خيارات البحث
النتائج 1071 - 1080 من 1,443
SOME FACTORS AFFECTING SUCCESSFUL APIS MELLIFERA QUEEN REARING IN SOHAG
2010
I.M El-Metwally | R.M.H Tagour
Studies were accomplished to identify the important factors affecting successful virgin queens production in Sohag during 2007 and 2008 years. In order to find out the best teaching for rearing virgin queens by grafting method. Markedly differences in the mean number of virgin queens between single and double grafting methods, specially in spring and autumn seasons; in spring mean number of accepted cells of 43.77 with 37.66 emerged queens and 49.85 with 47.07 emerged queens were obtained when single and double grafting were used methods respectively. Spring season was favorable for queens rearing, followed by autumn and summer, while winter season came the latest. There was a clear relationship between larval age at grafting and the larval acceptance, one day old worker larvae gave the highest number of virgin queens emerged. On the other hand, the queen must be removed outside the hive 48 hrs before starting larval grafting to obtain the highest numbers of accepted queen cells. In general, double grafting, situating the cell cups frame in the hive center of the hive and fitting the cell cups on the top and bottom bar, gave the best method for queens acceptance and queens production. However, cell cups fitted on the edges of the bars were successfully reared when ambient temperatures were high in spring season, but queen cells in the center of the hive's brood nest were correlated with higher temperature and had a greater chance for emergence.
اظهر المزيد [+] اقل [-]TOLERANCE OF HONEY BEE COLONIES TO VARROA DESTRUCTOR (ANDERSON AND TRUEMAN) AND THE ECONOMIC THRESHOLD OF THE PARASITE IN THE CENTRAL REGION OF KINGDOM OF SAUDI ARABIA
2010
. Omran Nageh, S.M | Mabrouk ; M.S.O. | Mohanna K.M.
Experiments were carried out on honey bee colonies (Apis mellifera) during the winter of 2008 and spring of 2009 using colonies wintered with five levels of varroa infestation (0.0, 3.8, 9.0, 13.1 and 22.9%) in the Central Region of the kingdom of Saudi Arabia. The goal of the present work is to determine varroa treatment thresholds and colony collapse level. Response variables examined included varroa mite infestation level (%), cm2 of brood number of frames of brood, number of frames covered with adult honey bees and mites recovered on sticky boards. The data obtained reveled that no significant differences were noticed in cm2 of brood, number of frames of brood, and number of frames of bees in colonies (range of 0.0 to 9.0% varroa infestation or 0.0 – 0.9 mites/bee). Colonies with 13.1% infestation (0.13 mites/bee) exhibited a significant reduction in all measures of performance. The present results suggested that honey bee colonies can tolerate a level of 9.0% varroa infestation (0.9 mites/bee) during the winter without evidence of colony injury. It also suggested that 13.1% infestation (0.13 mites/bee) is the colony collapse or economic injury threshold in the Central Region of the Kingdom of Saudi Arabia. Also colonies with 12.3 or more mites falling on sticky boards after 48-hour period were likely to have lower populations of bees and brood the following spring.
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 [-]EFFECT OF PHOSPHORUS FERTILIZER TREATMENTS ON INCIDENCE OF FUSARIUM ROOT-ROT/WILT DISEASE COMPLEX, AND ON YIELD COMPONENTS OF LUPINE, CHICKPEA AND LENTIL CROPS
2010
A Elhassan | A El-Tilib | Ibrahim ; H.S. | A.H. Awadelkarim
In greenhouse and field experiments, conducted in two successive winter seasons 2007/2009 the effect of phosphorus fertilizer treatments on incidence of wilt disease of lupine, chickpea and lentil, as well as yield and yield component was studied. Application of Phosphorus fertilizer (100 and 200 kg/fed; as super phosphate (15.5% P2O5) before planting) caused a reduction in incidence and severity of wilt diseases on plants of the three legume crops either in greenhouse and field experiments. In field experiments, results indicated that the most effective treatment was phosphorus at 100 and 200 kg / fed) respectively, which reduced the wilt diseases. Phosphorus fertilizer significantly increased yield characters i.e., plant height, number of branches, number of pods, seeds yield / plant and weight of 100 seeds.
