Caspian Journal of Environmental Sciences
Volume:3 Issue: 1, Winter 2005

The search for alternative ways of controlling sericultural pests has led to the investigation of plant sources for naturally occurring compounds which may have Insect growth regulatory, feeding deterrency, repellency and confusantcy characteristics. More than 2000 species of the families Asteraceae, Fabaceae and Euphorbiaceae are known that possess some insecticidal activity. Plants with insecticidal properties found in India are reported. But to use them it is necessary to conduct an analysis of the risks to the environment and to human health. Various parts of rotenone, pyrethrum, sabadilla, ryania and neem are often used to minimize pest population. Recently several other plants viz. Pongamia, Indian privet, Adathoda, Chrysanthemum, Turmeric, Onion, Garlic, Tobacco, Basili, Custard apple, Ginger and some other plants have been screened and their efficacy has been tested. The efficacy of leaf extracts of basil (Ocimum basilicum), bitter leaf (Vernonia amygdalina), lemon grass (Cymbopogen citratus), and Chenopodium ambroissoides was investigated for its insecticidal and ovicidal activity against coleopteran bruchids. Several citrus limonoids and limonin derivatives have been found to be insect antifeedants. Among all the plant originated insecticides, neem (Azadirachta indica, A. juss) is known to contain diverse array of biologically active principles of which azadirachtin (a tetranortriterpenoid) is the best known derivatives which is used in sericulture to control various pests. Botanical insecticides are prepared in the form of the crude plant material, extracts or resins. This paper includes the plants that have been reported to be insecticidal against the pests, which visit seri-ecosystem and damage the silkworm and its host plants.

Irrigation with distillery effluent, besides influencing crop yield, may have considerable impact on physical properties of soil because of its high salt and organic carbon contents. This experimental study was conducted to evaluate the effect of distillery effluent on hydraulic conductivity of a sandy loam alluvial soil and compare the effect of inorganic salts of potassium (K) with that of distillery effluent on hydraulic conductivity of soil. The treatments consisted of 4 sources of K: potassium chloride, potassium sulphate, post methantion distillery effluent (PME) and oxidized PME (PME minus organic carbon) at 4 levels equivalent to 10, 20, 40 and 100% of the K concentration in the PME. There were 4 replications for each treatment. Soils, collected from the upper 15 cm of a farm were crushed, passed through a 2-mm sieve and packed in 6.5 cm diameter and 50 cm long columns. Each of the solutions was applied 4 times at the interval of 20 days to the soil column, which were subsequently flushed with distilled water and saturated hydraulic conductivity of soil was measured using the constant head technique. Application of PME and salts increased the hydraulic conductivity of soil to 3 to 4 fold as compared to that of the untreated soil. With the increasing levels of salt concentration, the rate of increase in hydraulic conductivity initially decreased, but at 100% salt level soil hydraulic conductivity increased sharply. The oxidized PME, which contained only the inorganic salts present in the PME, had highest hydraulic conductivity at 100% salt level followed by PME and inorganic salts. The exchangeable K content of soil (x) and hydraulic conductivity (y) showed a polynomial relationship (y = 15.28 – 1.61x 0.05x2). The study showed that application of PME has significant impacts on soil hydraulic conductivity suggesting that impact assessment of PME application on physical properties of soil be recommended to find an optimum application rate before the practice is adopted.

The present study deals with the oral supplementation with (50, 100 and 150 μg/ml) synergetic effect of potassium and magnesium chloride on the fat body glycogen, protein, total lipids and haemolymph trehalose, protein of fifth instar larvae of Bombyx mori L (Lepidoptera: Bombycidae). The observed parameters significantly increased in all the treated groups when compared with those of the corresponding parameters of the carrier control. These results may suggest that the minerals may stimulate the enzyme activity which influences the metabolic process thereby increasing the biochemical contents of the fat body and haemolymph of the silkworm, B. mori L.

The effect of fungicides on silkworm larvae was analyzed with regard to the fact that these beneficial insects are usually affected by fungicides, Daily feeding on 1 and 2g/liter of carbendazim, a systemic fungicide, did not have significant effects on larval and pupal mortality. However the weight of the treated larvae showed considerable weight decrease up to 37% weight.. All the economic traits of male and female adults treated with fungicide decreased but this decrease is not significant in cocoon shell weight and hatching percentage. The comparison of means using Tukey test at 5% confidence level did not show any effect related to the concentration

A field study was conducted at five villages of Botswana namely, Tsabong, Tshane, Mathathane, Motlhabaneng and Tsetsejwe during the periods of June to August 1999 and June to August 2000. The objective of the study was to assess and compare the soil physicochemical properties of soils at the five villages and to study the effect of cultivation on some soil physical properties. Parameters measured in the field included soil pH, organic carbon (OC), phosphorus (P), cation exchange capacity (CEC), exchangeable cations (Ca, Mg, K and Na), bulk density (BD), soil penetration resistance and infiltration rate. Soil pH, OC, CEC, Mg, Ca and BD were found to be significantly different in the five villages. The non-cultivated soil was found to have significantly lower bulk density, higher infiltration rate and higher penetration resistance compared to the cultivated soil. Soil from the Kgalagadi area was found to be significantly lower in nutrients in comparison with the soil from the Bobirwa area. The cultivated soil was found to have higher, bulk density, lower infiltration rate and lower penetration resistance.

