardoor and B.P. 20/S) were tested on the mirid predator Macrolophus caliginosus Wagner in the laboratory. Direct toxicity tests on 1st instar nymphs exposed to fresh dry residues on glass plates at different doses demonstrated that all the products are harmful to the insects with LD 50 values much lower than the maximum recommended rate (1.217, 0.264, 1.083 mg a.i./l instead of 15, 31.5 and 80 mg a.i./l for Neem-Amin EC, Stardoor and B.P. 20/S, respectively). Moreover a reduction of fecundity of the surviving females was assessed with Neem-Amin EC and B.P. 20/S. Persistence tests were carried out on sharp pepper plants treated at the maximum recommended rate. High mortality was recorded when the insects were introduced onto the plants just after the treatment, but no significant differences compared with the controls were observed 5 days after the treatment and any consequence on the fecundity of surviving females was detected. Our experiments showed how azadirachtin can be noxious to M. caliginosus, but the short persistence makes this active ingredient a promising solution in integrated pest management programmes, when a lapse of time is guaranteed between the treatment and the introduction of the predator.
TL;DR: The effect of nutrient amendment on growth of nine indigenous tree species planted on coal mine spoil was studied and log-transformed height-diameter relationships were significant for all tree species and treatments.
01 Jan 2001
TL;DR: This review includes relevant aspects of semiochemical substances derived from the secondary metabolism of plants and their possibilities real or potential for use in integrated pest management programmes.
Abstract: Management of insect pests with semiochemical substances originating from plants. The problems caused by the excessive use of synthetic insecticides mean that new management alternatives for insect pests should be looked for. One of these alternatives is the use of semiochemical substances derived from the secondary metabolism of plants, that have the capacity to intervene in chemical communication between organisms. The control of insects with various plants, such as neem (Azadirachta indica, Meliaceae), has increased the interest in utilizing these secondary metabolites. This review includes relevant aspects of these substances and their possibilities real or potential for use in integrated pest management programmes. The contribution of the plant chemistry of five plants utilized since long ago for the control of pests and that are currently produced on a commercial scale is briefly discussed: neem, piretro (Tanacetum spp., Asteraceae), Derris (Derris sp., Fabaceae), Lonchocarpus sp. (Fabaceae) and tobacco (Nicotiana tabacum, Solanaceae).
TL;DR: Azadirachta indica treatment for 48 days in albino rats resulted in a decrease in the total sperm count, sperm motility, and forward velocity, and the percentage of abnormal sperm increased and the fructose content of caudal semen of the epididymis decreased.
Abstract: Azadirachta indica treatment for 48 days In albino rats resulted in a decrease in the total sperm count, sperm motility, and forward velocity. The percentage of abnormal sperm increased and the fructose content of caudal semen of the epididymis decreased. The observations suggest that these effects are probably due to an androgen deficiency, caused by the anti-androgenic property of the leaves of A. indica, thereby affecting the physiological maturation of sperm.
Journal Article•
TL;DR: Though all the oils exhibited varied antifungal activities, oils of Azadirachta indica, Pongamia pinnata and Sesamum indicum showed maximum inhibitory activities.
Abstract: Trichophyton rubrum and Trichophyton mentagrophytes were Isolated from the patients with dermatophytosis and identified. Minimum Inhibitory concentration and minimum fungicidal concentrations of 7 edible and nonedible (unrefined) oils were tested against T. rubrum and T. mentagrophytes. Though all the oils exhibited varied antifungal activities, oils of Azadirachta indica, Pongamia pinnata and Sesamum indicum showed maximum inhibitory activities.
TL;DR: The results suggest that neem seedlings adjust their nutrient use efficiency and can be grown even under limited available resources, and it is inferred that the species can tolerate soil resource depletion caused by competitor species.
