Sherene T.,Tamil Nadu Agricultural University
Research Journal of Chemistry and Environment | Year: 2012
A survey work was undertaken to assess the concentration of heavy metal pollution in soils of Coimbatore district. Totally three hundred and eight surface (0-15 cm) soil samples were collected around the industrial areas by using auger. Among the different industrial areas, electro plating and sewage water irrigated areas fell in excess tolerable category for Pb and Ni. As per SPI scale, the soils collected in the vicinity of electro plating, textile, casting and sewage water irrigated fields seemed to be dangerously polluted with toxic Pb, Ni, Cd, Cr, Cu and Zn. The delineation of Pb and Ni contaminated sites of Coimbatore district was done using SURFER software package. Therefore, there is a possibility of silent epidemic of environmental metal poisoning from the ever-increasing amount of metals wasted into biosphere.
Maski D.,Iowa State University |
Durairaj D.,Tamil Nadu Agricultural University
Journal of Electrostatics | Year: 2010
Combinations of electrode voltage, liquid flow rate, and properties can enhance chargeability of electrostatic sprays for effective pesticide application, though the combined effects of these parameters are not well understood. Generally, 4 kV voltage and lower (30, 45, and 60 mL min-1) flow rate of tank water produced greater chargeability compared to ground water sprays. The rate of increase in spray chargeability with decreased liquid flow rate was higher in the lower flow rates. The outcome of the study will be helpful for the more targeted and environmentally safe application of pesticide sprays and development of suitable electrostatic spraying systems.
Kasirajan S.,Tamil Nadu Agricultural University |
Ngouajio M.,Michigan State University
Agronomy for Sustainable Development | Year: 2012
The use of plastic mulch in agriculture has increased dramatically in the last 10 years throughout the world. This increase is due to benefits such as increase in soil temperature, reduced weed pressure, moisture conservation, reduction of certain insect pests, higher crop yields, and more efficient use of soil nutrients. However, disposing of used plastic films, which cause pollution, has led to development of photodegradable and biodegradable mulches. Here we review the use of plastic mulches in agriculture, with special reference to biodegradable mulches. Major topics discussed are (1) history of plastic mulch and impact on crop yield and pest management, (2) limitations of polyethylene mulches and potential alternatives, (3) biodegradable and photodegradable plastic mulches, (4) field performance of biodegradable mulches, and (5) use of biodegradable plastic mulches in organic production. We found that (1) despite multiple benefits, removal and disposal of conventional polyethylene mulches remains a major agronomic, economic, and environmental constraint; (2) early use of photodegradable plastic mulch during the 1970s and 1980s, wrongly named biodegradable mulch films, discouraged adoption of new biodegradable mulch films because they were too expensive and their breakdown was unpredictable; (3) biodegradable plastic films are converted through microbial activity in the soil to carbon dioxide, water, and natural substances; (4) polymers such as poly(lactic acid), poly(butylene adipatecoterephthalate), poly(?-caprolactone), and starch-based polymer blends or copolymers can degrade when exposed to bioactive environments such as soil and compost; (5)with truly biodegradable materials obtained from petroleum and natural resources, opportunity for using biodegradable polymers as agricultural mulch films has become more viable; and (6) the source of polymer and additives may limit use of some biodegradable mulches in organic production. More knowledge is needed on the effect of biodegradable mulches on crop growth, microclimate modifications, soil biota, soil fertility, and yields. © The Author(s) 2012.
Anita B.,Tamil Nadu Agricultural University
Journal of Biopesticides | Year: 2012
The biocidal activity of various isothiocyanates (ITCs) released by Brassica tissues is well-known for its potential to suppress a range of soil-borne pests and diseases. A study was carried out to evaluate the effect of incorporating fresh crucifer residue on root knot nematode, Meloidogyne hapla inoculum density, root knot disease development and celery yield. The ethanol extracts of cabbage, cauliflower, radish and Chinese cabbage leaves after harvest was applied to moist soil with high nematode population and covered with low density polyethylene sheets (50 micron thickness). After 15 days the sheet was removed and celery seedlings were planted. Observation on shoot length, root length, green leaf and stalk yield and nematode population were recorded. Biofumigation with sulphur containing cruciferous vegetable waste at the rate of 1kg/5 kg soil was found to reduce significantly the root knot nematode, M.hapla infecting celery and enhance plant growth and yield. Among the various sources evaluated radish leaf residue was the most effective resulting in 60.6 % reduction in nematode population in soil and 41.9% increase in celery green leaf and stalk yield compared to untreated control. © JBiopest.
Balasubramani P.,SRM University |
Viswanathan R.,Tamil Nadu Agricultural University |
Vairamani M.,SRM University
Biosystems Engineering | Year: 2013
Microencapsulation of garlic oleoresin by spray-drying technology using maltodextrin as a wall material was studied for the treatments designed in Design Expert 7.0.0 software package using response surface methodology. The study was carried out with variable core material concentrations (10, 20 and 30%), drying inlet air temperatures (180, 200 and 220 °C) and different wall material concentrations (40, 50 and 60%). The microcapsules were evaluated for allicin content and moisture content. The optimum conditions were found to be 60% maltodextrin as wall material and 10% garlic oleoresin as core material at 202 °C drying inlet air temperature (R2 = 0.988 for allicin and R2 = 0.990 moisture content). © 2012 IAgrE.