Year:2001 | Volume:13 | Issue:4 (49)|Papers Count:39

The main objective of this 'experiment was evaluation alfalfa varieties for susceptibility and resistance fo Fusarium spp. In greenhouse condition Greenhouse experiment was established for twenty alfalfa varieties. Twenty alfalfa cultivars contain American and European varieties. With refer to the result section; the evaluation of varieties was carried out on the basis of symptoms on the samples of plants and on cross section of their roots. Some varieties showed as level of resistance and other varieties had medium susceptibility, also there were some varieties have showed high susceptibility. The results showed significance difference between varieties.

Elecampane (Inula helenium L. Compositae) is a perennial plant found in damp medows and shaded areas of central Europe. It is most commonly found in the wild state in Iran. In this resaerch, plant are collected from Hamedan city on west of Iran. Essential oil was extracted from flower by two methods (Steam distillation and hydro distillation) and root by hydrodistillation method. The percentage of oil from flower 0.07% and root 0.06% are calculated, and analysed by GC and GC/MS. The main components for flower by steam distillation Oplopenone (19.1%), a-Cadinol (5.1 %), T-Cadinol (4.9%) d-Cadinene (4.50%) and Curdione (4.2%) and by hydro distillation Globulol (7.2%), Cadalene (7%), d-Cadinene (6.7%), Torreyol (6.1%) and Oplepenone (5.1 %). The main Components for root by hyrdrodistillation are Alantolactone (24.9%), Spathulenol (10.8%), (E-E)-Farnesol (8.1%) and Ledol (7.4%).

The rRNA genes are essential for the survival of all organisms and also the sequences of these genes are highly conserved. For this reason, the determination of 168 rRNA gene sequences is used as a standard method for the identification of species, genera and families of bacteria. Recently, the small parts of the rRNA gene sequences are used for bacterial assessing at the level of genus and above. The data obtained from the sequences of the small parts of 168 rRNA suggest that rhizobium genus can be split into four genera. In this investigation, two rhizobial isolates were isolated from the hairy vetch plant nodules (Viciae hirsuta) and they had different plasmid profile types. By using two specific primers, the first part of the 168 rRNA gene (about 230 base pairs) were amplified by using PCR technique. The 168 rRNA gene sequences of two isolates were compared with those in the gene bank database. The results showed that the sequences of two isolate had 100% homology with those in Rhizobuim leguminosarum' bv. Viciae. Therefore, The sequences determination of 168 rRNA gene is a useful and reliable method for rhizobia identification.

The allelopathic effects of bryony on the growth of wheat and radish seedlings were investigated. The existing inhibitor in wet extracts of leaf, root, stem and fruit prevented the growth of wheat and radish seedlings. The effect of aqueous extract was stronger than organic ones. So, the inhibiting compound is soluble in water. The effect of ash extract was the same as control. This finding indicates that the inhibiting compound is destroyed by heat. The inhibiting compound prevented' the growth of wheat in soil too. In this study, the effect of fruit extract was stronger than all organs while the effect of stem was the weakest. The inhibitory effect of active ingredient on root and shoot growth was differential and it reduced the root growth more than shoot growth. On the other hand, the effect of inhibiting compound on different species was not the same and it reduced radish growth more than wheat growth. This finding reveals the selective character of inhibiting compound. The final result is that, bryony is an allelopathic plant.