اظهر المزيد [+] اقل [-]DESIGNING AN INTEGRATED COMPUTER PROGRAM FOR VEGETABLE INSECT, NON INSECT PESTS AND DISEASES AFFECTING VEGETABLE CROPS
2010
Abdulrahman Aldawood | Ibrahim Alshahwan | Abdullah Al-Sadon | Abdulrahman Al-Azba | Omar Abdalla | Alshamy Adam | Ali Almasrahy
The major vegetable crop production in the Kingdom of Saudi Arabia require easily produced sources of related information. However, there is a lack of such studies that lead to the use of com-puter programs or geographical information sys-tems in developing an electronic source for these extension, research, and scientific data. Farmers and agricultural engineers need a comprehensive database regarding insect pests, non insects pests, and diseases infecting vegetable crops in Saudi Arabia in Arabic language. Therefore, this project has been executed to design a complete database of such information. Included in this software are colored photographs, which will help users to get acquainted with methods of manage-ment of these pests and diseases. A data sheet has been designed to collect field information for each vege-table crop, including its pests and dis-eases, through field trips for many farms in all the 13 agricultural regions of Saudi Arabia. This field information has been compiled with what has been published in related scientific references. Upon completion of this program, confirmatory trips for five regions had been made in order to meet with farmers, agricultural engineers, and extension agents who are in agricultural branches of the Min-istry of Agriculture in these visited regions. The objectives of these trips were to get feedback about this program. Finally, an elaborate imple-mentation guide was prepared under the title "De-signing an integrated computer program for vege-table cultivation in The Kingdom of Saudi Arabia." Also, an attached manual, regarding the compo-nents and the operation of this program, was made. All of these materials have been distributed to farmers and interested people in the agricultural sector
اظهر المزيد [+] اقل [-]FORMULATION AND EVALUATION THE NEMATICIDAL ACTIVITY OF CERTAIN PLANT OILS AGAINST CITRUS NEMATODE Tylenculus semi-penetrans
2010
, A.M.A El-Kady | S. Ibrahim Hala | . Farag E.M.A | El-Torkey H.M.
Four plant oils namely Barka, Sesam, Garlic and Almond were prepared as emulsifiable concentrate (EC). Polyethylene glycol 600 dioleate (PEG 600 DO), Toximol R and Toximol H were used as emulsifiers while xylene and toluene used as solvents. Four formulations only passed successfully (F1, D2, C3 and E5) in thePhysico-chemical properties according to the standards of WHO. The results indicated that the successful prepared formulations showed different degrees of effectiveness against second stage juveniles of Tylenculus semipenetrans under laboratory conditions. Second stage juveniles seem as paralyze at 24 hrs, whereas this effect disappears completely after 72 hrs in case of Almond and Barka. On the other hand, the effect of Sesam and Garlic showed a slight effect at 24 hrs and increased gradually to give highly effectiveness after 72 hours. According to EC50 values at 72 hrs, Garlic was more effective than Sesam. The respective EC50 values were 0.6 and 2 mg/ml. These results emphasized the promising effect of certain plant oil formulations including Garlic and Sesam oil against pathogenic nematode, and that such formulation might be used for nematode control in small areas, as gardens and plant nursery.
اظهر المزيد [+] اقل [-]IMPROVEMENT PROPERTIES OF WHEAT FLOUR USING MICROWAVE
2010
Ayman Soliman
In view of balady bread in Egypt is considered as backbone in diets, accordingly, in this study wheat flour (82%) extraction treated by microwave at 2,4 and 6 minutes, that target to modify starch wheat flour by heating. The rheological properties were studied by using farinograph and extensograph apparatus. Falling number and amylose percent were determined. Balady bread samples were sensory evaluated and staling rate was evaluated. The wheat flour, crust and crumb layers of balady bread were examined by scanning electron microscope (SEM). The results of farinograph indicated that, water absorption arrival time, dough development time and dough stability increased while dough weakening decreased in wheat flour treated by microwave compared with wheat flour untreated (control). The results of extensograph revealed that, dough extensibility, resistance to extension and dough energy increased while proportional number decreased in wheat flour treated by microwave compared with control. Falling number decreased while amylose percent increased when microwave treatment increased from 2 to 6 minutes. Sensory evaluation showed slight decrease in values of both color crust and color crumb while, values of both taste and flavor slightly increased but not significantly different, meanwhile, values of crumb distribution significantly increased in balady bread samples prepared from wheat flour treated by microwave compared with balady bread prepared from untreated wheat flour (control). Wheat flour treated by microwave led to delay staling of balady bread and imilorated freshness of balady bread. The examination by scanning electron microscope (SEM) showed that average size of starch granules increased from 26.10 mm in untreated wheat flour (control) to 29.37 mm in treated wheat flour by microwave at 6 minutes.
