Showing papers on "Azadirachta published in 1990"

Properties and potential of natural pesticides from the neem tree, Azadirachta indica.

Abstract: Les substances derivees du «neem», efficaces contre les insectes sont examines (influence sur le comportement de fixation, la ponte, la prise de nourriture, la metamorphose, la fecondite, la fitners) ainsi que les capacites potentielles des insecticides extraits du neem pour le controle des insectes nuisibles et leurs effets sur les animaux a sang chaud et sur l'homme

Properties and uses of neem, Azadirachta indica

Abstract: The versatility of the neem tree Azadirachta indica A. Juss. is reviewed. This species, native to India, grows in nutrient-poor soils in arid habitats and has tremendous potential for human use. Va...

Repellent and Feeding Deterrent Effects of Turmeric Oil, Sweetflag Oil, Neem Oil, and a Neem-Based Insecticide Against Lesser Grain Borer (Coleoptera: Bostrychidae)

Abstract: Repellency of oils of turmeric, Curcuma longa (L.), sweetflag, Acorus calamus (L.), neem, Azadirachta indica A. Juss, or a neem-based insecticide (Margosan-O, Vikwood Botanicals, Sheboygan, Wis.) was monitored against the lesser grain borer, Rhyzopertha dominica (F.), for 8 wk. In a choice test, filter paper strips treated with the test materials at 200,400, or 800 μg/em2 repelled the insect. Turmeric oil and sweetflag oil were significantly more repellent during the first 2 wk than neem oil and Margosan-O, but thereafter, their repellency decreased more rapidly than that of neem oil or Margosan-O. R. Dominica adults made significantly fewer and smaller feeding punctures in filter paper disks (7 em diameter) treated with the test materials at 100, 500, or 1,000 μg/em2 than in control disks. Because of greater persistence, neem oil and Margosan-O deserve to be evaluated in field trials against storage pests.

Antifertility effects of leaf extracts of some plants in male rats.

Abstract: Ethanolic leaf extracts of different local folklore plants (Azadirachta indica, Beaumontia grandiflora, Chordia dichotoma, Casiarea tomentosa, Diospyros embryopteris, Milletia auriculata and Melia azedarach) were investigated for antifertility effects on male rats in oral doses of 100 mg/kg daily for 21 days. Though, none of these extracts interfered with spermatogenesis, anti-implantational and abortifacient effects were observed in females mated by the males fed with leaf extracts of A. indica and C. dichotoma. Leaf extract of B. grandiflora besides having anti-implantational and abortifacient effects, had luteolytic effects. Abolition of libido in 100% males by leaf extracts of D. embryopteris and M. azedarach and in 60% of males by extract of C. tomentosa preclude these plants for antifertility use.

Antifertility effects of neem (Azadirachta indica) oil by single intrauterine administration: a novel method for contraception.

Abstract: A novel use of neem (Azadirachta indica) oil, a traditional plant product, for long-term and reversible blocking of fertility after a single intrauterine application is described. Female Wistar rats of proven fertility were given a single dose (100 microliters) of neem oil by intrauterine route; control animals received the same volume of peanut oil. Whereas all control animals became pregnant and delivered normal litters, the rats treated with neem oil remained infertile for variable periods ranging from 107 to 180 days even after repeated matings with males of proven fertility. The block in fertility was, however, reversible as half of the animals regained fertility and delivered normal litters by five months after treatment, without any apparent teratogenic effects. Unilateral administration of neem oil in the uterus blocked pregnancy only on the side of application whereas the contralateral uterine horn treated with peanut oil had normally developing foetuses; no sign of implantation or foetal resorption was noted in the neem-oil-treated horn. The ovaries on both sides had 4-6 corpora lutea indicating no effect of treatment on ovarian functions. The animals treated with neem oil showed a significant leukocytic infiltration in the uterine epithelium between days 3 and 5 post coitum, i.e. during the pre-implantation period. Intrauterine application of neem oil appears to induce a pre-implantation block in fertility; the possible mechanisms of the antifertility action are discussed.

The efficacy of seed oils of Azadirachta indica A. Juss and Piper guineense Schum and Thonn on the control of Callosobruchus maculatus F.

Abstract: Oils from the seeds of neem, Azadirachta indica A. Juss and from a brown pepper, Piper guineense Schum and Thonn afforded protection to cowpea seeds from Callosobruchus maculatus infestation beyond 3 months. Insecticida! efficacy was higher with Piper seed oil (PSO). At 24 hr after surface treating cowpea seeds with 2 and 3 ml/kg of PSO, bruchid mortality reached 100 %, but with neem seed oil (NSO), mortality was 65–100% at 3–5 days. Oviposition in control averaged 60.75 eggs, 49.5 eggs in NSO and 15.5 with PSO. Reproductive efficiency (RE) of PSO-treated females was nil, and very low (1.7 to 2%) with neem oil, but high in control confirming adverse ovicidal effects of both oils. Piper oil prevented emergence of F1 bruchids and neem oil prolonged their mean development period over the control. Neem oil reduced seed damage by 94.67%. Because Piper seeds are a condiment in some Nigerian dishes, and are also used therapeutically in many traditional diseases, there may be no toxicity. However, yield of PSO is much less than that of neem from an equal weight of seeds extracted with organic solvents.