Pistachio has special position in the economy of Iran. In this regard, a substantial pistachio production of Iran has exported to the overseas for earning foreign currencies. However, a substantial amount of product is lost every year by spring cold damage. This research has conducted with the aim of induction of flowering delay in pistachio (Pistacia veraL.) for prevention of spring cold damage. For this purpose mature pistachio trees cultivars Kaleh-Ghoochi and Ovhady trees were sprayed using soyebean oil and paclobutrazol (PBZ) in two separate experiments. Experiment one estabvlished to explore the effect of soybean oil on flowering delay of cv. Kaleh-Ghoochi.Soybean oil treatments (0, 2.5, and 10% v/v) were sprayed at 25,35 and 60 days before anthesis during dormant period. In the second experiment PBZ treatments (0, 0.5 and 1.5 g.al tree-1) were applied to the soil May, September and April. The results from the first experiment (soybean oil) indicated that there was not any indication of flowering delay in the subsequent year of treatments application on Kaleh-Ghoochi cultivar.However, results on the second experiment (PBZ treatments) showed delay of flowering on Ovhady cultivar in the year after treatments application. In addition, PBZ treatment applied on May showed better result than September and May application. It was not any significant differences between low (0.5 g.al tree-1) and high (0.5 g.ai tree-1) rate of PBZ. Considering the importance of flowering delay in oder to overcome spring cold damage, it seems that PBZ is able to regulate flowring time of pistachio trees. Since, interactions exist between genotypes and plant hormones, therefore this type of experiments would be suggested tobe carried out on different pistachio cultivars.

A rainfall intensity (Depth), duration, frequency (IDF or DDF) relationship is needed for planning of water resources projects. The frequencies of high-intensity rainfalls is required for several engineering purpose, one of the most important is the estimation of extreme floods for inadequately gauged basins. In general, rainfall is associated with the floods of sub catchment or small catchment of shorter duration, similarly where the stream size decrease, their chances of being adequately gauged also decrease, and so it may be argued that short – duration rainfalls of less than 2 or 3 hr are of special importance in flood estimation. In this study the analysis of DDF for Iran has been carried out using synoptic meteorological stations and depth - duration ratio of shorter durations (15 minutes to 12 hr) to maximum 24hr (Rt/24) in all existing station. By using these values, isolation maps were plotted and than the median values of Rt/24 were selected for any climatic regions. The DDF relationship of rainfall for any climatic regions of Iran obtained by regression method based on duration and Rt/24.

After growing of mushroom mycelium into compost and changing the vegetative to reproductive phase, it is necessary to cover the surface of bed with a layer of casing soil. Cultivation of mushroom in Iran facing many difficulties. One of them which cause problems for grower is casing soil. Black peat is not available and source of local peat which is belonging to north is limited. Spent mushroom compost (SMC) can be one of the Alternative materials. For present investigation three years old (SMC) was leached at ratio of 1:4 and 1:8 (SMC/water, v/v). Five replication fo each were made. Physical, chemical, microbial, grow1h of mycelium and mushroom production of leached and non-leached were compared using student T-test. No significant difference was observed, except the amount of potassium and electrical conductivity. There were no significant difference also between both leached (SMC) and local peat with regard to mushroom yield. The result indicates that leached (SMC) can be an alternative material for casing soil.

P. atlantica is an economically valuable forest tree that grows extensively in mountainous regions of eastern, western and southwestern provinces of Iran. Although, P. atlantica develops extensive root system there is little information regarding its roots symbiosis. Mycorrihizal symbiosis which facilitates water and nutrients uptake was investigated in P. atlantica roots in Yazd province, Iran during 1996. Fungal spore abundance and mycorrhizal infection rate were determined in relation to soil factors and altitude from sea level. P. atlantica roots are symbiotic with species of vesicular. arbuscular fungi such as, Glomus fasiculatum, G. occultum, G. clairoideum, Acaulospora laevis, A. bireticulata, A. scorbiculata and unknown Acaulospora species. Low P snd K and adequate N in a near neutral or alkaline sandy soil enriched with organic carbon favors mycorrhiazal development; But mycorrhizal fungal spore abundance and number of fungal species decrease with an increase in altitude from sea level.

For determining of effect of skidding distance on forest road density, skidding time (time study) have been measured for skidder in 2 parcelles between the felling area and depot, and then primay data have been recorded into computer program spss (80 time (cycle) and by regression equation were analyzed and the results are presented of an 8 - day skidding operation: Total 342 m3 had extracted from area during skidding time 16h, 11m and 29 seconds, or 21.12 m3 per hour. Average skidding time is at each time 12 minutes and 9 seconds and average extracted volume calculated 4.28 m3. By increase of skidding distance, skidding time, skidding cost and road spacing are increased (linear and direct relation), but road density and road construction expenses are decreased (curval and inverted relation). Optimum road density is 28 m/ha including 14m main road and 14m secondary road and optimum skidding distance obtained 250 meter (at gradients of lowest 20%).

