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النتائج 21 - 30 من 46
MYCOBIOTA OF SOLARIZED AND UNSOLARIZED CUCUMBER SOILS AND ROLE OF SOLARIZATION IN CONTROLLING OF SCLEROTINIA SCLEROTIORUM (LIB.) de BARY UNDER GREENHOUSE CONDITIONS
2007
M Ibrahim | A Abdel-Azeem
Soil mycoflora play an important role in agri-cultural economy of a country. The current study was made to have the knowledge about soilborne fungi associated with cucumber crop in solarized and unsolarized soils. Solarization exerted various effects, some of which are biological, others are chemical and still others are physical. All together these changes affected directly or indirectly the mycoflora of the soil, especially the soilborne pathogenic ones. Forty-nine fungal species belong to thirty genera have been isolated from solarized and unsolarized soils. The diversity as well as the count was greatly affected by solarization. By comparison of the species lists of the fungal flora of solarized and unsolarized soils it was evident that soil fungi behave differently toward soil solar-ization, while some new species developed e.g. Absidia, Acrophialophora, Talaromyces, Glio-cladium, some remained unaffected e. g. Aspergil-lus, Penicillium, Chaetomium, Botryotrichum, still others disappeared e. g. Acremonium, Cephali-ophora, Eurotium and others. Regarding solariza-tion for controlling white cucumber rot caused by Sclerotinia sclerotiorum, the obtained data clearly show that solarization had led to a marked in-crease in the number of healthy plants up to 72.5%.
اظهر المزيد [+] اقل [-]A PRELIMINARY SURVEY OF THE HOVERFLIES INSECTS (SYRPHIDAE, DIPTERA) IN DEIR-EZZOR, EASTERN SYRIA FAUNISTICS STUDY
2007
M Idraw
The hoverflies insect species are considered the most economic pollinators of various flowers, the adult visitors feed on nectar and pollen. Many of syrphid survivors are voracious aphid feeders in their larval instars and are considered greatest bio-control agent. They are beneficial insects when estimating the damage of pest control is consid-ered. In spite of their great economic importance, no progress has been estimated on taxonomy and biology of these insects in Syria. A surveillance studies of such flies were carried out in three loca-tions (Agroecosystems) in Deir-Ezzor, Eastern Syria during March-July 2006, based on number of captured adults. Yellow dish traps were used, and 12 spieces were identified and counted. This study will be an applicable addition to the availa-ble knowledge about the Syrian fauna.
اظهر المزيد [+] اقل [-]EFFECT OF CROP ROTATIONS AND NITROGEN FERTILIZATION ON YIELD, YIELD COMPONENTS AND ASSOCIATED WEEDS IN COTTON
2007
S Toaima
This study was conducted at Sids Experimental Research Station, Beni Suief Governorate, starting from year 2000 to study the effect of rotation dura-tion (every year, 2- year rotation and 3- year rota-tion) and nitrogen fertilizer rates; 45, 60 and 75 kg N/ fed on growth, yield components and yield of cotton, as well as associated weeds. A split plot design was used with four replicates. The data indicated that crop rotation had significant effect on plant height, number of fruiting branches/ plant, number of open bolls, seed cotton yield/ plant and seed cotton yield/ fed. Seed cotton yield/ fed was increased by 10.99 and 23.62 % when 2-year and 3-year rotations were applied, compared to 1-year rotation (average of both seasons). In-creasing N- fertilization up to 60 kg N/ fed caused significant increases in all studied traits. The best estimate of yield (Y) plotted against N rate (X) for annually rotated cotton was the linear equation of Y =2.44 + 0.074x (R2 =0.81). Two years rotation showed a quadratic association with increasing the N rate, R2 = 0.86 and 0.88, respectively. The high-est values of total fresh weeds were 2.85 and 2.60 kg/ m2 (broad and grassy weeds) when 1-year ro-tation was applied, while the lowest values were 1.50 and 1.35 kg/ m2 when 3-year rotation was applied in the first and second season, respective-ly.
