Evaluation of colemanite as a slow release source of boron fertilizer for potato

Aim: The present study was conducted with an objective to assess the suitability of colemanite (Ca2 B6.O11.5H2O) as a slow release source of boron to potato crop. Methodology: Soil was incubated with boron (1.25 and 2.50 mg kg-1 soil) using borax and colemanite for six weeks. Soil moisture was maintained at 80% field capacity. Soil samples were analyzed weekly for hot-water extractable boron content. Direct and residual effects of borax and colemanite on potato plant growth and boron uptake were studied in pot experiments. Leaf boron concentration was measured by an ICP-OES. Results: In laboratory incubation, although the rate of release of hot water extractable boron from colemanite was slower than borax, it was enough to meet the requirement of potato crop. Application of both the sources of boron increased its content significantly in soil as well as in potato leaves. This study revealed that boron uptake from colemanite was comparable to borax in meeting the boron requirement of potato. Interpretation: Soil incubation and pot experiment studies showed that colemanite is a suitable slow release source of boron fertilizer for potatoes

Investigation of the antimicrobial, antioxidant and anti-inflammatory activity of compound isolated from murraya koenigii.

In the present investigation, the compound responsible for antioxidant, antimicrobial and anti-inflammatory properties in methanolic extract of leaves of Murraya koenigii L. was determined by Perkin- Elmer GC Claurus 500 system and Gas Chromatograph interfaced to a Mass Spectrometer GC/MS technique. GC-MS analysis of methanol extract of the leaves of the plant revealed the existence of 1- Methyl-pyrrolidine-2-carboxylic acid (69.00%), Ethyl α-d glucopyranoside (13.36%), Isolongifolene, Isolongifolene (3.68%), c-Himachalene (2.88%), 1,2-Ethanediol, monoacetate (2.79%), 1,2- Benzenedicarboxylic acid, di-isooctyl ester (2.55%). The pure compounds were separated using a Shimadzo LC 2010 HPLC system (Kyoto, Japan), equipped with a Shimadzo LC 2010 UV-VIS detector with a thermostated flow cell and a selectable two wavelengths of 190 - 370 nm or 371–600nm. These were further screened for their antimicrobial, antioxidant and anti-inflammatory properties. All the compounds possessed some or the other activity. It was found that the compound 9, 12 octadecadienoic acid having the retention time 18.81 and the peak area 0.60 % had potent antioxidant, antimicrobial and anti-inflammatory properties. The compound showed potent antimicrobial activity against Bacillus subtilis, E.coli, Proteus vulgaris, Salmonella typhimurium, Staphylococcus aureus, Candida albicans, Saccharomyces cerevisae, Aspergillus niger and Penicillium notatum at MIC value from 0.05-0.56 μg/ml. The compound showed less activity against Pseudomonas aeruginosa in comparison to other pathogens. The compound possessed to have strong antioxidant activity with IC50 value of 45.65 μg/ml as measured by DPPH assay. The compound possessed 85 % reduction in paw edema at a dose of 150 μg/ml in reference to standard anti-inflammatory drug, aspirin which showed 68.62 % reduction. The compound was further assayed for cellular toxicity to fresh sheep erythrocytes and found to have no cellular toxicity.

Toxicological properties of several medicinal plants from the Himalayas (India) against vectors of malaria, filariasis and dengue

The leaves of five plants namely Nyctanthes arbortistis (Oleaceae), Catharanthus roseus (Apocynaceae), Boenininghusenia albiflora (Rutaceae), Valeriana hardwickii (Valerianaceae) and Eupatorium odoratum (Asteraceae) were selected for the first time from the Garhwal region of north west Himalaya to investigation its toxicological properties against mosquito vectors of malaria, filariasis and dengue. In a laboratory study, using different polarity solvents (petroleum ether, chloroform and methanol) were tested against important larvae of malaria, filariasis and dengue vectors in India. It was observed that petroleum ether fraction of all selected plant possess good larvicidal properties than other solvent fraction. The LC50 values of isolates from Nyctanthes arbortistis (HAR-1), C. roseus (CAT-1), B. albiflora (BOA-1), V. hardwickii (SUG-1) and E. odoratum (EUP-1) against Anopheles stephensi were 185 ppm, 150 ppm, 105 ppm, 225 ppm and 135 ppm, respectively. The results therefore suggest that the fraction code BOA-1 has excellent larvicidal properties and could be incorporated as botanical insecticides against mosquito vectors with high safety to nontarget organisms. The same fraction was tested against adult vectors of malaria, filariasis and dengue, but no mortality was observed.

