Effectiveness of Neem Leaf Extract And Packaging Types On The Quality of Cilembu Variety Sweet Potato

Evaluation of the immuno-stimulatory effect of aqueous neem (Azadirachta indica) leaf extract against highly pathogenic avian influenza (H5N8) in experimental chickens

In recent times, the biosynthesis of nanoparticles, which has led to significant growth in the field of nanotechnology. The use of plant extracts has become an impetus in this field as it is a simple and eco-friendly method. This study was an attempt to study different parameters in biosynthesis of silver nanoparticles using Azadirachta indica (Neem) leaf extracts. Four different process parameters such as concentrations of neem leaf extract, types of neem leaf extract, mixing ratios and the reaction time period were investigated on the formation of silver nanoparticles. Initially, the formation of silver nanoparticles was detected by the visual observation. Then, the synthesized silver nanoparticles were characterized using UV-Visible spectroscopy and scanning electron microscopy (SEM). The change of color from yellow to reddish brown color confirmed the formation of silver nanoparticles. The silver surface plasmon resonance (SPR) band obtained in the expected visible range of UV-Visible spectroscopy confirmed the synthesis of the nanoparticles. SEM images showed that silver nanoparticles are roughly spherical and of uniform particle size, and the average particle size is 100 nm. Further, the maximum absorbance of SPR band was considerably varied with different process parameters used in the present study. The UV-Visible spectra of 2.5 g/100 mL of crude neem leaf extract without any dilution showed maximum absorbance in the expected range with the mixing ratio of (Neem and AgNO3) 1:8. However, the maximum absorbance of modified neem leaf extracts (pH 10) resulted lower in value than the crude extracts in the 20 times diluted sample with the mixing ratio of 1:9. Moreover, modified extract with UV radiation exposure increased the absorbance in the expected visible range. It concludes that fine tuning of the bioprocess parameters would enhance nanoparticle synthesis.

The study was carried out to minimize the postharvest loses and extend shelf life of mango fruitby maintaining physico-chemical properties. The variety selected for the study was “Amrapali”. Freshly harvested mango was treated with different concentrations (20% and 40%) of neem leaf and banana pulp extract alone or in combination. Untreated mango was considered as control. All treated and untreated mango was kept into paper cartons at room condition. The treated fruits showed significant differences in case of total soluble solids content, titratable acidity, vitamin C, disease incidence, disease severity and shelf life in comparison to control fruits. Among the treatments, T2 (neem leaf extract at 20%) and T5 (neem leaf extract 40% + banana pulp extract 40%) treatments showed longer shelf life (9.92 and 10.25 days, respectively), slower changes in color (score 2.77 and 2.93, respectively) and firmness (score 2.67 and 2.77, respectively); less disease severity (score 2.93 and 3.57, respectively), disease incidence (46.67% and 60.00%) and lower loss in weight (38.04% and 35.17%, respectively) at 9 DAT (Days after treatment). On the other hand, total soluble solid was highest in T3 (neem leaf extract 40%) treated fruitswith18.73% more Brix at 13 DAT in comparison to control and other treatments. The effectiveness of the treatment T5 (neem leaf extract 40% + banana pulp extract 40%) was meaningful which could be recommended for maintenance of postharvest quality of mango stored in ambient conditions.
 J. Bangladesh Agril. Univ. 16(3): 343–350, December 2018

