خيارات البحث
النتائج 1061 - 1070 من 1,442
ZINC AND MANGANESE SORPTION BEHAVIOR BY NATURAL ZEOLITE AND BENTONITE
2011
A.L. Iskander | Khald E.M. | Sheta A.S.
Understanding the sorption process in natural zeolite and bentonite is necessary for effective utilization of these minerals as nutrient adsorbents and on the other side for controlling release of plant nutrients. This research was undertaken to characterize the ability of natural zeolite and bentonite minerals to adsorb and release zinc and manganese. The potentials for sorption of these ions were evaluated by applying the Langmuir and Freundlich equations. The results showed that Langmuir constant [maximum adsorption (b mmol kg-1)] of both Zn and Mn were for bentonite > zeolite While the [binding strength values (k in L.mmol-1)] for zeolite > bentonite Zn in case of zeolite showed the lowest desorbed percentage particularly at high levels of sorbed Zn. Only, 74.7 % is readily extractable by DTPA after three successive extractions leaving, 25.3 % Zn retained by the mineral. In case of bentonite, 82.26 % of sorbed Zn is readily extractable by DTPA after three successive extractions leaving, 17.74 % Zn retained by the mineral. In case of Mn, 84.63% of Mn sorbed by zeolite is readily extractable by DTPA after three successive extractions leaving, 15.37% Mn retained by the mineral. In case of bentonite, 89.79 % of adsorbed Mn is readily extractable by DTPA after three successive extractions leaving, 10.21 % Mn retained by the mineral. This finding may reflect clearly the possibility of using natural zeolite and bentonite as a slow release fertilizer for Zn and Mn and on the other hand preventing soil pollution with heavy metals.
اظهر المزيد [+] اقل [-]ULTRASTRUCTURE OF THE SHEEP NOSE MYASIS OESTRUS OVIS (Linnaeus, 1758) AND CAMEL'S NOSE MYASIS CEPHALOPINA TITILLATOR (Clark, 1797) IN SAUDI ARABIA FARMS
2011
Sara Aljubran | Souad M. Alsaqabi
Farm animals have a high economic importance because of their important products such as meat, milk, hair as well as skin, not only in our country but also all over the world. These animals can be infected by serious pathogens, external and internal parasites causing severe damage, which result in losses of animal production. Accordingly, the study of external parasites with light microscope and scanning electron microscope were recorded, to clarify the exact composition of species. Also, differences in the morphological characteristics between the two Myiasis species: Oestrus ovis (Linnaeus, 1758)and Cephalopina titillator (Clark 1797), were investigated.
اظهر المزيد [+] اقل [-]A STUDY FOR SOME FACTORS AFFECTING ON FARMERS RATIONAL USE OF WATER IRRIGATION IN NEW VALLEY GOVERNORATE
2011
Mahrous Samia A.
The recent study aims to: identify the degree of farmers implementations for the recommendations of the technical rationalization of water use in New valley Governorate. In addition, identifying the independent variables affecting the degree of farmers implementations for the recommendations of the technical rationalization of water use as a dependent variable. In order to accomplish the study objectives, new valley Governorate was selected as a filed study. A systematic random sample of 212 farmers was selected. This sample represents about 5% of the total farmers in three villages in New valley Governorate. A questionnaire was designed and collected using the personal interview (after it was pre- tested) during may 2011. Then, the data were tabulated and analyzed by using simple correlation coefficient, stepwise regression. The study finding showed that about 14% of the total sample have low level of implementations for the recommendations of the technical rationalization of water use. Medium category represents about 50%, and high category of implementations for the recommendations of the technical rationalization of water use represents about 36% of the total sample. Results revealed by using stepwise regression showed that three variables affected the degree of implementations for the recommendations of the technical rationalizations of water use, and these variables explained about 51% of the total variance of the implementations for the recommendations of the technical rationalization of water use. Those variables were: farmland holding size, respondent attitude towards the extension activities, finally respondent degree of formal social participation.
اظهر المزيد [+] اقل [-]Effect of neem and willow aqueous extracts on fusarium wilt disease in tomato seedlins 1-induction of antioxidant defensive enzymes
2011
Farag, H.R.M. | Abdou, Z.A. | Salama, D.A. | Ibrahim, M.A.R.