Community awareness, perceptions, acceptability and preferences for using LLIN against malaria in villages of Uttar Pradesh, India.

Background & Objectives: Long-lasting insecticidal nets (LLINs) have been introduced in India recently into the vector control programme. A study was undertaken to assess the community perception regarding use of LLIN, their acceptability, collateral benefits, etc. in certain villages of District Gautam Budh Nagar, Uttar Pradesh, India where LLINs are in use by the community. Method: A randomized community-based survey was undertaken during April–May 2009 covering 596 respondents in LLIN villages where LLINs have been distributed along with 307 respondents in untreated net villages where untreated nets were distributed using structured questionnaire. Qualitative data were collected and the difference in proportion was calculated by z-test. Results: A substantial number of respondents had good knowledge of the symptoms of malaria. According to respondents, LLINs were very much effective in bringing down the malaria incidence in their families. About 98.3% of the respondents asserted the use of LLINs as their use not only reduced the number of mosquitoes as well as other non-target insects, but also reduced the malaria incidence. About 93.2% of the respondents were ready to purchase LLINs if available at nominal prices. All the respondents were satisfied about the performance of the LLINs in reducing the mosquito nuisance, safety of use and collateral benefits in LLIN villages. Conclusion: LLINs are safe, socially acceptable and should be promoted for vector control to reduce the disease burden in the communities.

Adulticidal activity of essential oil of Lantana camara leaves against mosquitoes.

Background & objectives: Development of insect resistance to synthetic pesticides, high operational cost and environmental pollution have created the need for developing alternative approaches to control vector-borne diseases. In the present study we have investigated the insecticidal activity of essential oil isolated from the leaves of Lantana camara against mosquito vectors. Methods: Essential oil was isolated from the leaves of L. camara using hydro-distillation method. Bioassay test was carried out by WHO method for determination of adulticidal activity against mosquitoes. Different compounds were identified by gas chromatography-mass spectrometry analysis. Results: LD50 values of the oil were 0.06, 0.05, 0.05, 0.05 and 0.06 mg/cm2 while LD90 values were 0.10, 0.10, 0.09, 0.09 and 0.10 mg/cm2 against Ae. aegypti, Cx. quinquefasciatus, An. culicifacies, An. fluvialitis and An. stephensi respectively. KDT50 of the oil were 20, 18, 15, 12, and 14 min and KDT90 values were 35, 28 25, 18, 23 min against Ae. aegypti, Cx. quinquefasciatus, An. culicifacies, An. fluviatilis and An. stephensi, respectively on 0.208 mg/cm2 impregnated paper. Studies on persistence of essential oil of L. camara on impregnated paper revealed that it has more adulticidal activity for longer period at low storage temperature. Gas chromatographic-mass spectrometric analysis of essential oil showed 45 peaks. Caryophyllene (16.37%), eucalyptol (10.75%), α-humelene (8.22%) and germacrene (7.41%) were present in major amounts and contributed 42.75 per cent of the total constituents. Interpretation &conclusion: Essential oil from the leaves of L. camara possesses adulticidal activity against different mosquito species that could be utilized for development of oil-based insecticide as supplementary to synthetic insecticides.

Evaluation of Larvicidal and Repellent Activity of Xanthium Strumarium (Asteraceae) Ethanol Extract agaist Mosquito Vectors.