Abstract: Production of quality seedlings is an important aspect of successful tree planting. No information is available on the effect of nutrients and water on the growth and development of the seedlings of neem (Azadirachta indica A. Juss), an important component of many tropical agroforestry systems. In an experiment in central India, the growth and nutrient-use efficiency of neem seedlings grown at various levels of light, nutrients (N and P), and water stress were determined. Seedlings were given light (diffused and complete) and nutrient (N and P) treatments comprising either high N-high P, high N-low P, low N-high P, or low N-low P. Seedlings grown in complete light (800 μ mol/m2/s) had four times more biomass than those grown in diffused light (200 μ mol/m2/s). Significant increase in seedling biomass was observed with nitrogen application, while phosphorus had no effect on biomass. Leaves contributed maximum biomass, followed by roots and stem. Nutrient use efficiency decreased with an increase in the supply of nutrients. In another experiment, containerized and bare-root seedlings were subjected to five watering treatments, viz., watering twice a week, watering weekly, watering every alternate week, watering every third week, and natural precipitation. Plant moisture stress affected both growth and survival of neem seedlings. Only 50 per cent of seedlings survived in severe drought treatment (no. 4) whereas 90 to 95 per cent seedlings showed growth in all other treatments. Plant moisture stress in severe drought treatment averaged −21 bar while in other treatments it ranged from −9 to −12 bar. Shoot-root ratio was high in bare-root seedlings as compared to containerized seedlings. Containerized seedlings had shown better endurance against drought than the bare-root seedlings. The results suggest that neem seedlings adjust their nutrient use efficiency and can be grown even under limited available resources. It is also inferred that the species can tolerate soil resource depletion caused by competitor species.
Journal Article•
TL;DR: In this paper, the effects of leaf extracts of 14 different non-host plant species on in vitro conidial germination of Phaeoisariopsis personata, the causal organism of late leaf spot (LLS) of groundnut were evaluated.
Abstract: The effects of leaf extracts of 14 different non-host plant species on in vitro conidial germination of Phaeoisariopsis personata, the causal organism of late leaf spot (LLS) of groundnut were evaluated. Aqueous and ethanol leaf extracts of Datura metel, Lawsonia inermis and aqueous leaf extracts of Sphaeranthus indicus at 25% (w / v) concentration completely inhibited the conidial germination of P. personata both at 24h and 48h after incubation. Aqueous leaf extracts of Blumea bifoliata, Eucalyptus globules, Ocimum sanctum and Pongamia pinnata, and ethanol leaf extracts of Azadirachta indica and S. indicus inhibited the conidial germination by> 90%. Aqueous and ethanol leaf extracts of L inermis and S. indicus wrer highly inhibitory to conidial germination up to 1% concentration. Aqueous and ethanol leaf extracts of D. metel and ethanol leaf extract of A. indica were highly inhibitory to P. personata even at 0.01% (100 ppm) concentration. Ethanol leaf extract of A. indica up to 80 ℃, aqueous leaf extracts of D. metel and S. indicus up to 100 ℃, and L. inermis up to 60 ℃, were highly stable and retained their fungitoxic effects. Extract of D. metel was antifungal even after 180 days when it was stored both at room temperature and 4 ℃. Aqueous leaf extract of D. metel at 2% concentration effectively reduced the development of LLS by> 60%, under greenhouse conditions both in prophylactic and simultaneous applications. Extracts of D. metel could be a potential economical and an eco-frendly alternative for control of late leaf spot, and its efficacy under field conditions is further being evaluated.
TL;DR: A several‐fold improvement was observed in plant‐growth parameters such as plant weight, percent pollen fertility, pod numbers, chlorophyll content, nitrate reducíase activity in leaves and root‐nodulation and the population of plant‐parasitic nematodes and frequency of soil‐inhabiting fungi also influenced by the depth of ploughing.