Erosion is a dangerous phenomenon that threatens the land of th world and is considerd as a serious problem. On the other hand the hazardous effects of soil concentration erosion continuously increase. This, along with scalation of the population made people exploit agricultural lands for challenging with starvation. As a results of this action, soil erosion will further causing additional starvation. Sheet and rill erosion are two types of erosion in Qomrood watershed that have been often observed in pastures. In this study, after superposing the maps of soil, geology, slope, landuse and climate, more than 150 homogenous units were identified and the following factors for them was determined: i. e. the senility of rocks for erosion, average slope, percentage of bare soil and vegetation cover and CN variables. The severity of each and the total erosion were measured by using S.L. M method. The relationships between severity of sheet and rill erosion forms to the given factors were evaluated using correlation matrix and stepwise regression multiple method. The results show that the soil and rock sensivity for erosion are the main factors affecting sheet and rill erosion in cold semiarid and cold temperate climates. Meanwhile, the accuracy of the resulting models were verified with independent data from the study area. The result of this study can be used to predict the severity of erosion in different forms even for the areas with similar climates, but facing lack of data.

Nowadays, presence of the heavy metals in agricultural soils is becoming a serious environmental issue. The heavy metals in soils affect the microbial population such as bacteria and make them more resistant to these pollutants. In this research 11 soil samples from 11 point Lenjan agricultural areas around the Zayandehrood river in Isfahan were studied and 23 species of bacteria resistant to lead and cadmium from standard plate count method (SPC) were isolated. The isolated bacterial species belong to bacillus, sporolactobacillus, lactobacillus and arcanobacterium genuses. As a second step, by agar dilution method the minimum inhibitory concentration (MIC) and absorption ability of these bacteria were studied with atomic absorbtion spectrometer (Philip model PU 9100) and their resistance to other metals was also evaluated. The results of this study indicated that, environmental factors such as the presence of metals in soil and soil texture can affect the percentage of the resistant bacteria and their tolerance toward the metals. In this study the effect of lead and cadmium on soils bacteria of Lenjan area was evaluated. Lenjan area is located about 20 kilometers at south west of Isfahan province. For the agricultural activates. This area is very intense, and the place is well known for its rice. In northeast of the Lenjan valley, the Irankouh mountain is located which is the place of Iran kouh zinc, lead and cadmium. mine, and since the soils in this area, are natural rich in these metals, the bacteria have been affected by the pollutants. From mine and probably by the irrigation water from Zayandehrood river.

Improvement and recognizing of alfalfa varieties for resistance and susceptibility against Fusarim spp. Was the basis of our studying during the experiment. The brief of activitiesare presented as follow: collection of infected plants, determination, purification, culturing, and preparation of inoculums source (Fusarium spp.) for artificial infection. Seed trial was established in laboratory for two sorts of varieties. One of them was twenty alfalfa cultivars containing foreign varieties and the other one was five alfalfa cultivars containing two Iranian cultivars (perennial and annual species) and three foreign varieties. The main objective fo this study was evaluation of the germinated seeds for susceptibility against Fusarium spp. The results showed some varieties had a level of resistance and other varieties had medium susceptibility and also there were some varieties that have shown high susceptibility.

The major secondary metabolites crocin, picrocrocin and saffranal are important for high quality of saffron: The major pigment of natural stigmata (44% from total pigment). Were observed in in vitro stigma-like structure (48% from total pigment). picrocrocin which was identified from absorption point, detected only in natural sigmata. After crocin, monogenibioside monoglucoside esters of crocetin are important. These pigment were presented in stigma-like structures and stigmata in nearly equal percent (33% from total pigment in stigma-like structures and 32% from total pigment in natural stigmata). Diglucoside esters of crocetin (14% from total pigment in natural stigmata and 12% from total pigment in stigma-like structures) and one of the crocetin ester types (6.1% in natural stigmata and 5.8% in stigma-like structures), were also detected. The direct stigma-like structures (were produced in low ratio NAA to BAP were more similar to natural stigmata than the indirect types (were produced in high ratio of NAA to BAP) in shape, colour & size.

