Neem Preparations Research Articles

Bazı biyopreparatların Pamuk beyazsineği ve Domates güvesi’ne laboratuvar koşullarında etkinliği

Amaç: Bu çalışma Azdirachta indica A. Juss (Meliaceae) ve Melaleuca alternifolia (Maiden & Betche) Cheel (Myrtaceae) bitkilerinden elde edilen ve farklı oranda biyoaktif içeren biyopreparatların Bemisia tabaci Genn. (Hemiptera: Aleyrodidae) nimfleri ve Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) larvaları üzerindeki öldürücü etkisinin belirlenmesi amacıyla gerçekleştirilmiştir.Materyal ve Yöntem: Laboratuvar çalışmalarında iki farklı bitki ekstraktından elde edilen 11 preparatın ve 2 ticari neem preparatının % 0,5; % 1,0 ve % 1,5’luk solüsyonlarının Pamuk beyazsineği ve Domates güvesi üzerine insektisidal etkileri yaprak daldırma yöntemi kullanılarak belirlenmiştir.Bulgular: Preparatların etki oranı doz artışıyla birlikte yükselmiştir. En yüksek dozda B. tabaci ile yürütülen denemelerde uygulamadan yedi gün sonra yapılan değerlendirmelere göre; Çay ağacının Alfa tops bileşenlerini içeren preparatları % 67.37 ile 75.79, Gamma tops bileşenlerini içeren preparatları %93.68 ile 97.89 ve Neem ekstraktları içeren preparatlar ise %91.93 ile 95.79 arasında etki göstermiştir. T. absoluta ile yürütülen denemelerde ise uygulamadan on gün sonra yapılan değerlendirmelere göre; Çay ağacının Alfa tops bileşenlerini içeren preparatları %40.00 ile 70.00, Gamma tops bileşenlerini içeren preparatları %82.50 ile 95.00 ve Neem ekstraktları içeren preparatlar %87.50 ile 97.50 arasında etki göstermiştir. Her iki zararlıya karşı ticari neem preparatları ise %100 etki göstererek en etkili preparatlar olmuştur.Sonuç: Çay ağacının Gamma tops bileşenlerini içeren preparatları ile Neem ekstraktı içeren preparatların %1 ve % 1,5’lik dozlarının Bemisia tabaci ve Tuta absoluta’yı önemli oranda kontrol edebileceği laboratuvar koşullarında belirlenmiş olsa da bu verilerin arazi çalışmalarıyla desteklenmesi gerektiği düşünülmektedir.

Transmission blocking activity of Azadirachta indica and Guiera senegalensis extracts on the sporogonic development of Plasmodium falciparum field isolates in Anopheles coluzzii mosquitoes.

BackgroundTargeting the stages of the malaria parasites responsible for transmission from the human host to the mosquito vector is a key pharmacological strategy for malaria control. Research efforts to identify compounds that are active against these stages have significantly increased in recent years. However, at present, only two drugs are available, namely primaquine and artesunate, which reportedly act on late stage gametocytes.MethodsIn this study, we assessed the antiplasmodial effects of 5 extracts obtained from the neem tree Azadirachta indica and Guiera senegalensis against the early vector stages of Plasmodium falciparum, using field isolates. In an ex vivo assay gametocytaemic blood was supplemented with the plant extracts and offered to Anopheles coluzzii females by membrane feeding. Transmission blocking activity was evaluated by assessing oocyst prevalence and density on the mosquito midguts.ResultsInitial screening of the 5 plant extracts at 250 ppm revealed transmission blocking activity in two neem preparations. Up to a concentration of 70 ppm the commercial extract NeemAzal® completely blocked transmission and at 60 ppm mosquitoes of 4 out of 5 replicate groups remained uninfected. Mosquitoes fed on the ethyl acetate phase of neem leaves at 250 ppm showed a reduction in oocyst prevalence of 59.0% (CI95 12.0 - 79.0; p < 10-4) and in oocyst density of 90.5% (CI95 86.0 - 93.5; p < 10-4 ), while the ethanol extract from the same plant part did not exhibit any activity. No evidence of transmission blocking activity was found using G. senegalensis ethyl acetate extract from stem galls.ConclusionsThe results of this study highlight the potential of antimalarial plants for the discovery of novel transmission blocking molecules, and open up the potential of developing standardized transmission blocking herbal formulations as malaria control tools to complement currently used antimalarial drugs and combination treatments.