اظهر المزيد [+] اقل [-]EFFECT OF GIBBERELLIC ACID ON THE PERSISTENCE OF CERTAIN PESTICIDES ON/IN GRAPE FRUITS
2010
Fergani, M. A. | El-Habbal S. | El-Temsah E.
Recommended application was done by spray regime for two pesticides, namely diniconazole, fenitrothion and a plant growth regulator (gibberellic acid) and their mixtures. Their residues were determined after different successive treatments in and on grape fruits in two consecutive years. The initial deposits of the fungicide diniconazole when used alone were 0.49 and 0.50 ppm for 2006 and 2007, respectively. While the initial deposits of fenitrothion reached to 11.35 and 11.19 ppm for the same interval, respectively. Initial deposits of the plant growth regulator gibberellic acid were 30.52 and 30.42 ppm for the same period, respectively. After mixing the tested pesticides and the plant growth regulator, the initial deposits loss reached 38.77 and 42.0 % for diniconazole, 43.08 and 48.16 % for fenitrothion and 6.88 and 7.00 % for gibberellic acid for the same seasons, respectively. A significant degradation was recorded with the mixture of the two tested pesticides and plant growth regulator compared with that occurred when pesticide was used alone at the two studied seasons.
اظهر المزيد [+] اقل [-]IMPROVEMENT OF CANOLA SEED YIELD AND QUALITY USING SULPHUR AND IRRIGATION INTERVALS UNDER DIFFERENT IRRIGATION WATER SALINITY LEVELS
2010
G Al-Solimani | F El-Nakhlawy | M Al-Morshdy
This investigation was conducted at Hada Elsham Experimental Research Station, King Abdul- Aziz University during 2007/2008 and 2008/2009 seasons, to study the effects of two irrigation water salinity levels (1200 mg/L and 10000 mg/L), three irrigation water intervals (3, 6 and 9 days) and three sulphur fertilizer rates (0.0, 4.0 and 6.0 t/ha) on seed yield, yield components and seed quality of canola, Pactole cv. The obtained results showed that seed yield kg/ha was significantly increased under the 1200mg/L irrigation water and 6t/ha of sulphur more than the seed yield/ha under the effect of 1200 mg/L irrigation water with 4 t/ha sulphur or 10,000 mg/L irrigation water with 6t/ha sulphur with no significant differences between the two later treatments. Irrigation every 3 days significantly dominated over the irrigation every 6 or 9 days on seed yield and yield components. Irrigation with 10.000 mg/L salinity water significantly decreased No. of branches /plant, No. of fruit/plant and seed weight/ plant. Besides, Protein content of the seed as well as oil content increased as water salinity increased in both seasons. As sulphur fertilizer rate increased seed yield, yield components protein and oil contents of seed significantly increased, in the two studied seasons.
اظهر المزيد [+] اقل [-]EFFECT OF HEAT TREATMENT ON THE NUTRITIVE VALUE AND RESIDUES OF SOME SYNTHETIC PESTICIDES IN FRESH BOLTI FISH
2010
Khaled Al-Joumaa
Fresh Bolti fish (Tilpia nilotica) collected randomly from 9 different markets in Ismailia Governorate for evaluation the effect of grilled fish by the method used in grillrooms and houses on the concentration of pesticide residues found and the nutritive value. Results revealed that decrease in the estimated parameters i.e. moisture, crude protein, fat and ash by grilling, this decrease were 6.07, 2.63, 4.07 and 1.56%, respectively. On the contrary, carbohydrates behaved another behavior that there was an obvious increase ranged from 1.98% to 2.92%. Fresh and grilled fish were analyzed to detect 12 organochlorine (OC) and 7 synthetic pyrethroid (SP) pesticides with a mean level on a lipid basis. Gas Liquid Chromatography equipped with Electron Capture Detector GC-ECD was used to detect the contamination in the samples. The results showed that p,p'-DDE isomer was dominated over the other isomers in all analyzed fish samples, followed by a-isomer of hexachlorocyclohexane. The concentrations of OC residues were higher than SP pesticides in all fish muscles. Also, the fresh fish muscle recorded higher concentrations of the evaluated pesticides than the grilled one.
اظهر المزيد [+] اقل [-]