An experiment was conducted at Akure, rainforest zone of Nigeria to evaluate theeffectiveness of neem leaf, wood ash extracts, modified neem leaf extract, Apron star 42WS andKarate 720EC as seed treatment and pest control in maize. The organic treatment extracts namelyneem leaf extract, wood ash extract applied at 1200ml per hectare and modified neem leaf extract(1:1 ratio 600ml wood ash + 600ml neem leaf extract) were compared with Apron star 42WS (seedtreatment), Karate 720EC and control treatment (no neem leaf, wood ash extracts nor Karate),replicated four times and arranged in randomized complete block design. The results showed thatthere were significant differences (P < 0.05) in the germination counts, insect population, numberof damaged leaves, growth and yield parameters of maize under different treatments compared tothe control treatment. The modified neem leaf extract performed better in germination counts,reduction of damaged leaves, insect population and yield of maize than the sole application ofneem leaf and wood ash. For percentage germination counts, Apron star 42WS had 65% followedby modified neem leaf extract (57%), wood ash extract (51%), neem leaf extract (47%)respectively. Modified neem leaf extract increased the leaf area, plant height and stem girth ofmaize by 8%, 5% and 7% respectively compared to the neem leaf (sole) extract. Generally,modified neem leaf extract had the best values of maize growth parameters followed by Karate,neem leaf and wood ash extracts respectively. Modified neem leaf extract decreased significantlythe insect population, number of damaged leaves and number of holes per plant in maize by 33%,70% and 30% respectively compared to the neem leaf extract (sole). When compared to modifiedneem extract, Karate decreased the number of damaged leaves per sample plot by 33%. However,there was no significant difference between karate and modified neem extract for insectpopulation. For yield parameters, modified neem leaf extract significantly increased the maizeyield gains by 15%, 14% and 2% compared to neem leaf, wood ash extracts and karate treatmentsrespectively. However, wood ash and neem leaf extracts did not affect significantly the maizeyield. Therefore, the modified neem leaf extract applied at 1200L/ha (3L/25m2) was mosteffective for pest control and seed treatment in maize crop.

This study was conducted to evaluate the acaricidal effect of Neem Tree Leaf Extract (Azadirachta indica) using varying levels of concentrations at different lengths of exposure and to compare its efficacy with Organophosphate. The Experiment was laid out in Completely Randomized Design (CRD) with five treatments, replicated three times. The treatments evaluated were as follows: T1 – Organophosphate (Control); T2 – 25% Neem Tree Leaf Extract; T3 – 50% Neem Tree Leaf Extract; T4 – 75% Neem Tree Leaf Extract; and T5 – 100% Neem Tree Leaf Extract. Filter papers were dipped with the extracts and matted in petridishes. The ticks were placed in the treated filter papers with corresponding levels of Neem Tree Leaf Extract. There were three observations (60, 90 and 120 minutes) used to determine the effect and the killing duration of the extract. All the levels of the Neem tree leaf extract concentration used could kill ticks of cattle, however, the killing depends upon the level of concentrations and the duration of exposure. At higher concentrations, it was proven that the killing effect of the Neem tree leaf extract to adult ticks were faster than the extract at lower concentration. Based on the result of the study, the use of Organophosphate (control) was statistically similar to that of 100 percent Neem tree leaf extract in killing ticks at a maximum length of one hundred twenty minutes exposure.

Aims: The present study aimed to synthesize silver nanoparticles using aqueous neem (Azadirachta indica) leaf extract, characterize them, and compare the larvicidal activity of the extract with that of the synthesized nanoparticles against Aedes aegypti larvae. Study Design: Following completely randomized designs (CRD) the experiment was conducted, in triplicates. Place and Duration of Study: Dept. of Aquatic Animal Health Management, at college of Fisheries, Kishanganj, between May 2023 and August 2024. Methodology: Neem leaves collected, processed, and by heating aqueous extracts was prepared, followed by adding extract to silver nitrate (1mM) the silver nanoparticles were prepared. The physicochemical characteristics of green synthesized AgNPs was analysed (UV-Vis spectra, Dynamic Light Scattering, TEM, SEM and Fourier Transform Infrared (FTIR) analysis at SAIF-IIT, Bombay). The mosquito larvae recovered from fish tank exposed to different concentrations of AgNPs and neem leaf extracts and based on mortality following Probit analysis median lethal concentration (LC50) was calculated. All the data were analysed using one way ANOVA, (Statistical tool-SPSS, version 22). Results: The biosynthesized AgNPs showed a maximum absorption peak at 420 nm, with a zeta potential of –45.5 mV. TEM and SEM analyses revealed spherical, monodispersed nanoparticles with an average size range of 5-50 nm, while FTIR analysis confirmed the presence of various functional groups conjugating with the AgNPs. Larvicidal bioassays demonstrated significantly higher mortality of A. aegypti larvae (p=0.05), achieving 100% mortality at a low concentration of 25 ppm within 96 h, compared to 1000 ppm for neem leaf extract. Mortality rates were also significantly higher at elevated AgNP concentrations compared to the control and other treatments. The estimated 96 h LC₅₀ values were 3.22 ppm for green-synthesized AgNPs and 381.94 ppm for aqueous neem leaf extract. Conclusion: AgNPs showed greater larvicidal efficacy than aqueous neem extract against A. aegypti larvae, suggesting their potential as an eco-friendly alternative to chemical controls, however, the safety validation of AgNPs under field conditions need to be studied thoroughly.