Effect of a Neem preparation on reproduction of the nematode Globodera rostochiensis and growth of potato

An experiment was conducted under glasshouse conditions to test the effects of neem-based product in the form of drenches and potato tuber treatments on the growth of potato and population density of the potato cyst nematode Globodera rostochiensis. The soil applications of the biopreparation improved the plant growth and yield of potato, being greatest with 1% Neem Azal. The biggest increase in the yield occurred in the Oxamyl application (15.8%). The biopreparation in concentrations from 0.2% to 1% increased the yield of potatoes from 0.3% to 9.7% compared to the untreated inoculated control. The soil application was relatively more effective in increasing of the yield (0.3%-9.7%) than the potato tuber treatments (0.3%-2.3%). The nematode reproduction was reduced 83.3% with Oxamyl and from 59.8% to 71.0% with Neem Azal treatments.

Larvaecidal effects of azadirachtin on the pine processionary moth

The effects of azadirachtin, a natural extract of the neem tree Azadirachta indica A. Juss, on larval growth and feeding activity of pine processionary moth (Thaumetopoea pityocampa (Schiff.)) was investigated in laboratory experiments conducted in 2007 - 2008. The organic insecticide NeemAzal-T/S (a commercial neem preparation) was applied as suspension in distilled water at concentration levels of 0.3, 0.5 and 1%. Comparing with the untreated leaves, the effect of the insecticide NeemAzal-T/S was tested on the 10 th day after treatment. The results obtained in conducted experiments indicated that NeemAzal-T/S was effective against T. pityocampa larvae, significantly inhibiting larval growth and reducing feeding activity.

ORGANIC FRUIT PRODUCTION IN EUROPE: SUCCESSES IN PRODUCTION AND MARKETING IN THE LAST DECADE, PERSPECTIVES AND CHALLENGES FOR THE FUTURE DEVELOPMENT

The organic market has grown exponentially in Europe during the last ten years. However, the organic fruit industry in European states still has a relatively low market share of less than 1-5% compared with organic vegetables, milk and eggs that have achieved market shares of close to 10% of the total market. As well, conventional fruit growers still hesitate to respond to the generally good organic market demand. A major reason for this behaviour is the continuing high production risk due to less availability of effective management tools for the control of pests, diseases, weed and biennial bearing. The key pests and diseases in apple and pear include scab, sooty blotch, and fire blight as well as rosy apple aphid, pear sucker and codling moth, as well as post-harvest diseases like Gloeosporium rot. Another reason that holds up organic fruit expansion is that in fruit production, in contrast to milk or wheat, new and organic-specific marketing attempts are necessary for organic cultivars, less cosmetic “beauty”, etc.) but are presently scarce. In an ideal organic production system, all possible measures that lead to improved stability and self-regulation of the agro-ecological system have to be implemented (e.g. resistant cultivars, bio-diversity areas, lower planting densities, measures to avoid inoculum build-up, soil fertility). At present, most organic orchards have almost the same design as found in conventional production and often do not include system stabilising elements. Therefore, organic fruit production still depends largely on direct pest and disease control methods. In the last decade effective compounds and techniques have been developed such as Neem preparations, granulosis viruses, and mating disruption to control pests. Some new plant protection techniques e.g. clay powders, resistance inducers, better spray technique and spray timing models have been introduced. The introduction of new equipment, compounds, cultivars and decision support systems will further improve yield stability. However, for other limiting factors, such as weed competition, crop load regulation and market demands in respect to quality, innovative solutions have to be developed. The challenge for the future is to build up a credible (“true-organic”) and high quality multi-factor oriented organic fruit production that combines single factor solutions to a self-regulating, and possibly even organic pesticide-free, production system. Progress in this direction will lead to innovative organic production and marketing concepts that are clearly different from conventional ones. To achieve these goals, creative efforts along the whole chain involving producers, consumers, retailers, advisory services and researchers are essential.

