Showing papers on "Azadirachta published in 1995"

The neem tree Azadirachta indica A. Juss. and other meliaceous plants: sources of unique natural products for integrated pest management, medicine, industry and other purposes.

Abstract: The tree and its characteristics biologically active ingredients effects on viruses and organisms neem products for pest management and practical results of neem applications against arthropod pests, and probability of development of resistance toxicity of neem to vertebrates and side effects on beneficial and other non-target organisms various uses of neem products economic, socioeconomic and policy considerations, and neem in sociocultural life in South Asia other meliaceous plants containing ingredients for pest management and other purposes register of scientific and common names. (Part contents).

Toxicity of neem to natural enemies of aphids.

Abstract: Neem [Azadirachta indica (A. Juss.)] seed oil (NSO) applied in three concentrations, 0.5%, 1% and 2%, to potted plants infested with green peach aphid,Myzus persicae (Sulzer), totally prevented adult eclosion of larval coccinellids,Coccinella undecimpunctata L., and reduced adult eclosion of syrphids,Eupeodes fumipennis (Thompson), to 11%, 7% and 0%, respectively, of the controls. Under the same conditions, NSO did not reduce the rate of parasitism ofM. persicae byDiaeretiella rapae (Mcintosh), but emergence of parasitoid adults from aphid mummies collected from treated plants was reduced to 35%, 24% and 0%, respectively, of the controls. Although topical treatment of predator larvae with NSO at concentrations of up to 5% did not affect survival, emergence of parasitoids from mummies dipped in aqueous emulsions of NSO at similar rates was reduced significantly. Under field conditions, sprays of NSO and neem seed extract to plants had no significant impact on the number of aphids parasitized. Although total numbers of predators were reduced, numbers of predators relative to aphid numbers were similar to those in controls. Neem insecticides may be suitable for use in integrated pest management programs, as under field use they appear to be relatively benign to aphid predators and parasitoids.

Antimalarial activity in vitro of Cochlospermum tinctorium tubercle extracts

Abstract: Resistance of Plasmodium falciparum to current antimalarial compounds has drastically increased during the last few years and is now a major public health problem. We have studied plants traditionally used in Africa against malaria. Extracts of the tubercles of Cochlospermum tinctorium A. Rich, commonly used in Burkina Faso, were tested in vitro on 2 strains of P. falciparum, one (FcB1-Colombia) chloroquine resistant and the other (F32-Tanzania) chloroquine sensitive. Extracts were obtained by infusion and decoction. The 50% inhibitory concentrations (IC50) were determined by measuring [3H]hypoxanthine incorporation and also by microscopical examination which permitted the determination of parasite stages. We obtained similar results with fresh extracts, frozen extracts, and lyophilized extracts of C. tinctorum. IC50 values were of the order of 1–2 μg/mL, about one-tenth of those reported for extracts of neem leaves (Azadirachta indica) and about half the values reported for Artemisia annua extracts.

Evaluation of neem Azadirachta indica seed extracts and oils as oviposition deterrents to noctuid moths

Abstract: Applications of three concentrations of oil-free neem seed extracts (Azadirachta indica A. Juss; Meliaceae) to cabbage plants in cages did not deter oviposition by individuals of three species of noctuid moths, Trichoplusia ni, Peridroma saucia, and Spodoptera litura. The concentrations used corresponded to 10, 50, and 100 ppm of the main active ingredient, azadirachtin. The total number of eggs laid per female, female longevity, and median day of oviposition were not affected. Sprays of the neem oil-based insecticide Margosan-O R , and a 1% aqueous emulsion of a refined neem seed oil similarly had no effect on any of the parameters studied. However, a 1% crude oil emulsion significantly reduced the proportion of eggs laid by S. litura on treated plants. Our results suggest that literature reports of significant neem-based oviposition deterrence to S. litura are the result of compounds that are removed by higher levels of processing and thus not likely to be found in most commercial neem seed formulations. Sprays consisting of highly processed neem seed extracts, used at concentrations that provide larval control, are unlikely to be generally effective as oviposition deterrents to noctuid pests.

Use of neem oil as a mosquito repellent in tribal villages of mandla district, madhya pradesh.

Abstract: A field study was carried out to evaluate the mosquito repellent action of neem (Azadirachta indica) oil in tribal forested villages of District Mandla. Various concentrations of neem oil mixed in coconut oil (1-4%) were applied to the exposed body parts of human volunteers. Results revealed 81-91% protection during 12 h period of observation from the bites of anopheline mosquitoes. Neem oil is an indigenous product and a practical solution to curtail mosquito nuisance.