Phytoextraction is a remediation technology that uses plants to remove heavy metals from soil. The success of a phytoextraction process depends on adequate plant yield (aerial parts) and high metal concentrations in plant shoots. A pot experiment was conducted to investigate the combination effects of plants [sunflower (Helianthus annuus) and canola (Brassica napus)] with soil treatments (manure, sulfuric acid and DTPA). Treatments, included two plants and seven soil treatments, which were applied baeed on a completely randomized factorial design. Three replicates were used for each treatment.. The largest shoot dry weight biomass production occurred in manure treatments for both plants. The maximum shoot concentrations of Pb and Zn were 234.6 and 1364.4 mg kg-1 respectively in three mmoles DTPA kg-1 treatment of sunflower. Furthermore the results showed that sunflower had a higher extracting potential for removal of Pb and Zn from polluted soil.

Three experiments of 60 days duration were conducted in post larval stage of Indian white shrimp, Fenneropenaeus indicus, to explore the appropriate protein: lipid ratios in their diets. A common ingredient mixture consisting of; fish meal, shrimp meal, ground nut oil cake, cholesterol, lecithin, vitamins and minerals blended with chicken egg albumin, tapioca flour and cellulose (filler) was used to formulate nine feeds with protein levels of 35%, 40% and 45% and lipid levels of 6%, 9% and 12%. Nutritional responses in terms of WG, RGR, FCR, FCE, PER and PLV indicated that there was no 2-way significant (p>0.05) interaction between protein and lipids levels in any of parameters mentioned; however, the effect of lipids, when tested individually, showed significant variation (P> 0.05). Comparison of mean values showedsignificantly higher WG, RGR, lower FCR, higher FCE and decreased PLV in 45% protein and 12% lipids.

Over the years, there has been an obvious pollution problem in Lagos area, Nigeria with high population of over eleven million and the near absence of waste management infrastructures.
Concentrations of some pollution parameters and trace elements (temperature, pH, salinity, SO42-, NO3-, PO43-, F-, DO, BOD, COD and coliform, Cr, Co, Ni, Ag, Cd and Pb) were determined from water bodies of Isolo Canal, Lagos lagoon and the Seaport in Lagos area, during the rainy season (July, August, September and October) of 2002. Temperature was fairly constant with a range of 26 – 31oC while salinity, SO42-, NO3-,
BOD, COD decreased in the three water bodies as the rains increased. DO and coliform counts increased, while F- was almost constant during the same period. Phosphate was below detection limit in all the water bodies. The concentrations of dissolved metals varied between the water bodies. The concentration of Pb was found to be highest in the Sea and Cd was not detected in all the water bodies. The concentrations of
the Cr, Co, Ni and Ag varied differently with salinity in all the water bodies. Pb concentrations did not show any significant variation with salinity in all the water bodies.

Forests of Iran located on the Southern border of the Caspian Sea cover 1.9 million hectares. The Caspian forests are divided into four separate forestry areas. One of these being Guilan influx area with total area of 565000 hectares. About 30 to 40 percent of Guilan province forests are suitable to short rotation forestry for afforestation. Slash pine (Pinus elliottii) is one of the main exotic species planted in the Guilan province. The objectives of this research were to estimate: stand parameters, form factors and a provisional volume table of Slash pine planted forest stands. A total of 142 individual trees were randomly sampled. Individual tree variables such as: dbh, height, volume, and form factors (f13, fm, f0.1 and fh) were measured and analyzed. The site index quality of study area, were broadly compared with stands of site index in the southeast USA. The results were shown that the site index quality at the study area in the north of Iran in agreement and parallel with stands of site index is 21m (63 Ft.) in the southeast USA. Therefore, operation of Slash pine is satisfied as short rotation forestry in the Guilan province of Iran.

The yield loss simulation (YLS) and the MACROS LIQ.CSM models were used to simulate the effect of stem borer damage at a detillering rate of 5, 15, 30, 60% at vegetative, panicle initiation and grain filing stages, on yield of rice cultivar’s Ratna. This stem borer damage during vegetative and panicle initiation stages was not simulated appropriately by both the models. Relatively MACROS simulated pest effects better than YLS at this stage. The predicted reduction in yield due to detillering at grain filling stage varied from 10.93-62.5 and 2.59-57.2% with the YLS and MACROS models, respectively in comparison to observed reduction of 4.8-56.1%. The simulated and observed pest effects on crop yield during grain filling stage were found to be comparable.