Neem Formulations Research Articles

Biological Compatibility of Beauveria bassiana (Balsamo) Vuillemin Isolate with Different Insecticides and Neem Formulations Commonly Used in Rice Pest Management

Compatibility of Beauveria bassiana (Balsamo) Vuillemin (isolate BbCm KKL 1100) with twelve insecticides and three neem formulations was examined on agar plate to develop suitable combinations for the management of insect pests in rice fields. All chemical and botanical insecticides inhibited mycelial growth of B. bassiana either partially or completely depending on their concentrations (10X, 1X and 0.1X, where X = treated concentration). Chemical insecticides completely inhibited the mycelial growth of B. bassiana , while the neem formulations inhibited 70-86% biomass production of the fungus at 10X concentration. At 1X concentration, carbofuran caused total inhibition, but all other insecticides caused 47.4-75.5% inhibition. However, at 0.1X concentration, only neem seed kernel extract, chlorpyriphos and dimethoate exhibited 22.2%, 27.3% and 32.6% mycelial inhibition, respectively, and these could be used with B. bassiana in the field condition.

Persistence of Two Neem Formulations on Peach Leaves and Fruit: Effect of the Distribution

Persistence of azadirachtins (A+B) and of the other limonoids (nimbin, salannin, deacetylnimbin, and deacetylsalannin) on peach leaves and fruits was studied using a commercial formulation (form. C) compared with an experimental formulation (form. E) prepared with coformulations allowed in organic culture. Field experiments were carried out using three concentrations: 1x, 5x, and 10x the dose recommended by the manufacturer. The EU maximum residue level (MRL) in fruits and vegetables for azadirachtin A is 1 mg/kg with a preharvest interval (PHI) of 3 days. At the recommended dose, azadirachtin A residue on fruits was not detectable (LOQ < 0.8 microg/kg). After field treatment at the 5x concentration, azadirachtoids were found with 22% in the epicuticular waxes and the remaining 78% on the fruit surface. No residues were found in the fruit pulp. The experimental formulation (E) produced lower residues on leaves and fruit compared with the commercial formulation (C), although formulation E showed greater stability. This is probably due to the amount of the active ingredients that diffuse into the epicuticular wax layer thus enhancing photostability of azadirachtoids.

Seasonal fluctuation in the population of Leucinodes orbonalis Guen. in the sub-himalayan region of West Bengal, India and its control on eggplant (Solanum melongena L.)

Eggplant is one of the most common vegetable crops grown in India and other parts of the world. Leucinodes orbonalis is the key pest infesting eggplant, with international importance as it causes heavy damage in all eggplant growing areas. It is very difficult to control this pest since it feeds inside the shoot and fruit, and there is every possibility of toxic residues remaining in the fruits as they are harvested at frequent intervals and are consumed after little cooking. In the sub-himalayan region of West Bengal, India the pest was found to be most active during summer and the rainy season, particularly during May–August, and caused 49.5–81.0% damage to fruits. Peak infestation (81.0% fruit damage) was noticed in the first week of June (22nd standard week), when the mean temperature, mean relative humidity and weekly rainfall were 27.8°C, 79.2% and 81.2 mm respectively. The pest became less active during winter months particularly in December–January. Borer infestation showed a significant positive correlation (P = 0.05) with maximum and mean temperature, minimum and mean relative humidity and rainfall, whereas with maximum relative humidity the correlation was negative but non-significant. The insecticides evaluated in the field for L. orbonalis control on eggplant revealed that avermectin (Vertimec 1.9 EC; 0.5 ml/l) was the most effective in suppressing dead heart caused by the pest, closely followed by Beauveria bassiana (Biorin 107 conidia/ml; 1 ml/l) and Bacillus thuringiensis Berliner (Biolep 5 × 107 spores/ml; 1 g/l). Significantly lower levels of fruit damage were recorded after avermectin treatment, closely followed by DDVP (0.05%) (Nuvan 76 SL; 2 ml/3 l) when compared with the untreated control. The other insecticides tested, including a neem formulation (Neemactin 0.15 EC; 2.5 ml/l) and malathion (0.05%) (Malathion 50 EC; 1.0 ml/l), were less effective. None of the insecticides evaluated produced satisfactory results against L. orbonalis. However, avermectin, besides being environmentally safe, was effective for a longer duration and could thus be recommended for Integrated Pest Management programmes on eggplant.