Changes in epididymal structure and function of albino rat treated with Azadirachta indica leaves.

Abstract: The histological and biochemical changes in the caput and cauda epididymis of albino rat treated with 20, 40 and 60 mg dry powder of the leaves of A. indica per day for 24 days are reported. In the treated rats, the height of the epithelium and the diameter of the nucleus in both the regions were reduced. The lumen of the caput was packed with lymphocytes. Biochemically, a decrease in the protein content and acid phosphatase activity and an increase in the alkaline phosphatase and lactate dehydrogenase activities were observed in both the regions. The effect was dose dependent. Further, serum testosterone concentration in the higher dose treated animals decreased significantly. The results suggest a possible antiandrogenic property of the leaves of A. indica.

Development of combined use of neem (Azadirachta indica) and water management for the control of culicine mosquitoes in rice fields.

Abstract: . Crude neem products have earlier shown considerable promise for control of culicine mosquito vectors in rice fields as a by-product of their agricultural use as fertilizers, but suffer from disadvantages of bulkiness and lack of stability in storage. Relatively stable lipid-rich fractions of neem were shown to be as effective as good-quality crude neem products in control of breeding of culicine vectors of Japanese encephalitis, and also produced a slight but significant reduction in populations of anopheline pupae. Neem-based formulations coated over urea significantly increased grain yield, but used alone did not, whereas combining the use of neem-coated urea and water management by intermittent irrigation had a greater effect on grain yield than that of water management alone. The neem fractions were relatively cost-effective, and the combined water management and neem-coated urea strategy is acceptable to farmers, who are already aware of the benefits of the use of neem-coated urea, and of water management. This technology therefore has considerable promise as an environmentally benign method of rice-field mosquito control that could be sustainably implemented by farmers.

Variation of azadirachtin content during growth and storage of neem (Azadirachta indica) seeds

Abstract: Variation of azadirachtin content during the growth and storage of neem seeds has been studied by reversed-phase high-performance liquid chromatography using anisole as internal standard. Samples were collected every fortnight from the initial stage of buds to ripened fruit stage and analyzed using an efficient sample preparation protocol developed for this purpose. Results indicated that azadirachtin appears only after the 9th week, gradually reaches the maximum of 0.38 +/- 0.06% (w/w, on a dry weight basis) around the 17th week, and decreases to 0.29 +/- 0.03% (w/w) by the 19th week. Thus, the fruits can be profitably harvested in the 17th week of development (when the neem fruit turns from green to yellow) for better yield of azadirachtin. Application of the method for storage studies of neem seeds indicated that azadirachtin was unstable under normal conditions of storage of the seeds, with azadirachtin content reducing to about 68% of the original level in a period of 4 months in the dark and to 55% in daylight.

Mortality and predation efficiency of Coleomegilla maculata lengi Timb. (Col., Coccinellidae) following application of Neem extracts (Azadirachta indica A. Juss., Meliaceae)

Abstract: The toxicity of two neem (Azadirachta indica) extracts and of the chemical insecticide malathion was evaluated on adults of the predacious coccinellid C. maculata. Bioassays were carried out with both neem formulations at 1, 5, 10, 20 and 50% concentration. The azadirachtin quantities contained in neem oil (v/v) and neem seed kernels (w/v) were 13.7 ppm AZA and 91.0 ppm AZA respectively. Malathion was tested at field rate (2.85 g (AI)/L). The mortality rate was evaluated in the laboratory after topical applications on the ventral side of the coccinellids. Adult mortality rate after 72 h was 100% following malathion treatments. Only one dose of neem oil (10%) resulted in significantly greater mortality than in the control group. No toxicity was observed after the treatments with the aqueous suspension of ground neem seeds. Predation efficiency of C. maculata was also evaluated after topical application of these three insecticides at sublethal doses. Fifteen min after treatments, adult coccinellids were presented 30 aphids for 24 h. The aqueous suspension of ground neem seeds caused a 50% reduction in the number of aphids consumed.

Control of mosquito breeding using wood scrapings treated with neem oil.

Abstract: Wood scrapings were given shape of a ball and soaked in 5, 10 and 20% neem (Azadirachta indica) oil diluted in acetone. Control of Anopheles stephensi and Aedes aegypti breeding in water storage overhead tanks (OHTs) with the application of these balls was achieved for 45 days. Two balls soaked in 5% neem oil produced the best results among other concentrations tested.