اظهر المزيد [+] اقل [-]EFFECTS OF PLANTING DATE ON WATER REQUIREMENTS OF MAIN VEGETABLE CROPS IN SAUDI ARABIA
2007
J Basahi
The effects of planting date on the evapotran-spiration (ETC) were studied for Tomato, Egg-plant, Squash, Cucumber, Carrot, Potato, Onion, and Watermelon, in Riyadh, Makkah, Njran, Al-Qassim, Eastern region, Tabuk, Al-Jouf, Aseeir, Al-Madenah, Hail and Jazan Regions based on the crop pattern in each region. The ETC of each crop was estimated based on Penman-Monteith Equa-tion. The results showed that the ETC for crops planted in January, February, March, April or Maywere higher than those crops planed in September, October, November, or December. The average ETC was higher when planting date was closer to summer months (June, July and August). Also, the results showed differences in ETC among the dif-ferent regions. The ETC in Al-Madenah region was higher than the other regions for Tomato and Eggplant. While, Riyadh region had the highest ETC values compared with the other regions for Squash, Cucumber, Carrot, Potato, Onion, and Water melon
اظهر المزيد [+] اقل [-]RAPID ESTIMATIONS OF BIOLOGICAL FINENESS OF COTTON FIBERS USING MICROMAT DATA
2007
A Mohamed | M Sief | S El-Hariry
Rapid estimations of diameter minus lumen(D-L), and outer perimeter of cotton fibers (P) inmicrons, as a biological fineness of Egyptian cottoncould be calculated with satisfactory levels ofaccuracy from hair weight (H.W) in m/tex andmaturity ratio )MR) obtained from Micromat data(new F/MT instrument), using the following equations:2Circularity x 3.14 x 1.52Hs (Standard finenessDiameter (microns) or Final format (D) (microns) = 1.205 HsorCircularit y × 1.524 x 3.14 x HsPerimeter (microns) or Final format (P) (microns) = 3.7853 HsResults of the current study suggested thatmore attention should be focused on meaning andmeasurements of the three values of biologicalfineness (i.e.) diameter (D), perimeter (P) (microns)and standard fineness (Hs) m/tex. whichcan be derived from the data obtained from Micromatinstrument.
اظهر المزيد [+] اقل [-]DEVELOPMENT OF VOLATILE COMPOUNDS OF AVOCADO AND CASIMIROA DURING FRUIT MATURATION
2007
Magda Abd El-Mageed
Avocado fruits (Persea americana Mill) cv. Fuerte and white sapote (Casimiroa edulis) cv. Rotaceae cultivated in Egypt were collected at different maturity stages:green mature,commercial ripe and over ripe stages. The headspace volatiles of each maturity stage was isolated and subjected to gas chromatography- mass spectrometric analy-sis. A total of 43 components were identified in avocado aroma including; terpenes (15), esters (8), aldehydes (8), alcohols (6), ketones (2), thiazoles (l), pyridines (1), toluene and acetic acid, where as 18 compounds were, identified in casimiroa aro-ma, they contained (4) esters, (6) alcohols, (4) aldehydes, (3) terpenes and (1) ketone. Ethanol (Z)-3- hexenol and (E)-2- hexenal were the major constituents in green and ripe fruits of avocado whereas they decreased at the final stage of matu-ration. Over ripe avocado fruits had the highest content of esters (ethyl ethanoate, ethyl acetate and methyl propanoate) and terpenoides especially d-limonene and z-nerolidol. Esters and alcohols comprised more than 85% of the total concentra-tion of volatiles in casimiroa fruits during three stages of maturation. The highest content of ethyl butanoate (sweet and fruity aroma) and ethanol revealed the most prominent effect on consumer acceptability of the cosimiroa flavour attributes. It is obvious that maturation of the fruits was associ-ated with remarkable changes in the volatiles that mainly affect their flavour.
اظهر المزيد [+] اقل [-]EFFECT OF GROWTH TECHNIQUES (PRUNING METHOD) ON THE PRODUCTION OF CUCUMBER GROWN IN GREENHOUSES
2007
AL-Obeid, S. S.
The present study was carried out to investi-gate the effect of pruning method on growth and production of cucumber (hybrid Aula) grown in greenhouses for 2004 and 2005 growing seasons. Three types of pruning were used : system of prin-cipal stem, system of secondary branchs, and mixed system (principal stem + secondary branchs). The results show the following points * Effect of mixed system is distinguish on early and total production in comparison with the other used methods which present a comparable production. * Failing growth and production of mixed system at the end of season compared with two other used methods. This experience allows to suggest * Use of mixed system necessitate the regular pruning of plants for avoid the physiological fail and the bad morphological and physiologi-cal characteristics of fruits. * Possibility of application the system of principal stem and avoid the system of secondary branchs with the necessity of knowledge the type of branch of varieties for avoid the tardy production
اظهر المزيد [+] اقل [-]EFFECT OF ETHYL SALICYLIC ACID VAPOUR ON SPROUTING AND ROTS INCIDENCE OF POTATO TUBERS UNDER LONG-TERM STORAGE(a)
2007
Mostafa M | E. Gado
The effect of exposing of potato tubers cv. Di-amond to ethyl salicylic acid (ES) vapour for dif-ferent doses and different periods of exposing on rots incidence and sprouting of tubers under long term storage was studied. Expose of tubers to high doses of vapour (resulted from evaporation of 0.5 or 1 ml/ liter space) for 6 h led to appear a very strong harmful effect on exposed tubers stored for 4 months. All tubers were decayed, collapsed and severely infected by rot pathogens. Expose of tu-bers to middle dose (0.25 ml/liter space) for 6, 12, 24, or 48 h then stored for 4 months at ambient temperature showed variable effects. Six or 12 h exposing led to slight reduction of rot incidence but it had not effect on sprouting in comparison to non-exposed tubers. On the other hand, exposing, for 24 or 48 h suppressed sprouting completely and reduced to very great extent rots incidence (%). Storage of tubers exposed to 0.25 ml/ liter for 24 h at high relative humidity (~90%) or under cooling (6-8 Cْ ) did not cause any reduction in compound efficiency. Expose of tubers to low dose of ES vapour (0.125 ml/ liter space) for dif-ferent periods showed that exposing for 6 or 12 h led to stimulatory effect on sprouting without ef-fect on rots incidence. Twenty four hours exposing led to decrease rots incidence and sprouting.These results clearly indicated that ES vapour had variable effects on exposed tubers depend upon dose and period of exposing.