Effects of different neem preparations in comparison to synthetic insecticides on the whitefly parasitoid Encarsia sophia (Hymenoptera: Aphelinidae) and the predator Chrysoperla carnea (Neuroptera: Chrysopidae) on cotton under laboratory conditions

The contact and feeding toxicity of NeemAzal T/S (EID Parry, Chennai, India) to the parasitoid Encarsia sophia (Girault & Dodd) was compared with three synthetic insecticides (chlorpyriphos, endosulfan and triazophos) against immatures and adult emergence. NeemAzal T/S (1.0%) at lower dose (200 mg/l) did not cause any effect on the emergence of E. sophia adults, but there was a significant reduction in emergence at higher doses (800 mg/l). Also, it did not show contact toxicity to adults of E. sophia, but there was a significantly high feeding mortality in a dosage dependant manner, whereas chlorpyriphos, endosulfan and triazophos showed high toxicity both by contact and feeding method. Three neem preparations registered in India, NeemAzal T/S, Nimbecidine (T. Stains, Coimbatore) and Godrej Achook (Godrej Agrovet, Mumbai) were tested against egg and larval stages of Chrysoperla carnea (Stephens) at three dosages, using a synthetic insecticide, triazophos 40 EC (200 mg/l), for comparison under laboratory conditions. The three biorationals did not induce any adverse effect on the hatchability of C. carnea eggs. The mortality of the first instars of C. carnea was not affected by any of the azadirachtin enriched formulations; however, at higher dosage of 800 mg/l these neem based products resulted in increased mortality of the first and second instar larvae of C. carnea relative to the untreated controls. Whereas, triazophos induced very high mortality rates (85.0, 89.0 and 81.5%) of all the three larval instars. The neem based insecticides showed a dosage-dependant effect on the larval instars of C. carnea. Thus, these biorationals show that there is a potential to use them in an IPM system, being safe for natural enemies of B. tabaci in cotton.

The different effects of two preparations of neem (Azadirachta indica) and of Sumicidin® on the aphid predator Hippodamia variegata (Goeze) (Coleoptera: Coccinellidae)

Greenhouse experiments were conducted at Khartoum (Sudan) with the aphid predator Hippodamia variegata, two botanical and one synthetic insecticides: neem seed water extract (25 g fresh seed powder per l of water), NeemAzal T/S® (1 % azadirachtin A) and fenvalerate (Sumicidin® 20 % EC). An equivalent of 400 l/ha was applied with a plastic hand sprayer, containing 0.2 l Sumicidin (40 g/ha fenvalerate), 1.6 l NeemAzal (16 g/ha azadirachtin A) or 10 kg of neem seed powder (ca. 30 g/ha azadirachtin A was applied as neem seed water extract). The beetles were fed on Aphis gossypii reared on cucumber leaves. Four different stages of the predator were sprayed topically with the test preparations. In addition, beetles were fed on A. gossypii either topically sprayed or collected from cucumber plants, which soil was treated four days earlier. The preparations varied in their effects on the different stages of the predator. Neem weed water extract was less harmful to the predator than NeemAzal T/S. In topical treatments with NeemAzal T/S the corrected mortality (%) was: eggs 37.7, larvae 40.0, pupae 38.2, and adults 16.7; with neem seed water extract: eggs 15.1, larvae 26.7, pupae 29.4, and adults 10.0; with fenvalerate: eggs 86.8, larvae 100, pupae 73.5, and adults 100. Feeding L2 larvae and adults on contaminated aphids resulted in the following corrected mortalities (%): Sumicidin 100, NeemAzal ca. 40 and neem seed water extract 20/17 (larvae/adults). Feeding on aphids treated via the soil with neem seed water extract resulted at maximum in 26.4/16.7 % corrected mortality (larvae/adults), while no effects on the longevity of adults could be observed. So, in contrast to Sumicidin, neem preparations (being effective against pests) proved to be harmless for the beneficial beetle. The results are discussed concerning their importance for plant protection.