A review of neem biopesticide utilization and challenges in Central Northern Nigeria

The status of neem biopesticide research, utilization and challenges in the central part of northern Nigeria was reviewed. In the sampled areas such as the Federal Capital Territory (FCT), Abuja and Niger State, the highest category of neem users (17.19%) were the rural farmers. Majority of the neem users obtained their materials from semi-wild trees on communal land. Our investigations showed that neem leaf and seed powder or extracts controlled weevils in stored maize and cowpea, enhanced germination percentage, and seedling vigour. It also reduced fungal attack and infection on stored seeds and crops on the field. Scale insects were controlled on seed yam dressed with various neem formulations. Application of bionimbecidin HP III (Greengold ® ) paste at 5 g/Kg of seeds for three weeks in storage significantly enhanced seedling vigour and reduced root-rot index on a susceptible cowpea. Increased bioactivity against Rhizoctonia root-rot and Meloidogyne root-knot was achieved through synergism from the combined iron weed and neem leaf extract. Forty seven point two percent (47.20%) of the respondent neem users indicated insufficient supply of commercial neem formulation as their main constraints, while 80.15% complained of inadequate processing facilities. Optimal utilization of neem biopesticide could be achieved in Nigeria by addressing the constraints and challenges in the formulation and standardization of the organic pesticide.

STERILANT AND OVIPOSITION DETERRENT ACTIVITY OF NEEM FORMULATION ON PEACH FRUIT FLY BACTROCERA ZONATA (SAUNDERS) (DIPTERA: TEPHRITIDAE)

ABSTRACT Impact of neem (600, 300, 150, 75, 37.5 and 18.7 ppm) on sterilant and oviposition activity was evaluated on the peach fruit fly Bactrocera zonata (Saunders) (Diptera: Tephritidae) under laboratory conditions using filter paper dip method. Results revealed that neem formulation has a significant effect against eggs of B. zonata at all concentrations used, compared with control. However no effect of neem on the sterilant percent and adults emerged from treated eggs at all concentrations. Moreover, the rate of eggs sterility which produced from treated adults with the previous concentrations was concentration-dependent and significant differences were existed when mated (treated females with normal male and treated female with treated male). While no significant differences observed in treated male mated with normal female. When compared with control (normal male with normal female). The repellency effect of neem on egg deposited in orange fruits after being sprayed with previous concentrations was high and reach to 5.0 % eggs/puncture/fruit, compared with 65.8 % of control. Moreover, the percent of egg hatch decreased to 76.2 % at 600 ppm, compared with 89.0 % of control.

Bioefficacy of Drek (Melia azedarach) seeds against red pumpkin beetel, Aulacophora foveicollis Lucas (Coleoptera: Chrysomelidae)

Red pumpkin beetle Aulacophora foveicollis is a serious pest of cucurbitaceous vegetables. It feeds on the leaves of Cucumber (Cucumis sativus), Ridge gourd (Luffa acutangula) Pumpkin (Cucurbita moschata), Bottlegourd (Langeneria siceraria) etc. Ethanol extract and aqueous extract of Drek (Melia azedarach) seeds was tested against this pest on Cucumber in Punjab. Ethanol extract 1% and aqueous extract 3% were found effective in managing this pest. These were found to be at par with commercial formulations of Neem (Azadirachta indica) viz. Econeem and Nimbecidine in the field trials in managing the insect. In another trial ethanol extract 4ml/l was found to be at par with Econeem against red pumpkin beetle on Cucumber, Ridgegourd and Bottlegourd. As seeds of Melia azedarach are found in considerable quantities, the study has a great scope for promotion of seeds of Melia azedarach as biopesticide.