. The effects of neem (Azadirachta indica) and willow (Salix babylonica) aqueous extracts on fusarium wilt disease in tomato seedlings were investigated. Four weeks old tomato seedlings were treated with 10% of either neem and willow aqueous extracts and then infected with Fusarium oxysporum after 4 days of treatment. The results showed that the percentage of disease incidence was increased in non treated tomato seedlings in time dependent manner and reached the maximum level (65%) after 6 weeks of infection. Treatments of tomato plants with neem and willow aqueous extracts reduced the percentage of disease incidence to the level of 25.5% and 27.8% after 6 weeks of infection respectively. The results show that infection of tomato seedling with Fusarium oxysporum led to many morphological and biochemical changes including, reducing the growth of tomato shoot and root, increasing the level of lipid peroxidation and marked increase in the activities of antioxidant defensive enzyme I.e. POX, CAT, and SOD. Treatment with neem and willow aqueous extracts significantly exhibited a growth promotion of tomato shoot and root in infected or non infected seedling. Moreover, application of neem and willow aqueous extracts with fusarium, significantly reduce the level of lipid peroxidation and induce high activities of antioxidant defensive enzymes after 3 and 7 days of infection. Electrophoretic pattern of POX demonstrated that Fusarium oxysporum caused up regulation of several POX isoenzymes. It could be concluded that neem and willow aqueous extracts reduced the disease incidence of fusarium wilt in tomato seedlings by increasing the activities of antioxidant defensive enzymes and decreasing the level of lipid peroxidation.
اظهر المزيد [+] اقل [-]Analytic study of short fiber content in Egyptian cotton
2011
Ebado, E.A. | Hassan, R.M.
The experiment was conducted through two successive seasons of 2008 and 2009 at El Bosaily farm, EI-Behira governorate at the North Coastal of the Nile Delta, in Egypt. This work aimed to study the effect of three green-house covers (polyethylene sheet, white and black net) and three irrigation levels 180%, 100% and 120% of the potential evapotranspiration estimated according to class A pan equation (ET,)], applied by drip irrigation system, on plant growth and crop yield of Cucumber (Cucumis sativus L.. cv. Reda F1). The experimental design was split- plot with three replicates. The results showed that white net green-house cover optimized growth and yield of cucumber plant. White net cover treatment recorded the highest vegetative growth (plant height, number of leaves, total leaves area, total fresh and dry weights), and significantly increased total yield. The highest vegetative growth was obtained by 100% ETo compared to 80 and 120% ETo treatments. The interaction among water treatment and green-house cover indicated the highest vegetative growth and crop yield were obtained under white net cover with 100% ET,.
اظهر المزيد [+] اقل [-]Zinc and manganese sorption behavior by natural zeolite and bentonite
2011
Iskander, A.L. | Khald, E.M. | Sheta, A.S.
Understanding the sorption process in natural zeolite and bentonite is necessary for effective utilization of these minerals as nutrient adsorbents and on the other side for controlling release of plant nutrients. This research was undertaken to characterize the ability of natural zeolite and bentonite minerals to adsorb and release zinc and manganese. The potentials for sorption of these ions were evaluated by applying the Langmuir and Freundlich equations. The results showed that Langmuir constant (maximum adsorption (b mmol kg-1)) of both Zn and Mn were for bentonite zeolite While the [binding strength values (k in L.mmol1 for zeolite bentonite Zn in case of zeolite showed the lowest desorbed percentage particularly at high levels of sorbed Zn. Only, 74.7 % is readily extractable by DTPA after three successive extractions leaving, 25.3 % Zn retained by the mineral. In case of bentonite, 82.26 % of sorbed Zn is readily extractable by DTPA after three successive extractions leaving, 17.74 % Zn retained by the mineral. In case of Mn, 84.63% of Mn sorbed by zeolite is readily extractable by DTPA after three successive extractions leaving, 15.37% Mn retained by the mineral. In case of bentonite, 89.79 % of adsorbed Mn is readily extractable by DTPA after three successive extractions leaving, 10.21 % Mn retained by the mineral. This finding may reflect clearly the possibility of using natural zeolite and bentonite as a slow release fertilizer for Zn and Mn and on the other hand preventing soil pollution with heavy metals.