Effects of neem‐treated aphids as food/hosts on their predators and parasitoids

Abstract: Experiments were conducted in the laboratory and in greenhouses. Of three neem preparations sprayed upon eggs, only neem oil (NO) exerted a negative impact on the hatching rate of Coccinella septempunctata and Chrysoperla carnea. First instar larvae of Episyrphus balteatus proved to be highly susceptible, when feeding 24 h on aphids sprayed with neem kernel water extract (NKWE). First instar larvae of C. septempunctata showed a very high mortality when feeding on aphids sprayed with different neem preparations. Aphid feeding and live span was reduced. When NKWE had been applied to the soil, the mortality of larvae of E. balteatus and C. septempunctata were lower, when feeding on aphids. Second instar larvae of C. septempunctata were far less susceptible when feeding 48 h on neem‐sprayed aphids than first instars; the time of their development was prolonged, and aphid consumption reduced. Larvae of C. carnea proved to be less susceptible, when feeding on neem‐sprayed aphids, than E. balteatus and C. septempunctata. In C. carnea, however, significant influences were also observed in aphid consumption, time of development, mortality, longevity, and rate of deformity. NO, containing a very low concentration of azadirachtin A, had stronger negative effects than NeemAzal‐T/S®, in all observations. In the parasitoid Diaeretiella rapae, NKWE application to the soil induced negative reactions, when aphids on these plants were parasitized: low percentage parasitization, lowered mummy weight, low emergence rate of adults of F1 and even of F2. Foliar sprays of NKWE had less severe effects in this parasitoid species. The results are discussed with regard to their theoretical and practical significance.

The efficacy of different neem preparations for the control of insects damaging potatoes and eggplants in the Sudan

In greenhouse (Khartoum, Sudan), the effect of NeemAzal-T/S® (NA, at 20 g a. i. ha −1) on mortality of third instar nymphs of Jacobiasca lybica was not significantly different from that of Omethoate at 200 g a. i. ha −1. Neem oil (at 0.2 g a. i. ha −1) was less effective. In two semi-field tests, numbers of J. lybica and potato yield were negatively correlated. The percentage yield losses were equal in both years. Two field experiments conducted in potato, using a VLV-technique with weekly treatments of 20 l ha −1, showed similar mortality by NA and fenvalerate (20% EC at 140 g a. i. ha −1) in J. lybica and Bemisia tabaci. In Aphis gossypii, fenvalerate exerted a stronger effect (84%) than NA (77%). Potato yield was highest in NA and fenvalerate, lower in neem kernel water extract (NKWE; with 2–5 g a. i. ha −1), and equal to water treatment in neem oil (NO). In three similar field experiments in eggplant (aubergines), fenvalerate reduced J. lybica, B. tabaci and A. gossypii by 92%, 70% and 82%, respectively, followed by NA (86%, 61% and 78%). NO and NKWE were less effective. Eggplant yield was highest following NA-treatment, fenvalerate having a lower yield in one of the experiments. NO and NKWE increased the yield in only one of the three experiments. In eggplant, the frequency of stenophagous antagonists of the homopterous pests was affected negatively by fenvalerate, resulting in an unfavourable prey/predator ratio. The neem preparations induced only mild reduction of the antagonists, producing a favourable prey/predator ratio. Based on availability, the effects on pests, beneficials, and on yield, the use of NKWE may be recommended for plant protection in vegetables in the Sudan. Optimal concentrations, in excess of 2–5 g a. i. ha −1, as used here, and new formulations remain to be studied.

Lethal and sublethal effects of a neem-based insecticide on balsam fir sawfly (Hymenoptera: Diprionidae).

Lethal and sublethal effects of Neemix 4.5 EC, a commercial neem preparation, on balsam fir sawfly, Neodiprion abietis (Harris), were determined in the laboratory. Larval mortality of N. abietis increased in a concentration-dependent manner, and lethal time decreased with increasing Neemix 4.5 EC concentration. Fifty percent of the larvae died after 4.6 d at a concentration of 90 ppm azadirachtin (AZA) and 12.3 d at a concentration of 0.08 ppm. Neemix 4.5 EC showed some deterrent effects to feeding site selection on N. abietis larvae at high concentrations, but not at low concentrations. Strong reduction of food intake by N. abietis larvae after exposure to Neemix 4.5 EC was demonstrated by significant reduction of frass production. Larvae fed on Neemix 4.5 EC-treated foliage at 90 ppm AZA produced only 16% as much frass as that produced by larvae fed on control foliage (0 ppm). Neemix 4.5 EC at a concentration of 0.08 ppm AZA retarded larval and pupal development. Sublethal doses significantly reduced pupal weight and adult emergence, although the sex ratio of N. abietis adults was not affected. Results indicate that sublethal effects of Neemix 4.5 EC on N. abietis may contribute greatly to the overall field efficacy.