Responses of seeds of Azadirachta indica (neem) to short-term storage under ambient or chilled conditions

Abstract: Neem seeds show curious post-shedding behaviour and have been variously documented as orthodox, intermediate or recalcitrant, apparently relating to provenance. In addition, even in the air-dry state, hermetically stored seeds rapidly lose viability. In the present case, putatively recalcitrant, hydrated neem seeds from a Kenyan coastal provenance were stored in loosely-closed polythene bags to ascertain : 1. Whether or not the axes showed metabolic enhancement indicative of the onset of germination under ambient storage conditions for 10 d ; and 2. Whether chilling (4 ± 2°C for 10 d) had an adverse effect on the axis cells. There was a slight germination lag relative to the control material in the ambient-stored seeds, which is ascribed to their partial enclosure, but the totality of germination was unaffected, while chilling had markedly adverse effects on both rate and totality. The ultrastructure of control material, sampled prior to storage, was typical of embryonic axes in the stage of late development or early stages of germination. During ambient storage, there was considerable enhancement of ultrastructural features indicating that germination (even though slightly delayed) was indeed underway. In contrast, a regression of subcellular development accompanied chilling, many axis cells showing degenerative changes. In terms of this behaviour, seeds of A. indica from this African provenance conform to the characteristics expected of tropical recalcitrant species.

Antinociceptive action of Azadirachta indica (neem) in mice: possible mechanisms involved.

Abstract: Azadirachta indica (AI, Neem) was tested for analgesic potency in experimental pain models in mice. In the glacial acetic acid (GAA) induced writhing test, AI (10, 30 and 100 mg/kg) dose-dependently reduced both the incidence and the number of writhes. Similarly, AI, at the dose levels tested, also enhanced tail withdrawal latencies in the tail-flick test for nociception. In the interaction studies, pretreatment with the opioid antagonist, naloxone (1 mg/kg) and the central noradrenaline depleter, DSP-4 (50 mg/kg) attenuated AI analgesia by differential degrees in both experimental models, whereas, the serotonin synthesis inhibitor, PCPA (300 mg/kg) potentiated the same. These results suggest that both central and peripheral mechanisms and complex neural pathways, opioid and non-opioid, may be involved in AI induced analgesia.

Susceptibility of neem to attack by the Formosan subterranean termite, Coptotermes formosanus Shir. (Isopt., Rhinotermitidae)

Abstract: The neem tree, Azadirachta indica, is a source of natural compounds with potent insecticidal, feeding deterrent and insect growth regulator activity. However, little information is available on the effects of these natural products on termites. We assessed the effects of mulches made from ground neem branches and roots on survival of the Formosan subterranean termite, Coptotermes formosanus, and compared termite feeding and survival on neem wood and bark to that on susceptible Pseudotsuga menziesii wood. Termite survival was fairly low in both P. menziesii heartwood and neem mulches over the 14 day test period, and did not differ significantly among those treatments. However, termites exposed to either P. menziesii wood, neem wood, or neem bark for 4 weeks fed significantly less on neem wood and bark. Feeding on neem bark caused significant termite mortality (56.4%) in comparison to that induced by feeding on neem wood (27.1%) or P. menziesii wood (12.5%). Thus, although neem is not entirely resistant to termite attack, the antifeedant properties of its wood and bark and the toxicity of neem bark support the use of neem trees for arboriculture in areas where termites are a problem.

Somatic embryogenesis in neem (Azadirachta indica)

Abstract: Azadirachta indica A. Juss is commonly known as Neem or “Margosa”, and also Indian Lilac (synonym Melia azadirachta L.; Melia indica A. Juss Brand or Melia parviftora Moon; family Meliaceae). It is a native to Burma and dry arid regions of the Indian subcontinent. During the last century, it was introduced into the arid zones of Africa and is now being widely planted in Australia, Fiji, Mauritius, Central and South America, The Caribbean, Puerto Rico, Haiti, Philippines and other countries.