Effect of Vegetable Oils on the Ovipositional Behaviour of Callosobruchus Maculatus (Fabricius)

Abstract: Effects of nine vegetable oils viz., Pongamia glabra, Madhuca indica, Ricinus communis, Brassica sp., Azadirachta indica, Cymbopogon citratus, Cocos nucifera, Cymbopogon nardus, and Arachis hypogea at three different concentrations (0.2, 0.4, and 0.8% w/w) were studied on the oppositional behaviours of Callosobruchus maculatus (Fabricius) at 27 ± 1°C and 70% R.H. Oviposition was completely inhibited by the seed treatment of Pongamia oil in each dose just after the treatment but its efficacy sharply deteriorated at later stages of sampling (30, 60 and 90 days after treatment). Cymbopogon nardus and C. citratus oils were effective even up to 90 days of treatment. Dose to dose variations were significant at each stage of sampling.

Effects of cypermethrin + dimethoate and extracts of Piper guineense and Azadirachta indica on the pests and yield of cowpea, Vigna unguiculata.

Abstract: Field trials were conducted in 1988 at the University of Ibadan to determine the effects of cypermethrin + dimethoate (Sherpa Plus®), the oil extract from ripe seeds of Piper guineense Schum & Thonn and the aqueous extract of ripe seeds of Azadirachta indica A. Juss on the pests and yield of cowpea. Cypermethrin + dimethoate was consistently superior to all other treatments in substantially reducing the population densities of Megalurothrips sjostedti Trybom and of Maruca testulalis Geyer, which are serious pests on flowers and buds, and in reducing the densities of four pod-sucking bugs. Pest population densities were also reduced by foliar sprays with A. indica or P. guineense extracts. Seed yield after treatment with cypermethrin + dimethoate was 0·99 t/ha, more than double the yield from other treatments. A marginal increase in seed yield compared with the control was achieved by foliar spraying with A. indica extract.

Insecticidal Actions of Several Plants to Callosobruchus Chmensis L.

Abstract: Nine plants were evaluated for their insecticidal actions on Callosobruchus chinensis L: Agcratum conyzoides, Blumea baJsimifera, Chrysanthemum indicum, Coleus amboinicus, Vitex negun-do, Azadirachta indica, Cocos nucifera, Capsicum frutesccns and Piper nigrum. By filter paper impregnation method, the oils of the first seven plants exhibited contact toxicity with mortality ranging from 66 to 100% at 100 mg/ml, 48 hrs after exposure. At the same concentration, the oils were more toxic when mixed with the seeds, giving 100% mortality at 24 hours. C. amboinicus oil was the most toxic causing 93% mortality at 10 mg/ml within 15 minutes exposure, while the rest of the oils gave mortalities ranging from 43 to 100% 24 hours after exposure. Seed treatment at 5 mg inhibited egg laying by 71 to 100%. Mungbean seed treated with ground P. nigrum and C frutescens at 600 ppm was very toxic (91% mortality) after 48 hours exposure and was residually toxic 6 months after treatment to the weevils. P. nigrum inhibited the development of Fl progenies. Exposure of the bean weevil to mungbean treated with oils/extracts/powders from the test plants exhibited one or a combination of the following actions: toxicity, repellancy, antioviposition and growth inhibition. GC-mass infrared analysis of the volatile oil from sambong and its fractions showed the presence of sesquiterpe-noidal compounds. Purification and identification of the active compounds are in progress.

Explanations for the differential response of certain tropical tree species to SO2 under field conditions

Abstract: Four different tree species, Zizyphus mauritiana, Syzygium cumini, Azadirachta indica and Mangifera indica were analyzed for stomatal conductances, sulphate, protein, superoxide dismutase and peroxidase activities for one complete year in an ambient environment with SO2 concentrations ranging between 90 to 10 ug m−3. The low conductances, declined protein content and enhanced sulphate content, superoxide dismutase (SOD) and peroxidase (POD) activities were the general responses exhibited by these species when compared with to the reference site. The pattern of the results indicate that plants under SO2 stress develop an ability to detoxify the phytotoxicity by undergoing certain biochemical changes. Plants which posses high intitial POD activities coupled with greatly enhanced SOD activity (Z. mauritiana) or plants which can enhance both POD and SOD activities (S. cumini) were more tolerant/least affected than that of A. indica and M. indica.