Insect growth regulator effects of azadirachtin and neem oil on survivorship, development and fecundity of Aphis glycines (Homoptera: Aphididae) and its predator, Harmonia axyridis (Coleoptera: Coccinellidae)

Aphis glycines Matsumura, an invasive insect pest in North American soybeans, is fed upon by a key biological control agent, Harmonia axyridis Pallas. Although biological control is preferentially relied upon to suppress insect pests in organic agriculture, approved insecticides, such as neem, are periodically utilized to reduce damaging pest populations. The authors evaluated direct spray treatments of two neem formulations, azadirachtin and neem seed oil, under controlled conditions for effects on survivorship, development time and fecundity in A. glycines and H. axyridis. Both azadirachtin and neem seed oil significantly increased aphid nymphal mortality (80 and 77% respectively) while significantly increasing development time of those surviving to adulthood. First-instar H. axyridis survival to adulthood was also significantly reduced by both neem formulations, while only azadirachtin reduced third-instar survivorship. Azadirachtin increased H. axyridis development time to adult when applied to both instars, while neem oil only increased time to adult when applied to first instar. Neither neem formulation affected the fecundity of either insect. Results are discussed within the context of future laboratory and field studies aimed at clarifying if neem-derived insecticides can be effectively integrated with biological control for soybean aphid management in organic soybeans.

English

&nbsp; Treatment and comparative analysis of the properties of aqueous extracts of seed kernel of&nbsp;Azadirachta indica&nbsp;A. Juss (neem) was carried out on&nbsp;Aedes aegypti&nbsp;larvae.&nbsp;The aim of this work was to evaluate lethal effects of neem products (1% Suneem, formulated neem oil and neem powder) on&nbsp;A. aegypti&nbsp;larvae. Assays showed that&nbsp;A. indica&nbsp;was toxic to larvae of&nbsp;A. aegypti. For 1% Suneem, 1% formulated neem oil andneem powder,&nbsp;the lethal concentrations and lethal time at 50% (LC50&nbsp;and LT50) for&nbsp;A. aegypti&nbsp;were 2 and 8 mg/l after 24 h and&nbsp;3 mg/l after 120 h,&nbsp;respectively.&nbsp;Assays showed that Suneem and Formulated neem oil were more toxic to&nbsp;A. aegypti&nbsp;than Neem powder.&nbsp;Both products of the neem (A. indica, A. juss) have a remarkable influence&nbsp;on the development of&nbsp;A. aegypti&nbsp;larvae, causing an inhibition of nymphs and adults emergency. The Histopathological results revealed a serious damage on the epithelial columnar cells, a perturbation of alimentary flow, slightly hypertrophied cells, a beginning of vacuolisation on apical level, and a bursting of some cells in posterior part of the gut. However, nuclei, adipose tissue and muscles seem to keep normal appearance. &nbsp; Key words:&nbsp;Azadirachta indica&nbsp;(neem),&nbsp;Aedes aegypti&nbsp;(mosquito), LC50, emergency, histopathology.

Effects of Neem Leaf Dust and a Commercial Formulation of a Neem Compound on the Longevity, Fecundity and Ovarian Development of the Melon Fly, Bactrocera cucurbitae (Coquillett) and the Oriental Fruit Fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae)

Neem leaf dust and a commercial formulation of neem were tested on adult Bactrocera cucurbitae (Coquillett) and Bactrocera dorsalis (Hendel) to determine their effects on the longevity, fecundity and ovarian development. Different combinations of neem leaf dust and a commercial formulation of a neem compound incorporated with sugar solution and adult rearing diets were tested. The Laboratory tests showed that ingestion of neem can significantly reduced the longevity and fertility of both the fly species. Significantly fewer pupae were collected from adults fed on laboratory rearing diet and nimbicidine as water source. Effect of neem treatment on the pupation and subsequent adult emergence of late-instar larvae was negligible. Microscopic observation indicated that the decreased fecundity was due to the block of ovarian development. Experimental results confirmed that neem can be effectively used as a safe alternative insecticide for the control of Bactrocera species.