Effect of antifeedants on the diamondback moth (Plutella xylostella) and its parasitoidCotesia plutellae

Two neem preparations and the bitter-tasting synthetic chemical denatonium benzoate were tested in the laboratory as antifeedants against the diamondback moth, Plutella xylostella L. The effects of the three materials on Cotesia plutellae (Kurdjumov), a hymenopteran parasitoid of ­P xylostella, were also recorded. All three materials significantly reduced the food consumption of ­P xylostella larvae. Parasitoid cocoons were formed on approximately half of those larvae which had been exposed to female C plutellae, regardless of antifeedant treatment, but emergence of adult parasitoids from the cocoons was significantly reduced by antifeedant treatment. In terms of food consumption and mortality of unparasitised P xylostella larvae, and emergence of adult C plutellae, the effect of each antifeedant preparation was directly related to the concentration of material used, but the effects of the neem preparations were greater than those of denatonium benzoate. However, no adult P xylostella emerged on any antifeedant treatment, therefore some of the parasitoids survived antifeedant treatments which were fatal to the unparasitised hosts. © 2000 Society of Chemical Industry

Effect of NeemAzal, a natural azadirachtin‐containing preparation, on Periplaneta americana (L.) (Orthopt., Blattidae)

AbstractNeemAzal, a commercial neem preparation with an azadirachtin content of 20%, was proven to be a growth retardant for the cockroach Periplaneta americana. As shown in the reduction of food consumption, the effect of NeemAzal, ingested as food, is predominantly to interpret as a phagodeterrent effect. The decreased ingestion of food results in a retardation of growth of the larvae and finally in a reduction of the reproductivity of the adults. The results suggest that a long‐term decimation of a population with a small fluctuation until its breakdown by intensive and permanent offering a NeemAzal‐containing bait may be possible.

Evaluation of neem as a bird repellent chemical

Abstract Neem extract (Azadirachta indica) is effective as an insect antifeedant, and limited evidence suggests that it may be useful as a repellent for birds. The present experiments were designed to test this proposition. In Experiment 1, European Starlings [Sturnus vulgaris) were presented with feed adulterated with a commercially available neem preparation (Nimin®). The results showed that the highest test concentration (1.5% m/m) was avoided. In Experiment 2, starlings were presented with an aqueous extract of neem leaves and serial dilutions of that extract. All extract concentrations were avoided relative to untreated water. We conclude that neem is an economical and biologically safe bird repellent and that it may be useful in developing nations where neem is indigenous or introduced, and when synthetic pesticides are difficult to obtain or expensive.

Nonconventional insecticidal effects of pesticides available from the Neem tree, Azadirachta indica

AbstractNonconventional insecticidal effects are exerted by preparations from the Neem tree, also called Indian lilac or Margosa tree (Azadirachta indica A. Juss, syn. Melia azadirachta L. or Antelaea azadirachta L.) (Meliaceae). A closely related species, the chinaberry tree or Persian lilac (Melia azedarch L.), is a source of substances with similar strctures and insecticidal activity. However, the seed kernels, whole fruits or leaves of many M. azedarch chemotypes contain tetranortriterpenoids and other principles highly toxic to mammals (meliatoxins). The most prominent insecticidal constituent of Neem seed kernels is the tetranortriterpenoid azadirachtin and related structures. Lesser concentrations of these active materials are found in the leaves and other parts of the tree. Third World farmers use crude Neem preparations, mainly seed kernel extracts or powders, as insecticides. An industrial Neem product, called Margosan‐O, is in commercial use in the USA. The nonconventional effects of preparations or compounds isolated from Neem may be classified as follows: (i) partial reduction or complete inhibition of fecundity and/or sometimes egg hatchability; (ii) reduction of the life span of adults; (iii) oviposition repellence against females; (iv) direct ovicidal effects; (v) antifeedant effects against larvae (and nymphs) and adults; (vi) formation of permanent larvae; (vii) insect growth regulator effects at molting between larval (or nymphal) instars and especially in the prepupal stage; and (viii) analogous lesions during the emergence of adults. Phenomena (vii) and (viii) give rise to characteristic larval‐pupal, nymphal‐pupal, nymphal‐adult and pupal‐adult intermediates, and to crippled adults. © 1993 Wiley‐Liss, Inc.