Explant of Atriplex halimus was cultured at two different medium (MS and LS) including kinetin (0.1 mg/L) and proline (50 mg/L) at 25C and photoperiod about 16 hours. The effect of different concentration of NaCl (1% and 2%) and proline on the growth of the species was studied. The result of study showed that NaCl at concentration 1% increased significantly the rate of shoot production growth of Atriplex halimus, but at 2% concentration showed negative effect. Proline at 100 mg/L concentration decreased the rate of shoot and root production when used together 1% NaCl, but had vice versa effect with 2% NaCl.

The effect of four levels of salinity (0, 50, 100 and. 150mM Nacl) on growth, photosyn the- sis and water relations in three grasses "Lolium multitlorum, Lolium perenne and Festuca arundinacea" was studied.  We report a differential response of Lolium and Festuca species to Nacl salinity where Festuca was found to be more resistant than Lolium species. Nacl induced more reduction in dry weight and photosynthetic rate Lolium species than F. arundinacea. The F. arundiacea and L. multiflorum was able to adjust osmotic partially. But L. perenne was failed in such a mechanism. This disability might be reduced growth of L. perenne drastically. The differences between Festucaand L. multiflorum might be related to Na+ exclusion that need further experiment.

Although saffron has a good economical value among crops, but there is not enough research work on its ecological factors, especially the effect of temperature on its flowering. The effect of temperature has been studied on flowering date and yield of six accession of Iranian saffron during 1990-97.The experiment carried out Ina split - split plot incomplete randomized block design, Alls affron accessions started flowering from 12.2 to 14.2°c, the saffron's yield increased by the age of farm till4th to 5th year and then the yield decreased. Tourbat-Heidarieh was the highest yielding (P³%1) saffron among the 6 studied accessions.

Salin and alkalin lands occupy a vast part of the world land areas. The majority of such lands are located around the Kavir and in such a condition, the production of a great variety of the plant species occurs only with a great limitation and also the agricultural utilization dosen't have any economical expfanation. According to the literature, salin lands in Iran covers 20 million hectars of the country. As mentioned above, with increasing human population, it's essential to have some programs in order to optimize utilization of present potencial of such soil and water resources. Present investigation was carried out on the Kavir of Meyghan which is located 15 km far in north eastern part of the city of Arak which its environmental characterisitics is of great importance. Phytosociological investigations were carried out on the basis of determination of the vegetation types and their relationship to environmental gradiants. Radius sampling with three different axes and different angles (120) were taken, topographical map, arial photograph as well as field I vegetation survey were used to determine , vegetation bondary, then among vegetation type, the samples of soils, water and different vegetation parameter were taken. The results obtained are as followings: 1- The soils of the area were recognized as sodic but soils closer to the center of Kavirare more saline than those farther from the center. The amount of salt is 10.28 ds/m2 in the northern part of the Kavir and 123 ds/m2 around the center. It should be noted that the area of 12000 ha on the center of Kavirhas become as a salt marsh. 2- The underground water possesses different flactuations on different seasons of the year mainly because of the different flood water streams on wet season as well as over withdrawal of water from agricultural wells and evapotranspiration on dry season, consequently the level of underground water are increasing toward the center of the Kaviron dry season, whereas it is inversely on wet season. 3- On the basis of this study, 10 different vegetation types were recognized on the area, the species of Halocnemum strobileum because of its resistance to such a condition has become as a vegetation type alone. The vegetative covers 15% of the area with EC 123 ds/m2. The species Puccinelia bulbosea in northern part of the Kavir vegetative covers %80.8 of the area with EC 10.28 ds/m2. 4- It is concluded that with control of water withdrawal and delaying flood water stream causes, the level of underground water less flactuate and as a result salinization of soils in above surface profile being decreased, consequently more palatable species such as Puccinelia bulbosa established.