Bioefficacy of Six Neem (Azadirachta indica) Products against Mosquito Larvae

Abstract: Bioassay tests were carried out to determine the efficacy of six neem products against early fourth instar larvae of Anopheles stephensi, a vector of malaria, Culex quinquefasciatus, vector of rilariasis and Aedes aegpti, vector ro fengue eever ri nndia. Neem products showed poor rarvicidal lctivity within 24 hr of exposure but some of these products showed good insect growth regulator (IGR) activity. Larvae of An. stephensi in general were most tusceptible while those of Aedes aegypti were reast stsceptible to different neem products. Among the various products tested, Neemark, was most effective against Anstephensi (EC50 = 0.0005%) while Neemark II was most effective against Culex quinquefasciatus (EC50 =0.0023%) and Aedes aegypti) (EC50 =0.0055%)

Molluscicidal activity of different combinations of the plant products used in the molluscicide Pestoban

Abstract: Pestoban is a mixture of three plant extracts, only two of which (Cedrus deodara and Azadirachta indica oils) show toxicity against each of the snail species under test. The third (Embelia ribes) is non-toxic, but when all three are mixed, the toxicity of the mixture is 103 time more active than either of the two toxic components.

Evaluating different plant extracts against three major diseases of mulberry

Abstract: The effects of 10% alcoholic water extracts of fresh plant parts from 20 different species were investigated on the development of powdery mildew (Phyllactinia corylea) leaf spot (Pseudocercospora mori) and leaf rust (Cerotelium fici) of mulberry during 1992-93 and 1993-94 in West Bengal, India The pooled data of these 2 years revealed that the extract of Adhatoda zeylanica was most effective in decreasing the severity of all the diseases followed by extracts of Azadirachta indica, Launaea coromandelica [Lannea coromandelica] and Oxalis corniculata which significantly minimized powdery mildew and leaf rust, while those of Celosia argentia and Chromolaena odorata reduced leaf spot and leaf rust Extracts from several other plant species exhibitedan ability to reduce either leaf rust or powdery mildew disease

Genotoxic Effects of Crude Extract of Neem(Azadirachta indica)in Bone Marrow Cells of Mice

Abstract: Oral administration for one week of 0.5, 1.0 or 2.0g/kg body weight/day of crude leaf extract of neem (Azadirachta indica) to laboratory inbred albino Swiss-mice induced both individual and gross types of mitotic chromosome abnormalities in the bone marrow cells. The frequency of total abnormalities was dose-dependent. Gross type abnormalities appeared even at the lowest dose and remained unchanged in their frequency at the higher doses; the individual type abnormalities were induced only at the highest dose.

Neem ( Azadirachta indica ) - Nature's Drugstore

Abstract: The Neem tree is one of the most important and valuable trees of India. The Non-Wood Products of Neem have multipurpose use in medicine, cosmetics and fertilizers. Neem oil and its derivatives are used in soap making and in Pharmaceutical Industry. Neem cake is good organic manure and is also used in the management of insect and pest. The present article is to highlight the uses of Non-Wood Products of neem in the daily life of majority of Indian population.

Azadirachtin-A content of seeds of Neem Ecotypes in relation to the Agroecological Regions of India

Abstract: The azadirachtin-A content of the seed kernels of the neem, Azadirachta indica A. Juss, ecotypes from 11 of the 21 agroecological regions of India has been investigated in relation to the agroecological-factors such as ecosystem and climate, growth period (the period of continuous plant growth in a year) arid soil. The azadirachtin -A content ranged from 0.14 -2.02% w/w of kernel with an average of 0.68%. The ecotypes growing in the regions with coastal, arid and semiarid ecosystems showed high (>0.72%) and those from the regions with subhumid ecosystem showed very low (0.27%) average azadirachtin -A contents. The growth period upto 150 d appeared to be more conducive for azadirachtin -A content under arid and semiarid ecosystems. The ecotypes growing in the agroecological regions with red soil had higher azadirachtin -A content as compared to those growing in other soil types; the highest azadirachtin -A content being recorded in the samples from red soil falling under the rain-shadow areas of south-west monsoon.

Efficacy of foliar extracts against pre- and post-harvest diseases of sponge-gourd fruits

Abstract: S.K. AHMAD AND J.S. PRASAD. 1995. The inhibitory potential of aqueous foliar extracts of Adhatoda vasica, Azadirachta indica, Catharanthes roseus, Datura fistulosa, Lantana camara, Muraya exotica, Ocimum sanctum, Ricinus communis and Strychnos nux-vomica were evaluated against soft rot diseases of sponge-gourd fruits caused by Helminthosporium spiciferum and Fusarium scirpi. Conidial germination of F. scirpi and H. spiciferum were reduced to about 75% when their spores were treated with A. indica, C. roseus, D. fistulosa, L. camara, M. exotica and O. sanctum. Considerable reductions (50%) in mycelial dry weights and colony diameters were recorded in liquid media containing (20%) aqueous extracts of C. roseus, D. fistulosa and M. exotica. Other extracts reduced the mycelial growth but to a lesser extent. Post-infection treatment of sponge-gourd fruits with the extracts of A. indica, L. camara, M. exotica, O. sanctum, D. fistulosa and C. roseus almost fully inhibited the spread of disease. Treatment of fruits with A. indica and C. roseus before fungal infection reduced the spread of disease caused by both the pathogens, whereas M. exotica, O. sanctum and D. fistulosa reduced the spread of soft-rot caused by F. scirpi but not by H. spiciferum.