Abstract: The oil‐seed cakes of neem (Azadirachta indica), castor (Ricinus communis), linseed (Linum usitatissimum), groundnut (Arachis hypogaea), mustard (Brassica campestris) and duan (Eruca sativa) were tested for their efficacious nature against plant‐parasitic nematodes and soil‐inhabiting fungi infesting lentil and also on the subsequent crop, mungbean in field trials. The population of plant‐parasitic nematodes such as Meloidogyne incognita, Rotylenchulus reniformis, Tylenchorhynchus brassicae, Helicoty‐lenchus indicus etc., and the frequency of pathogenic fungi Macrophomina phaseolina, Fusarium oxysporum f. lentis, Rhizoctonia solarii, Septoria leguminum, Sclerotium rolfsii, etc., were significantly reduced by the incorporation of oil‐seed cakes, however, the frequency of saprophytic fungi Aspergillus niger, Trichoderma viridae, Penicillium degetatum, etc., was increased. A several‐fold improvement was observed in plant‐growth parameters such as plant weight, percent pollen fertility, pod numbers, chlorophy...
Journal Article•
TL;DR: The oral administration of a soxhlated crude ethanolic extract of leaves of neem to adult male mice for 6 weeks reduced the sperm count and increased the frequency of spermatozoa with abnormal head morphology and it is suggested that at least one of the constituents of the extract may have interfered with the DNA.
Abstract: The oral administration of a soxhlated crude ethanolic extract of leaves of neem (Azadirachta indica Ajuss; family Meliaceae) to adult male mice for 6 weeks (one spermatogenic duration) at the rate of 0.5, 1.0 or 2.0 g/kg body weight per day increased the incidences of structural changes and synaptic-disturbances in meiotic chromosomes and also caused more disruptions of meiosis. The extract reduced the sperm count and increased the frequency of spermatozoa with abnormal head morphology. It is suggested that at least one of the constituents of the extract may have interfered with the DNA. The result was chromosome strand breakages, or spindle disturbances, and the regulation of genes responsible for sperm shaping was affected.
01 Jan 2001
TL;DR: Results suggest that neem extracts at concentrations higher than 2.5% are promising for M. tanajoa control, and clove extract at 5.0% did not cause any significant mortality of larvae and nymphs.
Abstract: The effect of aqueous extracts of neem (Azadirachta indica A. Juss), clove (Syzigium aromaticum L.) and chinaberry (Melia azedarach L.) on survival of eggs, larvae, nymphs and adults females of the cassava green mite, Mononychellus tanajoa (Bondar), was studied. Egg treatment consisted of dipping cassava leaf discs with 30 eggs into each plant extract concentration. Leaf discs dipped into destilled water were used as control. The treated and control leaf discs were dried for 30 minutes under environmental conditions. The effect of the several plant extracts on immature stages and females was studied by exposing 40 individuals to each plant extract concentration. Neem extract at concentrations 0.5, 2.5 and 5% w/v caused mortality of 16.8, 59.2 and 60% of the eggs, while the clove 5% w/v and the control treatment caused mortality of 10.8 and 4.2%, respectively. Larvae, protonymphs and deutonymphs treated with neem extracts at 2.5 and 5% had mortality ranging from 57.5 to 100% and from 85 to 100%, respectively, but they were not killed by neem extract at 0.5%. Clove extract at 5.0% did not cause any significant mortality of larvae and nymphs. Neem extracts at 2.5 and 5% caused 97.5 and 100% mortality of M. tanajoa females, while, at the same concentrations, chinaberry extracts caused only 5 and 7.5% mortality and clove extracts caused 5 and 12.5% mortality of females, respectively. These results suggest that neem extracts at concentrations higher than 2.5% are promising for M. tanajoa control.
Journal Article•
TL;DR: A field experiment was conducted during 1995-96 at New Delhi, to study the efficiency of modified forms of urea materials, viz. prilled urea (PU), neem cake-coated urea, NCU, 0.5% of 10% neem oil emulsion-covered urea and 0. 5% of 20% NEEM-EMELO-COATED urea at varying N rates (0, 60 and 120 kg/ha).