Pollen analysis of honey (Melissopalynology) is an essential tool to access the botanical and geographical origin of honeys and their quality, and to understand the foraging ecology of bees. In this survay, pollen extractions of 10 honey samples from Khorassan province were studied. 43 pollen types from 28 plant families were identified and the proportion of pollen types in each honey sample was determined. Pollen grains from composite and leguminosae have been readily collected by honeybees, thus most of honey have a good quality. pollen spectra of honeys varies from 11 to 22 pollen types. Many pollen grains which have an important foraging role for bees, were observed in fewer amount in all honey samples. Quantitative analysis showed most of the samples has a deficit in absolute pollen concentration.

D. salina is a unicellular alga with two flagella. This organism belongs to volvocales. In these studies two strains of D. salina were chosen. One of the strains isolated from the Namakdan mountain in Gheshm Island and designated as strain A, the second strain obtained from center of Marine Biotechnology, Baltimore, Maryland U.S.A and designated as strain B. Jhonson culture medium was used for all the treatment with slight modification at pH 7.5. All the parameters kept constant for glycerol production except Nacl concentration. The glycerol production with both the strains at Nacl concentration of 0.5, 1, 1.5, 2, 2.5, 3 and 3.5 molar checked at 7th (log phase), 16 th (end of log phase) and 25th day (stationary phase) of growth rate. Glycerol was usually assayed as a diol after oxidation with period ate. In each algal treatment the total, extracellular and intracellular glycerol and intracellular glycerol in cell obtained. The maximum production obtained at the end of log phase or beginning stationary phase. A Unbar line obtained between extracellular Nacl concentration and intracellular glycerol in each cell. The maximum glycerol was produced by strain B was 453.9 mg/ml whereas 431.7mg/ml glycerol produced in strain A. (There is accord between Nacl concentration for the optimum growth and the maximum glycerol production in strain B). The optimum Nacl concentration in strain B was 1.5 molar. This accord was not observed in type A, where there was a difference of 1 molar between Nacl concentration for the optimum growth and the maximum glycerol production. Depicted results showed that strain B is a better candidate for glycerol production. Intracellular glycerol extracted.

Regarding to the importance of sturgeons specially persian sturgeon (Acipenser persicus), this study was carried out on the microscopic structures of intestines often adult sturgeons. Routine histological processes were used and stained by hematoxylin and eosin method. Internal sur face of intestines was netted but only distal intestine was distinguished by spiral valves. Epithelium of intestines and the valves were ciliated pseudo stratified columar associated with goblet cells increasing to the end of intestines. Some large saccular glands in the sub mucosa of intestines except rectum were present. At the end of rectum the epithelium gradually changes from columnar to completely stratified scuamous prior to the vent.

A survey has been done on parasites of 234 Acipenser stellatus in three different major location, where the sturgeons are caught, including fisheries regions of 1,2 and a hatchery near the Sefid rud river (Sad-esangar) in south - west of Caspian  sea (Gilan province - Iran). Nine different species of parasites were recovered from internal organs of the fish. Skrjabinopsolus semiarmatus and Leptorhynchoides plagicephalus were the most important parasites of the fish (with the prevalence of 43.15% and 20.18% respectively) but Cucullanus sphaerocephalus, Eubothriumacipenserinum and Bothrimonus tallax were also important, though their prevalence were not too high (17.26%, 9.14% and 4.4% respectively). The prevalence and intensity of Eustrongylides excisus (larvae), Anisakis sp. (larvae), Amphilina toliacea and Corynosoma strumosum were too low. The prevalence and intensity of parasites in fisheries region of 2 and Sad-e sangar were more than region 1. A direct relation was found between some parasites (specially S. semiarmatus) and size (except for L. plagicephalus which has indirect relation). The prevalence and intensity of parasites in females were more than males and also it was found that there is a correlation between some parasites (specially S. semiarmatus) and season. In this survey, again it was found that the internal parasites of A. stellatus in this area (south - west) are the same as northern part of Caspian Sea but the diversity of parasites was fewer than north. Furthermore, the diversity of parasites has been decreased in a period of time (compared with approximately 25 years ago, when the first survey has been done in Iran), though the prevalence and intensity of some parasites appears to be increased during this period.