Variation Studies in Provenances of Azadirachta Indica (the Neem Tree)

Abstract: An exploratory survey was undertaken and 10 provenances of neem were collected from Karnataka and Andhra Pradesh during June, 1993. Analysis of three characters i.e., seed length, width and seed weight revealed good amount of genetic variability for those characters studied. Ramanager 'H' provenance represent highest value of Range and lowest of C.V. for all three characters studied. The highest C.V. for seed length was recorded in Ramanager 'Y' provenance (73%), for seed width and seed weight, it was Hosakote provenance (35.7 and 25.1% respectively).

Shelf stable insect repellent, insect growth regulator and insecticidal formulations prepared from technical azadirachtin isolated from the kernel extract of Azadirachta indica

Abstract: Storage stable azadirachtin, an insect repellent and insect growth regulator, and insecticidal formulations (emulsifiable concentrate) thereof, are prepared from purified neem kernel extract, with an active ingredient content of 0.3% to 4% and characterized by the absence of gums and aflatoxin spores, for example. The aforementioned formulations contain solvents belonging to the class of aliphatic dihydroxylated alcohols of more than 80% by volume and optionally containing sunscreens and antioxidants.

Method for producing azadirachtin by cell culture of Azadirachta indica

Abstract: A plant cell suspension culture to derive azadirachtin-producing cells is described. The culture overcomes the disadvantages of the present processes of seed extraction. The culture allows for the continuous production of azadirachtin that is free of pathogens and toxins, independent of environmental conditions. It yields a predictable quantity and quality of bioactive product and permits continuous production at a desired, contained location.

Distribution of VAM Fungi in Nurseries and Plantations of Neem ( Azadirachta indica ) in Arid Zone of Rajasthan

Abstract: Occurrence of VAM fungi is ubiquitous and are found in most ecosystems including arid- and semi-arid deserts. A survey for collection of roots and rhizosphere soil samples of neem from various Forest Department nurseries and plantations in arid zone of Rajasthan revealed variation in per cent root infection and number of VAM propagules in the rhizosphere soil samples. It has been observed that mean number of VAM fungal propagules and per cent root infection were greater in plantation samples than in nursery samples. Different VAM fungi have been isolated, of which the genus Glomus is dominant with an exception of Sclerocystis in plantations. Among the Glomus spp., G. fasciculatum is the most predominant one in both nursery and plantation. The significance of these findings is discussed.

Influence of insecticidal plant materials used during storage on sensory attributes and instrumental hardness of dry edible beans ( Phaseolus vulgaris L.)

Abstract: Three plant products with known insecticidal properties, a dry extract of flowers ofChrysanthemum cinerariaefolium (Trevir.) Vis. produced in Rwanda, an ethanol extract of seeds of neem,Azadirachta indica A. Juss., and crushed leaves ofTetradenia riparia Hochst Codd., a traditional Rwandan medicine, were mixed with beans,Phaseolus vulgaris L., for storage protection. These plant-protected beans were compared with ‘off the shelf’ beans that were being sold to consumers by the Rwandan National Agricultural Products Marketing Organization (OPROVIA). A trained sensory panel determined that beans treated with neem andC. cinerariaefolium were as acceptable after 8 months storage as those being sold throughout Rwanda by the marketing organization. Beans marketed by this organization were all treated with the standard insecticide application in Rwanda, 0.01% weight/weight pirimiphos methyl in a powder formulation. Instrumental hardness (% hard-to-cook/mean gram force) after 20 months of storage was acceptable for beans stored with neem or withC. cinerariaefolium or with the conventional government application of pirimiphos methyl. Use of either neem orC. cinerariaefolium for storage protection should not affect consumer acceptance of dry beans.

Root-rot of neem (Azadirachta indica) caused by Ganoderma applanatum.

Abstract: Root rot of neem ( Azadirachta indica ) is a serious disease caused by Ganoderma applanatum is recorded for the first time from Garo Hills (Meghalaya) even from north-east. Symptoms of the disease, morphology of the pathogen and its identification has been described in this paper.