اظهر المزيد [+] اقل [-]COMPARATIVE STUDY OF SOME WEED CONTROL TREATMENTS ON DIFFERENT WEEDS GROWN IN ANNA APPLE ORCHARDS
2007
I El-Metwally | Omaima Hafez
This study was carried out during two succes-sive seasons 2005 and 2006 on Anna apple trees budded on Balady apple rootstock, grown in sandy soil at (4 x 4m) apart under drip irrigation system, in a private farm at El-Khatatba, Monofia Gover-norate. A comparative study of some weed control treatments have been studied on Anna apple trees with its associated weeds. The tested weed control methods were using different colours of polyeth-ylene for mulching (green, blue, red, black and transparent), rice straw mulch, hand hoeing twice and two herbicides (Glyfosinate and Glyphosate) comparing with unweeded (control). All weed control treatments revented a significant reduction in fresh and dry weight of annual broad-leaved weeds, annual grasses, perennial and total weeds as compared with un weeded. The most effective treatments in decreasing fresh and dry weight of annual broad-leaves weeds were rice straw mulch-ing, followed by black polyethylene mulch and Glyfosinate. While, rice straw, black polyethylene and Glyphosate treatments were the most effective in decreasing fresh and dry weight of grass and total weeds. Also, the highest decrement in fresh and dry weight of perennial weeds were obtained by rice straw mulching and Glyphosate treatments. Moreover, results showed a remarkable improve-ment in growth, nutritional status of apple trees and yield (kg/tree). Also, physical and chemical properties of the fruits were improved. The most pronounced treatment developed under such study on the growth reduction of different grown weeds, meanwhile increased the apple tree growth, fruit yield associated with higher fruit quality was in rice straw mulching, black polyethylene mulching, Glyphosate treatments followed by hand hoeing twice treatment.Finally, it could be concluded that soil mulch-ing with rice straw can be used as a method for weed control in apple orchards. This method de-veloped such advantages over herbicides, polyeth-ylene mulch and hand hoeing in this concern. The possibility of using rice straw mulch for their many positive effects such as low coasts, in har-mony with ecosystem without no harmful residual effect especially for exported fruits and for pro-ducing safe fruits for human nutrition. In addi-tions, soil mulch with rice straw improving growth, leaves mineral contents as well as pro-duced higher yield and better quality of apple fruits.
اظهر المزيد [+] اقل [-]EFFECT OF PHOSPHATE ROCK AND TRIPLESUPERPHOSPHATE ON GROWTH AND LEAF N, P AND K CONTENTS OF GROUNDNUT (ARACHIS HYPOGAEA L.) GROWN ON A CLAY SOIL
2007
M Elsheikh | A El-Tilib | E Elsheikh | A Elkarim
A pot experiment was carried out to investigate the agricultural value of a local phosphate rock (PR) as a source of plant phosphorus compared with that of the currently imported triplesuper-phosphate (TSP) .The PR was applied at the rate of 0, 55, and 110 kg P2O5 /ha and the TSP was at the rate of 0, 45 and 90 kg P2O5 /ha. The growth and leaf contents of N, P and K of groundnut (Arachis hypogaea L.) grown on a clay soil were measured. The experiment continued for two sea-sons. Phosphatic fertilizers are of low recovery; therefore, they can remain for the next crop. Thus, the pots of the first season were set to study the residual effect of phosphorus in the second season. The results indicated that PR and TSP significant-ly (P>0.05) increased dry weights of shoot and root, leaf contents of N , P and available soil phosphorus. However, plant height was signifi-cantly increased by TSP only. The leaf content of K was neither affected by PR nor TSP application. The results showed a positive effect of the residual PR and TSP on the measured parameters. Moreo-ver, the results revealed that the plant measure-ments obtained from PR treatments were compa-rable to those obtained from TSP treatments which indicate that PR can be used as a potential source of phosphorus fertilizer.
اظهر المزيد [+] اقل [-]