اظهر المزيد [+] اقل [-]Study of genetic relationship between some olive varieties in gellin gene bank
2011
Moustaf, N. | Hamed, F. | Lawand, S.
Olive tree (Olea europaea L.) is one of the most important fruit trees, there is a lot of varieties with the possibility of mislabeling, homogenouses and synonyms, which makes major troubles when having plant material for propagation and breeding programs. In this search, 12 olive varieties (Maw! Istanbul!, Khilkhali Khishen, Dan, Mniekri, Adkam, Doaibli, Mot, Khilkhali Saghir, Karamani Modabal, Mawi abo Shokeh, Sourani, and Abo Shokeh), cultivated in ACSAD Gene bank in Gellin, were characterized by ISSR molecular markers to determine the relationship between these varieties. Depending on quantitive traits the results indicated that these varieties are so close to each other's, ranged from 60% and 85%. It was noticed that Mneikri was apart from the other varieties in its traits, (polymorphic rate was 92.94%).
اظهر المزيد [+] اقل [-]DESIGNING AN INTEGRATED COMPUTER PROGRAM FOR VEGETABLE PRODUCTION IN THE KINGDOM OF SAUDI ARABIA
2010
R.A Bayoumi | Atta H.M. | El-Sehrawey M.H. | Selim Sh.M. | El-Hemiany A. | Abdullah Alsadon | Abdulrahman Alazba | Ibrahim Alshahwan | Abdulrahman Aldawood | Safwat Khalil
Vegetable production provide great value in the agricultural production sector in the Kingdom of Saudi Arabia. Growers and agricultural engineers need a comprehensive database in Arabic lan-guage that can be available for use any time any where. Therefore, this research project was initiat-ed. The computer program was developed using Visual Basic Net 2005 which is one of the ad-vanced visual programming languages. We took into consideration easy usage and coherence be-tween all program components. Main results in-clude computer program with the data base, which includes: vegetable crops, diseases, insect pests and other pests that attacks vegetable crops, management tactics, cultural practices, irrigation requirements, planting dates, data search. Fur-thermore, field trips have been carried out to some vegetable farms in all the Kingdom regions. A digit-ized map of the Kingdom has been added to the program in addition to crop water and heat re-quirements. Various search capabilities have been developed in the program. After the completion of the program build up, verification trips have been carried out for five regions in the presence of farm-ers and extension specialists of the different direc-torate of the Ministry of Agriculture to test the accu-racy of steps used in the program. A manual for the computer program as well as leaflet on pro-gram set up and usage have been included. It is recommended to make this program available at the internet and distribute copies to the Ministry of Agriculture and its directorates as well as farmers.
اظهر المزيد [+] اقل [-]COMPARATIVE STUDIES BETWEEN SOME SESAME CULTIVARS GROWN UNDER DIFFERENT EDAPHIC AND CLIMATIC CONDITIONS
2010
Two successive field experiments were carried out during two seasons (2006 and 2007) at three Agricultural Experimental stations of Desert Research Center (DRC) in three locations: El-Maghara, El-Wadi El-Gedeed and Maryout to evaluate variation, mean performance and stability parameters of four diverse sesame cultivars. Also, study the oil content, physical and chemical properties, fatty acids composition of oil and proteins patterns in seeds of the tested cultivars (Shandaweel 3, Toushki 1, Giza 32 and Taka 3). The results obtained could be summarized in the following categories:- Wide range of variability between locations and high genotypic differences were detected. The genotype x environment interaction was significant and a major portion of this was accounted by the deviation among source of variations. Hence, the genotypes tested had a wide diversity and ranked differently among locations and seasons. The average plant height, number of branches/plant, number of capsules/plant, 1000-seed weight, grain yield/plant, grain yield/feddan and oil yield/feddan were recorded under El-Wadi El-Gedeed, El-Maghara and Maryout locations. Toushki 1 recorded the highest values across different locations for Number of capsules/plant (46.21), number of seeds/plant (47.27), seed yield/plant (14.76 g.), seed yield/feddan (333.84 kg.) and oil yield/feddan (168.56 kg.). El-Wadi El-Gedeed location is considered the best location for most studied