The potential of combining Pasteuria penetrans and neem (Azadirachta indica) formulations as a management system for root-knot nematodes on tomato

Initial applications of 104 spores g−1 of Pasteuria penetrans, and dried neem cake and leaves at 3 and 2% w:w, respectively, were applied to soil in pots. Juveniles of Meloidogyne javanica were added immediately to the pots (500, 5,000 or 10,000) before planting 6-week-old tomato seedlings. The tomatoes were sampled after 64 days; subsequently a second crop was grown for 59 days and a third crop for 67 days without further applications of P. penetrans and neem. There was significantly less root-galling in the P. penetrans combined with neem cake treatment at the end of the third crop and this treatment also had the greatest effect on the growth of the tomato plants. At the end of the third crop, 30% of the females were infected with P. penetrans in those treatments where spores had been applied at the start of the experiment. The effects of neem leaves and neem cake on the nematode population did not persist through the crop sequences but the potential for combining the amendments with a biological control agent such as P. penetrans is worthy of further evaluation.

Toxicity of biopesticides and synthetic insecticides to egg parasitoid, Trichogramma chilonis Ishii, and coccinellid predator, Cheilomenes sexmaculata (Fabricius).

Toxicity of biopesticides and synthetic insecticides was assayed for egg parasitoid, Trichogramma chilonis Ishii and coccinellid predator, Cheilomenes sexmaculata ( Fabrieius) under laboratory conditions. Neem seed kernel extract (NSKE 5%), custard apple seed extract (CASE 5%), pongamia seed extract (PSE 5%), neem oil (2%) and pongamia oil (2%) were compared with commercial neem formulation (0.2%) for their toxic effect Synthetic insecticides like imidacloprid (0.01%), acetamiprid (0.002%), thiomethoxam (0.02%), profenophos (0.05%), and carbosulfan (0.14%) were compared with monocrotophos (0.05%) for their toxicity to T. chilonis and C. sexmaculata . Most of the botanicals were found safe to T. chilonis and C. sexmaculata . Among six insecticides tested, carbosulfan was found to be highly toxic to T. chilonis and C. sexmaculata , followed by acetamiprid. imidacloprid was relatively less toxic to botb species. Microbial biopesticide, Bacillus thuringiensis (Bt) was also found safe to both species.

Efficacy of neem ( Azadirachta indica) formulations on biology of root-knot nematodes ( Meloidogyne javanica) on tomato

Second stage juveniles of Meloidogyne javanica were exposed to aqueous extracts of neem crude formulations (leaves and cake) at 10%, 5%, and 2.5% w/v and a refined product, Aza at 0.1% w/v. The 10% extracts of neem leaf and cake caused 83% and 85% immobility and 35% and 28% mortality, respectively. Aza caused neither immobility or mortality of juveniles. When egg masses were placed in extracts of these formulations, hatching did not occur at all the concentrations (10%, 5%, 2.5% and 1.25% w/v) of the crude formulations. When the treated egg masses were returned to water, the eggs resumed hatching. Aza did not affect the nematode hatching. In glasshouse experiments, soil application of neem formulations significantly reduced the invasion of tomato roots by root-knot nematodes but once the nematodes managed to invade them, no effect detected on their development. Soil applications of Aza at 0.05% and 0.1% w/v significantly reduced the invasion and delayed development of nematodes within tomato roots whereas 0.025% did not. There were significantly fewer egg masses on tomato roots exposed to single egg mass in neem amended soil as compared to control.

Development and Evaluation of Thin-Layer Chromatography-Digital Image-Based Analysis for the Quantitation of the Botanical Pesticide Azadirachtin in Agricultural Matrixes and Commercial Formulations: Comparison with ELISA

A simple thin-layer chromatography-digital image-based analytical method has been developed for the quantitation of the botanical pesticide, azadirachtin. The method was validated by analyzing azadirachtin in the spiked food matrixes and processed commercial pesticide formulations, using acidified vanillin reagent as a postchromatographic derivatizing agent. The separated azadirachtin was clearly identified as a green spot. The Rf value was found to be 0.55, which was similar to that of a reference standard. A standard calibration plot was established using a reference standard, based on the linear regression analysis [r2 = 0.996; y = 371.43 + (634.82)x]. The sensitivity of the method was found to be 0.875 microg azadirachtin. Spiking studies conducted at the 1 ppm (microg/g) level in various agricultural matrixes, such as brinjal, tomato, coffee, and cotton seeds, revealed the recoveries of azadirachtin in the range of 67-92%. Azadirachtin content of commercial neem formulations analyzed by the method was in the range of 190-1825 ppm (microg/mL). Further, the present method was compared with an immunoanalytical method enzyme-linked immonosorbent assay developed earlier in our laboratory. Statistical comparison of the 2 methods, using Fischer's F-test, indicated no significant difference in variance, suggesting that both methods are comparable.