This project has been conducted in Gorgan bay in 1994. this fish was the little population of gobiidae in Gorgan bay. the frequency much was in january with % 60.5 and the frequency little was in march with %7. The distribution of fish was only in 3th station. The total length and total weight average of all population was 35+5.1 (mm) and 0.34+0.12 (g) respectively. The correlation positive between the total length and weight has been observed more in females than the males. The fish have positive alometric growth rate. The sex ration of male to female was 1:1.1. In addition the average fecundity rate was 395.5 (290-550) eggs depending on the fish.

More than 70 specimens of spiders, which were collected from north of Iran, were reared in laboratory up to 154 days. In this study, some aspects of the life cycle and the predatory behaviors of spiders have been recorded. Reared spiders belong to 8 families and 12 species. Larinoides folium (Araneidae) had the best adaptation to the laboratory conditions and the highest feeding. Theridion hemerobius (Theridiidae) had a complete life cycle from hatching to adulthood.

In order to study the effects of m01asses with IS different amounts of urea in the feeding of fattening male calves, twenty four holstein growing male calves were selected for 112 days of experiment period. Five different diets contain 0, 0.5, 1, 1.5 and 2 percent of urea with 15% molasses and one diet without molasses and urea as a control were studied Concentrations of energy, crude protein and other nutrients in all diets were the same. At the beginning and at the end of experiment calves were o weighed after 16 to 17 hours starvation. During the experiment calves were kept individually and fed ad libitum by total mix ration (TMR). A completely randomized design (6´4) was carried out and data were analized using one way analysis of variance the effect of initial weight was corrected by covariance analysis. Average daily gain daily feed intake and feed conversion ratio were not affected by the experimental diet. Utilization of urea in the diets decreased (P<0.01) feed cost per kilogram of body weight gain. It can be concluded that, the using of 2% urea with 15% molasses could have the positive effects on economic return of fattening male calves if the other nutrients are provided in a balance state.

During the spring of 1995 to spring of 1998, the fauna of snakes and scorpions of Yazd province were studied. The results of the study showed that 2 species of scorpion belonging to Buthidae family are present at the area of study. Out of 400 captured scorpions, 73% belonged to Androctonus crassicauda and 23% to Mesobuthus eupeus. Out of 125 collected snakes, the species were identified and among them Psammophis schokari was more abundant with the frequency of 24% and Vipera lebetna with lowest frequency of 0.8%. Non poisonous snakes have more frequency (46.4%) than accidental poisonous (38.4%) and poisonous snakes (15.2%).

Hitherto, three species of freshwater shrimps, namely Caridina fossarum (Helier, 1862, Caridina babaulti (Bouvier, 1918) and Atyaephyra desmarestii (Millet, 1831) have been recorded from Iran. Because no information was available on distribution of the species, therefore a long term study was conducted to determine their distribution in Iran from 1992 up to now. Instead of providing a specific identification key, a comparative morphological study was carried out. In order to confirm the identification of the species some preserved specimens were sent to prof L.B. Holthuis, crustacea expert at National Museum of Natural History of the Netherlands. The study show that the species do are distributed in the south margin of Zagrous mountains. It seems that altitute is a limiting factor for distribution of the species. Based on Or. Jalihal, et al which introduce caridina species as a potential materials for laboratory research on decapoda, it seems that the species potentially might give us a good chance to study ecology, biology, psychology, genetic, etc. of decapoda.