Beobachtungen an Schädlingen von Azadirachta indica (Niembaum) und von verschiedenen Melia-Arten

Abstract: Observations on pests of Azadirachta indica (neem tree) and of some Melia species The neem tree, Azadirachta indica, is attacked by a number of pest species but most of them are only slightly harmful. Some scale insect species, such as Pinnaspis strachani and Aonidiella orientalis, may be very numerous but are usually kept in check by natural enemies. Leaf cutting ants (Acromyrmex sp.) damage young trees in Latin America. The tortricid moths Adoxophyes aurata and Loboschiza sp. attack neem leaves in SE-Asia and W-Africa, respectively. The former may cause considerable damage to leaves of chinaberry whereas Pseudalacaspis pentagona may kill twigs and branches of the same plant species during outbreaks in Tonga. Zusammenfassung Der Niembaum Azadirachta indica wird von einigen Schadlingen befallen, jedoch sind die meisten nur von geringer Bedeutung. Manche Schildlausarten wie Pinnaspis strachani und Aonidiella orientalis konnen sehr zahlreich sein, werden in der Regel aber durch naturliche Feinde in Schach gehalten. Blattschneiderameisen (Acromyrmex sp.) entblattern junge Niembaume in Lateinamerika. Der Wickler Adoxophyes aurata frist in Sudostasien an den Blattern, Loboschiza sp. in Afrika. Am Persischen Flieder Melia azedarach kann die erstgenannte Art betrachtlichen Schaden verursachen; die Schildlaus Pseudalacaspis pentagona bringt bei Massenvermehrung in Tonga Zweige und Aste der gleichen Meliacee zum Absterben.

Tricyclic Diterpenes from the Stem Bark of Azadirachta indica.

Abstract: Two new diterpenoids, margosone and margosolone, have been isolated from the stem bark of Azadirachta indica A. Juss (neem) and their structures established as 12,13-dihydroxy-14-isoporpylpodocarpa-8,11,13-trien-7-one and 13-hydroxy-12-methoxypodocarpa-8,11,13-trien-7-one, respectively, through chemical and spectroscopic studies.

Effect of Margosan-O on the development of Earias insulana.

Abstract: The effect of Margosan-O, a formulation of a natural insecticide obtained from the neem tree (Azadirachta indica A. Juss), on the development of and the penetration rate of larvae of the spiny bollworm,Earias insulana (Boisd.), into cotton bolls was investigated by (i) incorporating Margosan-O into a semisynthetic diet and recording mortality until the adult stage; and (ii) spraying leaves and bolls with, or standing cotton seedlings or twigs of cotton with one boll per twig in aqueous dilutions of Margosan-O in an attempt to protect leaves or cotton bolls from feeding or penetration, respectively, by the larvae. Margosan-O was found to be effective when incorporated into the semisynthetic diet, even at low concentrations, especially when it was offered throughout the larval life span. Survival rate and average weight of the larvae were much lower on leaves treated with 0.5% or 0.2% Margosan-O, or exposed to its systemic effect at 0.5% or 0.25%, than on control leaves. Larval penetration into Margosan-O-sprayed bolls at concentrations of 0.01– 0.5% wasca 30–45% of that into control bolls. Margosan-O was active also as systemic treatment: onlyca 35% of the larvae penetrated the 0.25%-treated bolls compared with the untreated ones.

Fertilizer application in aid of plantation establishment in the savanna areas of Nigeria

Abstract: Fertilizer trials were conducted to stimulate tree establishment and growth in the savanna region of Nigeria. The main nutrients investigated were N, P, K and B while the tree species included Azadirachta indica (Neem), Acacia auriculiformis, Eucalyptus spp., and Pinus spp. Borate application reduced the incidence of die-back of eucalypts and it also increased height growth. There was positive response to phosphate application by all species; phosphate reduced mortality considerably in pines on some sites. Response to N fertilizer by the species varied and related to type of N fertilizer. Urea was often found injurious to pines. There was strong interaction between N and P and usually response to N was not obtained on P-deficient sites. In all the cases where it was applied, there was no response to K. On more arid sites with poorly buffered soils, mineral fertilizers alone were insufficient to produce satisfactory tree growth. Application of animal manure on such sites increased survival and growth of Azadirachta indica, E. camaldulensis and A. auriculiformis.

Inhibition of seed germination by the endocarp in Neem (Azadirachta indica A. Juss.)

Abstract: The endocarp inhibited the seed germination in neem (Azadirachta indica A. Juss.) by delaying the initiation of germination and lowering the germination percentage to about three to four times. The endocarp not only acted as a physical barrier but also seemed to contain some inhibitory substance (s) which possibly acted as a metabolic barrier during seed germination.

Solvent Extracted Neem (Azadirachta indica) A. Juss) Seed Cake in the Ration of Growing Crossbred Calves

Abstract: Effect of Incorporation of 45% solvent extracted neem (Azadirachta indica A. Juss) seed cake (DNSC) in the concentrate mixture of growing crossbred calvess,6-9 m; 67-156 kg) was studied and compared with those fed control concentrate mixture. A. significant (P<0.01) depression In the growth rate of DNSC fed group was observed within a period of 75 d. Inspite of the bitters present, increased DM Intake in the DNSC group than nhe eontrol group indicated the good acceptability of the DNSC. However, the digestibility of all the nutrients and retention of N and Ca were significantly low under the DNSC ration. A reduction of 17% in the TDN Intake, inspite of high DM intake, could not explain for 46% depression in the growth rate of calves in the DNSC group. It was concluded that the neem bitters available at 45% level of DNSC were responsible for depressing the growth rate.