295 research outputs found
Determining the lethal concentration (LC50 96h) of butachlor herbicide for Acipenser persicus and Acipenser stellatus fingerlings
The toxic effects of the herbicide Butachlor were studied using a concentration of 0.4-1.3ppm and 0/1-1ppm on fingerlings of the Persian sturgeon, Acipenser persicus, and Stellatus sturgeon, Acipenser stellatus, respectively in 1999. We carried out six treatments with three replicates and used one control based on the static O.E.C. D. method. Over the experiments, pH ranged between 6.7 -8.2, total hardness was measured to be 230 mg/l, water temperature was 20 plus or minus 1 degrees centigrade and dissolved oxygen was above 6 mg/l. We found that the LC50 96h of the Butachlor on fingerlings of the Persian sturgeon, Acipenser persicus, and Stellatus sturgeon, Acipenser stellatus, weighing 1-3 grams was 0.44 and 0.07 mg/l respectively. Also assessed the LC10, LC50, LC90 of the herbicide on the fingerlings of the sturgeons using the Probit Analysis procedure. We determined the maximum allowable concentration of the Butachlor herbicide for the fingerlings of the Persian sturgeons, Acipenser persicus, and Stellatus sturgeons, Acipenser stellatus, to be 0.044 and 0.007 mg/l. Based on the standards, the herbicide is considered highly toxic for the studied fingerlings
Morphometric analysis of the common carp, (Cyprinus carpio Linnaeus, 1758) in Anzali Lagoon, south west Caspian Sea
We used electroshocker, cast net and gillnet twice a week in four areas of Anzali Lagoon from April to September 2001 to sample common carp (Cyprinus carpio). Specimens were subjected to biometric measurments in the lab. In all, eighteen morphometric and seven meristic measurements were done on the samples. We determined the equation for the fish total fork length and body weight for males and females. Also, Van Bertalanffy growth model was applied to the male and female fish
Toxicity and LC50 determination of phenol and 1-Naphtol in Caspian Kutum and bream fingerlings
In this investigation acute toxicity of phenol and 1-naphthol were determined based on OECD guideline in the laboratory. Experimental fishes were Caspian kutum (Rutilus frisii kutum) and bream (Abramis brama orientalis). Static bioassays were used for acute toxicity tests during the period of 96 hours and all of important physicochemical parameters of water including pH, dissolved oxygen, hardness, temperature and conductivity were monitored continuously and maintained at a constant value. Five treatments were used and three replicates run for each treatment. The 96h LCSO values of phenol and 1-naphthol for Caspian kutum and bream were 21.5928 and 2.1544 mg/lit and 25.1880 and 2.8490 mg/lit, respectively. The Maximum Allowable Concentration (MAC) of phenol in Caspian kutum and bream were 2.1593 and 2.5188 mg/lit, respectively. The MAC value of 1-naphthol in Caspian kutum and bream were 0.2154 and 0.2849 mg/lit, respectively. It is evident from the results of the present study that Caspian kutum is more sensitive comparing to bream and the toxicity of I-naphthol is higher than phenol
The determination of LC50 of diazinon and it's sub-lettal effect on haematological indices of beluga (Huso huso)
The acute toxicity and effects of diazinon on some hematological indices of Beluga (Huso huso) juveniles weighting 4.1±0.12 grams was assessed following the 0.E.C.D. direction in a static temperature in the range 20.27±2.05°C. The 96h LC50 value of diazinon for beluga juveniles was 5.821. Also, the maximum allowable concentration of diazinon in natural waters for beluga was determined to be 0.5821mg/L. Based on the toxicity table of insecticides, diazinon was listed as toxic for beluga .The clinical symptoms that were observed in this study consisted of lordosis and neural paralytic syndrome in fish exposed to the pesticide. Some abnormal reactions such as losing the balance when swimming and swimming in a half circle; expressive pigmentation mainly on the dorsal part were seen in the juveniles. Examination of hematological indices was performed on control and experimental specimens of beluga weighting 16.08 grams on average that were treated with 96h exposure to diazinon in a concentration lower than LC50 96h. The experimental group of beluga showed significantly lower value (P<0.05) of ,erythrocyte (RBC) and leukocyte count, hemoglobin content (Hb), and haematocrite (PCV), MCV, MCH and relative lymphocyte and eosinophil counts compared to the control group In comparison, the relative heterophil count in the juveniles of the experimental group was significantly higher than the control group. By observing a decrease in the amount of leukocyte profile specially lymphocytes which are important in non-specific immunity of the fish, it can be said that diazinon may cause a decrease in the non-specific immunity of beluga
Effect of irrigation frequency and application levels of sulphur fertilizer on water use efficiency and yield of Indian mustard (Brassica juncea)