Simple SummaryCoccidiosis, one of the most contagious diseases among domestic rabbits, negatively affects production and results in massive economic losses. This study evaluates the therapeutic efficacy of treatment with aqueous neem leaf extract and ethanolic pomegranate peel extract (PPE) individually and in combination on the intestinal coccidiosis caused by Eimeria spp. in New Zealand white and V-line (VL) rabbits. Rabbits from two breeds were divided into ten equal groups (five groups each for NZ and VL). All rabbits were inoculated with Eimeria spp. oocysts except for the rabbits in the first group (G1) (negative control). The remaining groups were: G2, positive control, G3, treated with neem leaf extract, G4, treated with pomegranate peel extract (PPE), and G5, treated with a combination of neem leaf extract and PPE. Our results showed that the use of neem leaf and/or pomegranate peel extract for both breeds resulted in improved growth performance, a significant reduction in mean oocyst count, no mortalities, an anticoccidial index > 120, and significantly improved economic efficiency measures when compared to the positive control group.Healthy, weaned, coccidial-free male rabbits from two breeds (New Zealand white (NZ) and V-line (VL)) were divided into 10 equal groups (5 groups each for NZ and VL) (3 replicates/group, 6 rabbits/replicate, 18 rabbits/group). All rabbits were inoculated with 5 × 104 Eimeria spp. oocysts (E. intestinalis (67%), E. magna (22%), and E. media (11%)) except for the rabbits in the first group (G1), which were inoculated with a sterile solution and served as a negative control. The remaining four groups were treated as follows: G2, no treatment/positive control, G3, treated with neem leaf extract, G4, treated with pomegranate peel extract (PPE), and G5, treated with a combination of neem leaf extract and PPE. For both breeds, our results showed that the use of neem leaf and/or pomegranate peel extract resulted in improved growth performance, with a significant improvement in relative feed conversion ratio (FCR) compared to the positive control groups, which recorded the worst values, as well as a significant (p ≤ 0.05) reduction in mean oocyst count compared to the positive control groups. We also observed downregulation of mRNA levels of IL-1βα, IL6, and TNF-α in the herbal treatment groups compared with the mRNA levels of these genes in the positive control groups. Herbal treatment with neem leaf and/or pomegranate peel extracts had positive effects on the NZ and VL rabbits experimentally infected with mixed Eimeria species, as evidenced by their healthy appearance, good appetite, no mortalities, an anticoccidial index > 120, and a significantly higher total return and net profit when compared to the positive control groups of both breeds. In NZ rabbits, the treatment with neem leaf extract alone (G3) or in combination with PPE (G5) recorded the most efficient economic anticoccidial activity.

Aphids that attack red pepper plants cause yield loss. Applying neem leaf extract in the form of concentration and frequency of yield losses can be avoided. Neem leaf extract contains secondary metabolite compounds that can function as vegetable insecticides to suppress the level of aphid attacks on chili plants. Saponins, meliantriol, and azadirachtin have been known as active ingredients that act as insecticides with different mechanisms of action against aphids, such as saponins as stomach poisons and contact poisons, meliantriol as a repellent (repellent/repellent), and azadirachtin as an inhibitor of ecdysone hormones (hormones that play a role in the process of metamorphosis or molting or exoskeleton of aphids). The study aimed to determine the effect of concentration and frequency of neem leaf extract on the incidence and severity of chili aphid attacks as well as plant development. The proposed solution to overcome aphid attacks is administering neem leaf extract to red chili plants. The method uses a randomized trial design of factorial groups with two factors. The first factor is the concentration of neem leaf extract which consists of four levels, namely: S0 = 0% (100 ml of water or without neem leaf extract), S1 = 10% (10 ml of neem leaf extract + 90 ml of water), S2 = 30% (30 ml of neem leaf extract + 70 ml of water), and S3 = 50% (50 ml of neem leaf extract + 50 ml of water). The second factor is the frequency of giving neem leaf extract, which consists of four levels: M1 = age 8 HSPT, M2 = age 16 HSPT, M3 = age 24 HSPT, and M4 = age 32 HSPT. The findings of this study are that the frequency of giving neem leaf extract three times showed a real effect on the severity of aphid attacks at the age of 44 days after transplanting, and giving a 10% extract had a real effect on height, leaf area, number of flowers, header dry bobobt, and dry weight of chili plant roots. The results of this study conclude that the administration of neem leaf extract can suppress the severity of the attack of red chili plant aphids.