traits except for number of branches/ plant. On the other hand, Maryout location (calcareous 34% CaCo3) recorded the lowest values for all traits under study; such findings may be due to the differences between soil and irrigation water types. Stability parameters were fitting together in determining the stable genotypes Toushki1, Shandaweel 3, Giza32 and Taka3 overall tested environments. Genotypes varied in their calculated bi values as well as S2di . Toushki 1 is the most stable genotype across different environments and for all traits under study except for number of capsules/plant. However, genotypes produced higher yield such as Toushki 1 and Shandaweel 3 showed below average stability and were well adapted for El-Wadi El-Gedeed conditions. Oil content was increased while protein content was decreased significantly in seeds of Shandaweel3 and Toushki1 under El-Wadi El-Gedeed location. However, acid value was decreased for all cultivars except Taka 3 under El-Wadi El-Gedeed location at zero and 6 months of storage. On the other hand, the oil of all sesame cultivars which grown under El-Wadi El-Gedeed location had a higher iodine value than oil of the same cultivars under El-Maghara location. In
اظهر المزيد [+] اقل [-]SELENIUM INDUCES ANTIOXIDANT DEFENSIVE ENZYMES AND PROMOTES TOLERANCE AGAINST SALINITY STRESS IN CUCUMBER SEEDLINGS (Cucumis sativus)
2010
Se, Selenium; ROS, Reactive oxygen species; APX, Ascorbate peroxidase; CAT, Catalase; PAL, Phenylalanine ammonia-lyase; EDTA, Ethylenediamine tetra acetic acid; MDA, Malondialdehyde; POD, Peroxidase; PVP, Polyvinylpyrrolidone; SOD, Superoxide dismutase; TBA, Thiobarbituric acid; TCA, Trichloroacetic acid; NBT, Nitroblue tetrazolium; P5CR, ∆1-Pyrroline-5-carboxylate reductase; P5CS, ∆1-Pyrroline-5-carboxylate synthetase. OAT, Ornithine-δ-aminotransferase; P5CDH, ∆1-Pyrroline-5-carboxylate dehydrogenase and PDH, Proline dehydrogenase; Poly acrylamide gel electrophoresis (PAGE) ABSTRACT Selenium (Se) is not an essential nutrient for higher plants. Although, it is able to induce stress tolerance in many plant species. The present study was carried out to investigate the ability of Se to promote the tolerance of cucumber seedlings to salinity stress and to identify some biochemical parameter associated with Se–induced resistance in cucumber seedlings. Plants were irrigated with 2000 ppm NaCl after treatment with 1ppm Se for two weeks and samples collected after 7 days from started salt-treatment. The biochemical changes due to treatment with Se and /or NaCl were monitored by determination of lipid peroxidation (LPO), proline, phenolic compounds and percentage of electrolyte leakage (EL) from plant tissues. Moreover, the activities of peroxidase (POD), ascorbate peroxidase (APX), catalase (CAT), superoxide dismutase (SOD) and phenylalanine ammonialyase (PAL) were determined. The treatment of cucumber seedling with salinity (2000 ppm NaCl) in the presence or absence of selenium caused a remarkable elevation in free proline concentration and the level of phenolic compounds. Salinity stress caused a high level of lipid peroxidation which led to increase the percentage of electrolyte leakage from plant tissues. Se treatment caused a significant reduction in electrolyte leakage and malondialdehyde concentration of cucumber seedlings. The specific activities of antioxidant enzymes (POD, SOD, and APX) and PAL were significantly increased by the treatment with NaCl. Also, Se caused a significant elevation in the specific activities of POD, CAT, SOD, APX and PAL in cucumber seedlings grown under salt stress condition. On the other hand, Se caused a significant decrease in SOD activity in cucumber seedlings grown in non-salty condition. The isoenzymes pattern of POD demonstrated that peroxidase was up-regulated by Se either in control or NaCl-treated seedlings. The results concluded that Se induce six POD isoenzymes in cucumber seedlings. Se reduces and overcomes the oxidative injury caused by salinity stress. Moreover, the protective effect of Se against salinity stress may be carried out through a mechanism included activation of PAL which is responsible for phenolic compounds biosynthesis. The accumulation of these phenolic compounds in Se-treated seedling leads to a high activities of antioxidant defensive enzymes and increase the tolerance level towards salinity stress.
اظهر المزيد [+] اقل [-]