A field experiment was conducted at Indian Agricultural Research Institute, New Delhi during the crop season of 2007 to 2008 and 2008 to 2009 to study the effect of irrigation and sulphur on yield and water use efficiency of Indian mustard (Brassica juncea var. PusaJagannath). The experiment was carried out in split plot design with three replications. The treatments consisted of three levels of irrigation in the main plots [no irrigation, one irrigation at 45 days after sowing (DAS), and two irrigations at 45 DAS and 90 DAS] and four levels of sulphur in sub-plots (0, 15, 30, and 45 kg S/ha). The results showed that in both years of experimentation, application of two irrigations significantly increased the India mustard yield as indicated by dry matter accumulation, seed production, biological/biomass yield, and harvest index, in comparison to no irrigation. Also, the application of two irrigations, been on par with one irrigation, significantly enhanced seed and biological yield to 20.6 and 78.0 q/ha respectively in the first year, and 22.9 and 86.7 q/ha respectively in the second year, and the highest harvest index was obtained from the application of two irrigations in both years of the study. Water use efficiency as indicated by seasonal consumptive water use increased progressively with the increasing number of irrigations. Also, the amount of soil moisture extraction by the crop from upper layers increased and those from lower depth decreased with increase in the level of irrigation (from no irrigation to two irrigations) in both years of the study. Application of two irrigations to mustard gave higher net (yield) return and benefit-cost (B: C ratio) over one irrigation, which in turn, gave higher net benefit-cost return and B: C ratio than no irrigation. The increasing levels of sulphur application increased Indian mustard dry matter accumulation, seed and biological yield and harvest index. Seasonal consumptive water use by the crop and water use efficiency increased progressively with the increase level of sulphur application up to 45 kg S/ha . Quantity of soil moisture extraction from deeper layer increased with increase in the levels of sulphur application.Key words: Indian mustard, Irrigation, Sulphur, Water use efficiency, Economic evaluation
Pengaruh Kesehatan, Pelatihan Dan Penggunaan Alat Pelindung Diri Terhadap Kecelakaan Kerja Pada Pekerja Konstruksi Di Kota Tomohon
Faktor sumber daya manusia memegang peranan penting dan menentukan sukses atau tidaknya suatu pekerjaan konstruksi. Masalah keselamatan kerja pada pekerja konstruksi masih kurang diperhatikan, masih banyak pekerjaan konstruksi yang mengabaikan faktor keselamatan kerja seperti tidak menggunakan alat pelindung diri. Tujuan dilaksanakannya penelitian ini adalah untuk menganalisa pengaruh kesehatan, pelatihan dan penggunaan alat pelindung diri terhadap kecelakaan kerja pada pekerja konstruksi di kota Tomohon.Metode survey digunakan untuk mendapatkan data utama, dengan cara menyebarkan kuesioner untuk diisi oleh para pekerja konstruksi di kota Tomohon. Populasi penelitian ini sebanyak 3314 pekerja konstruksi, dengan sampel 370 pekerja. Data dianalisa dengan menggunakan uji korelasi dan analisis regresi linier berganda.Hasil penelitian menunjukkan bahwa faktor kesehatan, pelatihan dan penggunaan alat pelindung diri memiliki hubungan negatif dengan kecelakaan kerja, dimana semakin meningkatnya nilai ketiga faktor ini akan menurunkan potensi terjadinya kecelakaan kerja pada pekerja konstruksi di kota Tomohon
Effect of fertilizer in controlling weeds under intercropping of pearl millet and red bean in Sistan region, Iran
This experiment was conducted at the Agriculture Research Center of Zabol University during 2007 cropping season. The experimental design was split plot, using randomized complete block design with three replications. The factors included were, main factors: unfertilized (F1), 100% fertilizer (F2), 100% manure (F3), 50% fertilizer + 50% manure (F4) and five sub factors: sole crop of millet (I1), 75% millet + 25% bean (I2), 50% millet + 50% bean (I3), 25% millet + 75% bean (I4) and sole crop of bean (I5). The plants were planted as replacement method. The results showed that the lowest dry matter for crops and total dry matter of weeds was achieved from 50% fertilizer + 50% manure treatment. Also, the highest total dry matter of millet and bean was obtained from this treatment. The highest dry matter of millet and bean was obtained from the sole crop of millet and bean. Further, the highest total dry matter of millet and bean was achieved from the intercropping treatments. The land equivalent ratio (LER) for most of the intercropping treatments was greater than one which indicated that intercropping had advantage over sole crop. Comparing the performance of sole crop and intercrop treatments, the results indicated that intercropping combinations were more advantageous in terms of weed control.Key words: Intercropping, pearl millet, red bean, weeds, land equivalent ratio, yield
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