The present experiment is conducted to compare the composition of colostrum in Golpaigani and Holstein cows, as well as the effects of lactation number on colostral components. Eight colostral samples from 30 Golpaigani and 30 Holstein cows were obtained over 4 days (two times per day) after parturition. Concentration of fat, crude protein, lactose,and total solids of colostrums were not significantly different between Golpaigani and Holstein cows. Lactation number did not affect on colostral composition. Immunoglobulin concentration in first milking of Holstein cows was greater than that of Golpaigani cows. Density of first milking colostrum of Holstein cows was greater than that of Golpaigani cows. Although the accuracy of single radial immunodiffusion was greater than that of zinc sulfate turbidimetry method, we suggest the later method, to determine of whole Immunoglobulin concentration, as it is easier, less costly, and quicker.

A biochemical survey was conducted to provide a reference value for blood serum total protein and its different fractions of caspian miniature horses, and comparing with those of Iranian arab horse. All animals were devided into 4 age related groups. Group 1,0-36 months old, group 2,37-72 months old, group 3, 73-108 months old and group 4, over 109 months old. Comprehensive statistical studies were based on results considering the age, sex and breed. The values of total protein, total globulin and fractions of alfa 2 and beta 2 globulin were higher in caspian horse than in Iranian arab horse, but albumin and albumin/globulin ratio (A/G) were higher in arab horse. Those significant differences were found between the mares of two breeds except for total protein and alfa 2 globulin. In stallions of both breeds, there are differences in the values of alfa 2, beta 2 and the ratio of A/G No sex related differences were observed in amount of total protein and is fractions between males and females of each breed. Age related differences were found as decrease in albumin and increase in gamma globulin with aging of both breeds.

An experiment was conducted to study the milk production, lactation length and lamb growth of 20 Varamini sheep (three years old). Twenty ewes giving birth and rearing either Single and twins lambs (male or female) were chosen from a flocks kept at Animal Research Station, College of Agriculture, Tehran University. Milk production was started day three postpartum and continued weekly for 11 weeks. Daily milk production was estimated over a 6 hour period through a combined lamb suckling – hand milking technique. Means of daily milk productions, lactation length and daily live weight gain of lambs were 345(±12)g, 77(±3) days and 185 (±12) g respectively. The ewes suckling male lambs produced more milk than those suckling female lambs. However, there was no significant effect of the sex of lamb on total milk production. Also ewes suckling twin lambs produced more milk than those suckling single lambs.

Antimicrobial effects of essential oils of Mentha longifolia and Heracleum persicum on E. coli and S.aureus were studied. Disc diffusion method was conduced to evaluate the zone of microbial growth inhibition at various concentrations of the essential oils. The antimicrobial effect was also studied against three different concentrations of microbial suspension to find out MIC (Min inmal Inhibitory Concentration) and MBC (Minimal Bactericidal Concentration). The essential oils from Mentha longifolia and Heracleum persicum were bactericidal and bacteriostatic respectively against both the micro organisms. Gram negative bacteria, E.coli, were readily affected as compared to S.aureus. Chemical composition of the essential oils was analyzed by Gas Chromatography and Mass Spectrometry (GC and GC/MS) Seven common chemical compounds at various concentrations were found in both the oils. Limone of Mentha Longifolia was at the highest level of 13.73 percent, while b-pinene of Heracleum persicum contributed to 7 percent in the common compounds.Antimicrobial effect of Limonene seems to be more probable than b-pinene. With a view to the increasing limitations of the use of chemical antimicrobial agents and development of drug resistance, it seems necessary to switch on to new harmless antimicrobial agents from natural sources.

Supercritical fluid extraction with carbon dioxide is used to extract the essential oils from the medicinal herb, Matricaria chamomilla L. Samples were extracted with supercritical carbon dioxide at 90 bar and 40°c in two separators at 90 bar 5e and 30 bar and - 5°c. The extracts are examined by GC/MS. Chamazulene is an artifact. formed during hydrodistillation from the guajane-type seequiterpenelactone matricin. Major components are bisabolol oxide A and B (50.42% and 16.88%), Cis-dicycloether (0.64%), bisabolone oxide (7.76%).