Farmer Participatory Evaluation of the Potential for Organic Vegetable Production in the Wetlands of Zambia

Although wetlands (locally called dambos) are considered extremely vulnerable to poor agricultural practices, rising population pressures have caused their agricultural use to become increasingly important. Intensification of dambo use by way of chemical fertilizer and pesticide applications poses serious challenges to their ecological sustainability. This study evaluated gliricidia (Gliricidia sepium) leafy biomass as a possible alternative to commercial fertilizer, and Tephrosia (Tephrosia vogelii) leaf extract, commercial formulations of neem seed extract (Achook) and Bacillus thuringiensis (Thuricide) as alternatives to chemical pesticides in the production of cabbage in dambos. The study showed that soil fertility management practices can significantly influence the time to harvest the cabbage crop and its yield. Vegetables grown using gliricidia biomass produced significantly higher yields compared with the no-input option. The population density of diamondback moth (Plutella xylostella) larvae, the percentage of plants infested by cabbage webworm (Hellula undalis) and cabbage aphid (Brevocoryne brassicae) was significantly lower in cabbage treated with sprays of Tephrosia leaf extract and Achook. It is concluded that gliricidia leafy biomass as a soil fertility management practice combined with Tephrosia leaf extract and neem seed extract as a crop protection practice could increase the productivity of cabbage and ensure sustainable utilization of dambos.

Residues and Persistence of Neem Formulations on Strawberry after Field Treatment

Azadirachtoids were determined by liquid chromatography/mass spectrometry (LC/MS) in five methanolic seed extracts of the neem tree and in a commercial formulation. On average, seed extracts contain azadirachtin A (10.9%), azadirachtin B (3.5%), nimbin (10.4%), and large quantities of salannin (19.0%). The composition of the commercial formulations may present different azadirachtoids contents depending on the natural extracts used in the preparation. Because these compounds may also show insecticide activity, the efficacy on field of these formulations may be very different. Photodegradation of pure azadirachtoids was also studied. Azadirachtins and related compounds are very sensitive to sunlight, degrading rapidly, with half-lives of the order of 11.3 h for azadirachtin A and 5.5 h for azadirachtin B and few minutes for the other limonoids compounds studied. The residues of azadirachtins and the main constituents, e.g., salannin, nimbin, deacetylnimbin, and deacetylsalannin, of the neem seed extract were determined on strawberries after field treatment using two different formulations. This residue study on strawberry was carried out to assess not only the azadirachtin content but also the main azadirachtoids contents. Three days after field application at five times the dose recommended by the manufacturer, residues of azadirachtin A and B were 0.03 and 0.01 mg/kg, respectively, while residues of salannin (LOQ 0.01 mg/kg) and nimbin (LOQ 0.5 mg/kg) were not detectable.

Systemic and persistent effect of neem ( Azadirachta indica) formulations against root-knot nematodes, Meloidogyne javanica and their storage life

Neem leaves, neem cake (a by-product left after the extraction of oil from neem seed) and a commercially refined product aza (azadirachtin) extracted from seed were evaluated. Aqueous extracts of crude neem formulations used as a seedling dip treatment significantly reduced the number of females and egg masses in roots whereas the refined one did not. A split-root technique was used to demonstrate the translocation of active compounds within a plant and their subsequent effect on the development of nematodes. When applied to the root portion all formulations significantly reduced the number of egg masses and eggs per egg mass. Whereas on the un-treated root portion, neem cake at 3% w/w and aza at 0.1% w/w significantly reduced the number of egg masses as compared with neem leaves at 3% w/w, aza at 0.05% and control. All the neem formulations significantly reduced the number of eggs per egg mass on the un-treated root portion. The effect of neem leaves and cake on the development of root-knot nematodes was tested at 2, 4, 6, 8, and 16 weeks after their application to soil. Even after 16 weeks all the treatments significantly reduced the galling index and number of egg masses but their effectiveness declined over time. After storing neem leaves, cake and aza for 8 months under ambient conditions the efficacy of neem leaves and aza, against root-knot nematodes, remained stable whereas that of cake declined.