Active components of neem leaves and seeds were extracted with different methods in order to study the effect of different extract concentrations on the inhibition of some pathogenic fungi. High-performance liquid chromatography (HPLC) was used to identify the active components of neem extract. Highest inhibition percentage of ethanolic neem leaf extract was recorded with Rhizoctonia solani, while the lowest was recorded withAlternaria solani. A complete inhibition percentage was recorded with 40% ethanolic neem leaf extract of R. solani and Fusarium oxysporum. The highest inhibition percentages were recorded with F. oxysporum (10, 20, 30 and 40%) concentrations of hexane neem leaf extract, while the lowest was recorded with A. solani. The highest inhibition percentages were recorded with R. solani (10, 20 and 30%) concentrations of methanolic neem leaf extract, while the lowest was recorded with the same mentioned concentration of Sclerotinia sclerotiorum. A complete inhibition percentage was recorded with 40% methanolic neem leaf extract of F. oxysporum and R. solani, while the lowest was recorded with S. sclerotiorum. The highest inhibition percentage was recorded with R. solani (10 and 20%) concentrations of ethanolic neem leaf extract and the lowest was recorded with A. solani. The highest inhibition percentage was recorded with (10, 20, 30 and 40%) hexane neem seed extract of F. oxysporum. The lowest inhibition percentages with the same mentioned concentrations were recorded with A. solani. The highest inhibition percentage was recorded with (10 and 20%) methanolic neem seed extract of R. solani. The lowest inhibition percentage was recorded with S. sclerotiorum. The inhibition percentage of tested fungi increased by increasing neem leaf and seed extract by different rates. Also, neem seed organic extracts had higher inhibition percentage than that of neem leaf organic extracts. HPLC chromatogram of neem organic extract showed that nimonol (82%) is the major active component of neem organic extract. Key words: Neem, extraction, pathogenic fungi, High-performance liquid chromatography (HPLC).

The study was conducted to evaluate the antimicrobial activity of neem (Azadirachta indica) leaf extract against fungal phytopathogens isolated from diseased tomato (Lycopersicum esculentum) fruit. Diseased tomato fruits were obtained and to establish a mixed culture. Two distinctive fungi were identified on the mixed cultures and subculture into freshly prepared potato dextrose agar medium. The fungal isolates were identified using the cultural characterization. Neem (Azadirachta indica) leaves were obtained and used to prepare water extract. The antifungal activity of the neem leaf extract was evaluated using the poison plate method. Mycelial growth was measured and recorded. The results showed that two fungal pathogens were isolated from the diseased tomato fruit. The cultural characterization of the two isolates revealed the identity of the fungal isolates to be Diaporthe and Xylaria species. There was a significant reduction in the mycelia growth of Diaporthe species with values of 2.210±0.34, 1.42±0.37, and 0.61±0.16 cm for the 25, 50, and 100% neem leaf extract, respectively, compared to the control (3.67±0.34 cm), indicating antifungal activity of the neem leaf extract. Conversely, only the 25 and 50% neem extract showed antifungal activity against Xylaria species. The findings of the present study suggest that neem leaf extract could be used to preserve tomato fruits from fungal pathogens causing spoilage.

The present studies were conducted to investigate the effects of different concentration of neem leaf extract (NLE) (control, 10%, 20% and 30%) on physiological, biochemical, antioxidant properties, and fruit quality attributes of Shamber grapefruit during cold storage at 10 °C up to 43 days. Weight loss, peel weight, juice weight, rag weight, ascorbic acid, total sugars (TS), reducing sugars (RS), non-reducing sugars (NRS), total soluble solids (TSS), titratable acidity (TA), TSS/TA ratio and enzyme activities such as superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) were determined. NLE treatments showed significant effect on postharvest quality attributes of Shamber grapefruit. NLE-treated grapefruit (30%) reduced the weight loss (16%), and retained maximum peel weight (9.02%), juice weight (25.56%) and rag weight (19.21%) than untreated control fruit. Moreover, high level of ascorbic acid, TSS, TA, and lower level of TS, RS and NRS were observed in NLE (30%) treated fruits. Enzymatic activities of SOD, POD and CAT of stored grapefruit were highly significant in NLE (30%) treated grapefruit during storage period compared to control. In conclusion, pre-storage NLE (30%) application was the most effective in maintaining various physiochemical properties such as weight loss, ascorbic acid, TS, RS, NRS, TSS, TA, TSS:TA ratio and increasing the antioxidative responses (SOD, POD and CAT) up to 43 days by extending the shelf life of Shamber grapefruit.