Abstract: A field experiment was conducted during 1995–96 at New Delhi, to study the efficiency of modified forms of urea materials, viz. prilled urea (PU), neem cake-coated urea (NCU), 0.5% of 10% neem oil emulsion-coated urea and 0.5% of 20% neem oil emulsion-coated urea at varying N rates (0, 60 and 120 kg/ha) on the productivity of lowland transplanted rice [Oryza sativa L.). Each incremental N level recorded significantly higher growth parameters, yield attributes, grain and straw yields and also N uptake over its preceding level. However, apparent N recovery decreased with increasing N levels. Neem cake-coated urea and neem oil emulsion-coated urea irrespective of the concentration improved rice growth, yield attributes and resulted in more grain and straw yields, N uptake and also higher apparent N recovery than did commercial prilled urea.
TL;DR: The binary and tertiary combinations of plant-derived molluscicides Azadirachta indica and Cedrus deodara oil with synergists MGK-264, piperonyl butoxide and fruit powder of Embelia ribes were used against the Lymnaea acuminata and it was observed that the toxic effects of these mixtures were time- and dose-dependent.
TL;DR: Although the extracts used did not affect the incubation period, neem extract significantly reduced egg viability at 1% probability, and the duration of the deutochrysalis and teleiochrysalis stages was slightly but significantly longer for neem at 1.0% probability.
Abstract: The use of plant extracts is a promising alternative for the control of phytophagous mites. This study was carried out to test the bio-activity of neem, Azadirachta indica A. Juss. and clove, Syzigium aromaticum L., aqueous extracts on the behaviour of the cassava green mite, Mononychellus tanajoa (Bondar). Recently hatched larvae were individualized onto cassava leaf discs previously immersed in different concentrations of the extract and in distilled water, and maintained at these conditions until reaching maturity. The females were individualized onto untreated leaf discs right after emergency and mated with males from the rearing stock. The evaluations were taken each 12 h. The two highest neem concentrations (1.0 and 0.75g of ground neem seeds 100 mL-1 water) gave the best results, causing 72.5 and 37.5% of larval mortality, respectively. Mortality of other stages was up 16%. The mortality of the combined immature stages was 84.6 and 55%, at neem concentrations of 1.0 and 0.75%, respectively. The duration of the deutochrysalis and teleiochrysalis stages was slightly but significantly longer for neem at 1.0% probability. The plant extracts did not affect female fecundity, which ranged from 6.5 to 8.6 eggs/female/day. Although the extracts used did not affect the incubation period, neem extract significantly reduced egg viability at 1% probability.
TL;DR: An enzyme-linked immunosorbent assay (ELISA) was developed for azadirachtin (aza), a biopesticide from the neem tree (Azadirachta indica A. Juss), and may be applied to environmental monitoring of aza and quality assurance studies of aze-based commercial formulations.
Abstract: An enzyme-linked immunosorbent assay (ELISA) was developed for azadirachtin (aza), a biopesticide from the neem tree (Azadirachta indica A. Juss). The immunogen was synthesized by epoxidation using the furan ring in the aza molecule. Rabbits were immunized with either bovine serum albumin (BSA)-azadirachtin or ovalbumin (OA)-azadirachtin conjugate. Evaluation of the antisera by antibody capture assay showed that the antibody titer of antisera raised against OA-aza was 1:30,000. An indirect competitive ELISA was developed with BSA-azadirachtin as coating antigen and aza-specific antibodies raised against OA-aza immunogen. The immunoassay showed an inhibitory concentration (IC50) value of 75 ppb, with a range of detection from 0.5 to 1,000 ppb for azadirachtin [based on regression analysis, y= 85.87 (-18.89x); r2 = -0.97]. Cross-reactivity of the antibodies with 2 aza- derivatives (22,23-dihydro-23beta-methoxy azadirachtin and 3-tigloylazadirachtol) was 33 and 29%, respectively. The indirect competitive ELISA was validated and evaluated by quantitating aza in spiked agricultural commodities and from neem formulations. Azadirachtin was spiked into 5 different agricultural commodities: tomato, brinjal, coffee, tea, and cotton seed at 500 and 1,000 ppb and recovered at 62-100%. In samples drawn from 6 lots, the aza content in neem-seed kernels ranged from 0.1 to 0.15%; in commercial neem formulations the content ranged from 200 to 2,000 ppm. The method developed may be applied to environmental monitoring of aza and quality assurance studies of aza-based commercial formulations.