Toxicidade de formulações de nim (Azadirachta indica A. Juss.) ao ácaro-rajado e a Euseius alatus De Leon e Phytoseiulus macropilis (Banks) (Acari: Phytoseiidae)

The toxicity of selected commercial formulations of neem on Tetranychus urticae Koch (Acari: Tetranychidae) and two predatory mites Euseius alatus De Leon and Phytoseiulus macropilis (Banks) was studied. Topical toxicity was tested with the commercial formulations (Natuneem, Neemseto and Callneem) and extract of neem's seeds at concentration 1%, compared to the standard acaricide abamectin at concentration of 0.3 ml/L and the control treatment (distilled water). Based on the best performance against T. urticae through topical contact, the formulation Neemseto was selected to be evaluated using different concentrations against eggs, and residual and repellent effects on adults of the mites. Egg treatment consisted of dipping eggs into Neemseto dilutions and control treatment for five seconds. In addition, residual and repellent effects of Neemseto for adult mites consisted of using leaf discs dipped into the dilutions for five seconds. The toxicity of Neemseto on eggs and adults was greater for T. urticae compared to the toxicity observed for the predatory mites. Neemseto was repellent for T. urticae and E. alatus when tested at the concentrations of 0.25, 0.50 and 1.0%, and did not affect P. macropilis. Neemseto using all concentrations, while for the predatory mites significant reduction of mite fecundity was only observed at the largest concentrations reduced the fecundity of T. urticae significantly. So Neemseto, among tested neem formulations, performed better against the twospotted spider mite and exhibited relatively low impact against the predatory mites studied.

Protective and curative effect of neem ( Azadirachta indica) formulations on the development of root-knot nematode Meloidogyne javanica in roots of tomato plants

Two types of neem formulations, crude and refined, were tested. The crude form was neem leaves and neem cakes (a by-product left after the extraction of oil from neem seed) and one of the neem-refined products was “aza”. The protective and curative soil application of these formulations significantly reduced the number of egg masses and eggs per egg mass on tomato roots. Protective application of neem crude formulations (leaves and cake) did not reduce the invasion of juveniles whereas aza at 0.1% w/w did. Curative application of neem formulations significantly reduced the number of egg masses and eggs per egg mass as compared with the control.

Varying effects of two lots of the botanical insecticide Neemix® 4.5 on immature survival and adult oviposition behavior of the diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae)

Variability in the insecticidal effects of botanical preparations has been one of the major obstacles in the application of this type of insecticide. Understanding of the variability may help to improve formulations of the preparations and develop more practical strategies for field applications. Here we report the varying effects of two lots of the same commercial neem formulation, Neemix® 4.5, on the diamondback moth, Plutella xylostella L. We found that one lot had stronger adverse effect on the development and survival of P. xylostella larvae but little repellent effect on the adults, whereas, the other lot had a weaker effect on the larvae but a substantial repellent effect on the adults.

Control of the house dust mite, Dermatophagoides farinae, by neem seed extracts

RATIONALE: For house dust mite control, most of the presently used acaricides are based on benzyl benzoate. This and other synthetics are under critical observation due to side effects. As an alternative, formulations based on neem (margosa) oil are available as OTC products in Europe. Seven of these products have been tested for their effect on house dust mites. METHODS: Following the ISO guide line, ANFOR NFG39-011, the neem oil derived products were tested for their effect against a mixed culture of D. farinae mites/eggs for 14 weeks. RESULTS: Starting with 200 mites and 50 eggs each, control reached an average level of 3.550 mites after 14 weeks. All the neem oil containing preparations showed no acaricidal effect. There was a clear difference in their inhibitory activity, however. Only two of them, TN-MP100® and Milbiol®, were able to inhibit growth and reproduction down to an insignificant level of about 100 mites after 14 weeks. All the other five products also significantly reduced growth and reproduction of the house dust mite, but only in the range of two thousand to 500 mites. CONCLUSIONS: TN-MP100® and Milbiol® are highly effective and safe neem formulations for the control of the house dust mite and consequently of house dust allergy. The results clearly demonstrate the high effect of the two neem based products against the allergens producing house dust mite.