Mulching with plastic film improved the root quality of summer-sown sweet potato (Ipomoea batatas (L). Lam.) in northern China

In separate treatments, a spore suspension ofA. flavus (control), an aqueous leaf extract of the subtropical neem tree plus a spore suspension ofA. flavus, or an aqueous neem leaf extract followed by anA. flavus spore suspension were injected 48 hr later onto the surfaces of locks of developing cotton bolls (30‐day post anthesis). Thirteen days after the treatments, the seeds from the locules were harvested and both fungal growth and aflatoxin production were determined. Fungal growth was unaffected by the treatments but the seeds from locules receiving both neem leaf extracts andA. flavus simultaneously exhibited 16% inhibition of aflatoxin production, while the seeds in locules receivingA. flavus spores 48 hr after neem extract was added exhibited &gt;98% inhibition in aflatoxin production. Neem leaf extracts contain an aflatoxin inhibiting factor, however, the neem leaf extract may need to translocate from the fibrous locule surface to the seed, prior to the fungal inoculation, for maximal effect.

Groundnut (Arachis hypogaea L.), one of the most important oilseed crops grown across tropical and subtropical regions, faces a serious threat from stem rot disease. This disease is caused by a soil-borne fungus called Sclerotium rolfsii, which can severely impact plant health and reduce yields. The present study was carried out to evaluate the efficacy of combination of bioagent and neem oil as biocontrol strategies in managing stem rot. The experiment was conducted in a Randomized Block Design (RBD) with seven treatments and three replications. Among seven treatments disease incidence (%) at 60, 75 and 90 days after sowing recorded minimum in treatment T1- Trichoderma harzianum (S.T) + Neem leaf extract @10% (F.S) (11.11%), (17.67%) and (17.77%), followed by T5- Trichoderma asperellum (S.T) + Neem leaf extract @10% (F.S) (13.33%), (22.23%) and (24.44%) and least in T3- Trichoderma reesei (S.T) + Neem leaf extract @10% (F.S) (44.44%), (30.00%) and (44.44%) respectively.

Aim:The present study was conducted to evaluate the effects of neem leaf extract (NLE) supplementation on immunological response and pathology of different lymphoid organs in experimentally Escherichia coli challenged broiler chickens.Materials and Methods:For this study, we procured 192-day-old broiler chicks from local hatchery and divided them into Groups A and Group B containing 96 birds each on the first day. Chicks of Group A were supplemented with 10% NLE in water, whereas chicks of Group B were not supplemented with NLE throughout the experiment. At 7th day of age, chicks of Group A were divided into A1 and A2 and Group B into B1 and B2 with 54 and 42 chicks, respectively, and chicks of Groups A1 and B1 were injected with E. coli O78 at 107 colony-forming units/0.5 ml intraperitoneally. Six chicks from each group were sacrificed at 0, 2, 4, 7, 14, 21, and 28 days post infection; blood was collected and thorough post-mortem examination was conducted. Tissue pieces of spleen and bursa of Fabricius were collected in 10% buffered formalin for histopathological examination. Serum was separated for immunological studies.Result:E. coli specific antibody titer was significantly higher in Group A1 in comparison to Group B1. Delayed-type hypersensitivity response against 2,4 dinirochlorobenzene (DNCB) antigen was significantly higher in Group A1 as compared to Group B1. Pathological studies revealed that E. coli infection caused depletion of lymphocytes in bursa of Fabricius and spleen. Severity of lesions in Group A1 was significantly lower in comparison to Group B1.Conclusion:10% NLE supplementation enhanced the humoral as well as cellular immune responses attributed to its immunomodulatory property in experimentally E. coli infected broiler chicken.