Ethanol extract of leaf and seed of Xanthium strumarium was investigated for anti-mosquito potential, including larvicidal and repellent activities against Anopheles culicifacies, Anopheles stephensi, Culex quinquefasciatus and Aedes aegypti. The ethanol-extracted Xanthium strumarium possessed larvicidal activity against fourth instar larvae of An. culicifacies, An. stephensi Cx. quinquefasciatus and Ae. aegypti. The LD 50 and LD values of ethanol-extracted of leaf were 0.19, 0.8, 0.27, 0.27% and 90 1.3, 1.3, 1.0, 1.8% and seed were 0.15, 0.9, 0.25, 0.23 and 1.5, 1.4, 1.7, 1.9% against An. culicifacies An. stephensi Cx. quinquefasciatus and Ae. aegypti respectively. It showed 100% repellency against An. culicifacies, An. stephensi and Culex quinquefasciatus in 0h 1h, 2h 4h and 1h 2h 6h, at 10% concentration respectively. It also provided biting protection time of 0h, 1h, 2h, 4h, and 6h when applied at a concentration of 2.5, 5, and 10 %. Against Deet- 2.5% An. culicifacies Giles species A 100% repellency in 1h, 2h, An. stephensi Liston 100% repellency in 2h, 4h, and Culex quinquefasciatus Say have shown 100% repellency in 4h. Xanthium strumarium, therefore, can be considered as a probable source of some biologically active compounds used in the development of mosquito control agents, particularly repellent and larvicidal products.

Investigation of malaria prevalence at National Thermal Power Corporation, Shaktinagar, Sonbhadra District (Uttar Pradesh), India.

Malaria in industrial complexes is promoted by extensive mosquitogenic potential generated by excavations and importation of parasite through migratory labor. The National Thermal Power Corporation (NTPC), Shaktinagar, Sonbhadra district was surveyed for malariogenic conditions from 1994 to 1996. The major mosquito breeding sites were drains, storm-water drains, lakes, outside tanks, overhead tanks, sluice-valve chambers, ornamental tanks, wells, pit wells and water reservoirs, etc. Anopheles culicifacies was the major vector of malaria in this area. Sibling species identification of An. culicifacies revealed that species C predominated during the transmission season and responsible to transmit malaria. Insecticide susceptibility tests against An. culicifacies sl showed that An.culicifacies population was 100% susceptible to malathion, fenitrothorn and deltamethrin while it was found 44% resistant to DDT. The malaria cases recorded in 1994, 1995 and 1996 were 847, 590 and 409 respectively. In vitro study on P. falciparum cases showed that 41, 70, 50% of the isolates tested were resistant to chloroquine in 1994, 1995 and 1996 respectively while an in vivo follow-up study showed 20-30% P. falciparum cases resistant to chloroquine. An integrated approach involving alternate vector control measures along with judicious use of insecticides has been suggested to bring down malaria in industrial complexes.

Chloroquine concentration profile in the community of Mewat region, district Gurgaon (Haryana), India.

A survey was conducted to find chloroquine concentration profile in the community of Mewat region district Gurgaon (Haryana) of India. 88 P. falciparum and 3 P. vivax cases were detected out of 148 blood slides examined with a SPR of 61.48. Plasma chloroquine and desethylchloroquine concentrations were determined in 55 P. falciparum and 2 P. vivax patients and 29 persons whose blood slides were negative for malaria parasite before giving any treatment. Mean chloroquine concentrations in cases with P. falciparum parasites and without malaria parasites were 0.018 and 0.016 microg ml(-1) respectively. Chloroquine to desethyl chloroquine ratio was between 2 and 3 in both groups. Only 10 malaria parasite negative cases out of 29 had plasma chloroquine concentrations above 0.016 microg ml(-1) required for malaria chemoprophylaxis. Chloroquine was undetectable in plasma samples of 8 out of 55 P. falciparum cases. Chloroquine plasma concentrations in 21 P. falciparum cases were below therapeutically effective concentration of 0.016 microg ml(-1) suggesting improper treatment while in 29 P. falciparum cases, parasitemia recurred despite required chloroquine concentration confirming chloroquine resistant status. Irregular prophylaxis and lack of proper treatment was one of the major causes of malaria outbreak in this area.

Field studies on the mosquito repellent action of neem oil.

Repellent action of neem oil was evaluated against different mosquito species. 2% neem oil mixed in coconut oil provided 96-100% protection from anophelines, 85% from Aedes, 37.5% from Armigeres whereas it showed wide range of efficacy from 61-94% against Culex spp. Therefore, neem oil can be applied as a personal protection measure against mosquito bites.