Journal Article•
TL;DR: Azadirachtin and turmeric oil, the major constituents of Azadirachta Indica (neem), and Curcuma longa (turmeric) exhibited significant insect growth inhibition and antifeedant activity against Spilosoma obliqua larvae.
Abstract: Azadirachtin and turmeric oil, the major constituents of Azadirachta Indica (neem), and Curcuma longa (turmeric) exhibited significant insect growth inhibition and antifeedant activity against Spilosoma obliqua larvae. The activity of azadirachtin was considerably enhanced following incorporation of different concentrations of turmeric oil in the mixtures. Among the three different proportions (1:1, 2:1, 3:1), azadirachtin-turmeric oil (1:1) mixture recorded pronounced IGR activity (EC50, 1.26 x 10−2/2.16 x 10−2 %) and considerable antifeedant activity (EC50 2.90 x 10−2/1.0 x 10−2 %) against third/fifth instar larvae. The apparent enhancement in activity of azadirachtin-turmeric oil mixture was attributed to the possible additive, synergistic and/or stabilizing effect of turmeric oil.
TL;DR: Aqueous neem seed kernels extracts (NSKE) were used to treat flea-infested goats in Morogoro, Tanzania to determine their efficacy for flea control as discussed by the authors.
Abstract: Aqueous neem seed kernels extracts (NSKE) were used to treat flea-infested goats in Morogoro, Tanzania to determine their efficacy for flea control. Mean population densities of the insects were significantly lower in the treated goats compared to their untreated counterparts (P < 0.05). It was concluded that NSKE has potential in controlling livestock fleas, but further studies are needed to determine the active principals against fleas and their mode of action.
Journal Article•
TL;DR: A evaluation was conducted on eight botanicals for their insecticidal property against-pests of kagzilime (Cirus aurantifolia S.), Spray of neen Phyllocnistis cirella St and psylla (Diaphorina citri K).
Abstract: A evaluation was conducted during 1997-99 at Anand on eight botanicals, viz mint (Mentha piperita L.), tulsi (Ocimum sanctum L.), ardusi (Adhatoda vasica L.), Karen (Nerium indicum M.), naffatia (Ipomoea fistulosa Mart), neem (Azadirachta indica A. Juss.), arni (Cierodendrum Bur.) and boufainvillea (Bougainvillea spp.) were evaluated for their insecticidal property against-pests of kagzilime (Cirus aurantifolia S.), Spray of neen Phyllocnistis cirella St and psylla (Diaphorina citri K).
TL;DR: In this paper, the methanolic extract of Azadirachta indica leaves was used to identify three triterpenoids of biogenetic interest, namely, melianol, desfurano-desacetylnimbin-17-one and meliatetraone.
01 Jan 2001
TL;DR: The results concluded that the leaf extract of Prosophis juliflora can be used as an alternative to conventional chemical fungicide though its effect was next only to carbendazim which was included in the present study as a check.
Abstract: Rice blast caused by Pyricularia grisea Cav continues to be a major constraint for rice production. Since the existing chemical control measures being costly and may favour development of resistant strains of the pathogen, potential alternative methods have been explored in the present studies. Leaf extracts from 20 plant species were evaluated at 10 % concentration under laboratory conditions. In vitro studies indicated that the plant extracts of Prosopis juliflora followed by Zizyphus jujuba, Azadirachta indica, Abutilon indicum, Cynodon dactylon exhibited maximum antifungal activities towards inhibiting the mycelial growth as well as spore germination of the pathogen. The promising plant extracts were further evaluated for their efficacies in disease management under glass house and field conditions. The results concluded that the leaf extract of Prosophis juliflora can be used as an alternative to conventional chemical fungicide though its effect was next only to carbendazim which was included in the present study as a check. Further, biochemical analyses of leaf samples collected from pot culture studies showed that treatment with Prosophis juliflora caused enhanced activites of the defense enzymes viz. peroxidase, polyphenol oxidase and phenylalanine ammonia lyase which may account for their antifungal activities.