خيارات البحث
النتائج 481 - 490 من 1,443
Phytoremediation of Pb and Cd by Alfalfa (Medicago sativa L.): An Applied Study in the Presence of Lettuce Plants (Lactuca sativa L.)
2022
Manar Morsy | Mona Nossier | Abd Ellatif Elsebaay | Shaimaa Abd-Elrahman
A pot study was conducted to investigate the potential of alfalfa for phytoremediation of soil artificially contaminated with different concentrations of Pb and Cd and their combinations. Harvested plants were divided and used for two purposes: (1) separation into roots and shoots, which were digested to determine N, P, K, Pb and Cd concentrations, and (2) the use of fresh shoots to prepare alfalfa extract representing each treatment. Subsequently, lettuce seedlings were grown in the same pots with the same soil and without adding fertilizers; the alfalfa shoot extract prepared from each treatment was added to the treatment itself. Lettuce crops harvested after 67 days from transplanting were divided into roots and shoots which were digested to determine the previously studied elements. In addition, soil samples were collected after harvesting alfalfa and lettuce plants and prepared for chemical analyses. Results showed that alfalfa is an effective accumulator plant for the phytoremediation of Pb- and Cd-contaminated soils. In addition, using the alfalfa shoot extract to fertilize lettuce crops was beneficial to their growth without any risk of translocation of heavy metals. Thus, we recommend adding alfalfa to crop rotations, especially where soils are contaminated with heavy metals.
اظهر المزيد [+] اقل [-]Effects of Foliar Amino Acid and Vitamin Applications on Heat Stress, Production, and Quality of Lettuce Head Improvements
2022
ٌRabie Gomaa | Usama Elbehairy | Mohamed Elshenawy | Alaa El-din Tantawy
This study was conducted to investigate the effect of amino acid and vitamin foliar applications on improving iceberg lettuce (Lactuca sativa L.) production and quality during the summer. First, two hybrids (Patagonia and Bruma) were grown hydroponically in June 2018 and 2019. Then, for five consecutive weeks, plants were sprayed once a week with Stress Free (a commercial product comprising 0.5% vitamins [vitamin B complex/ascorbic acid] and 0.5% selenomethionine) at concentrations of 1.0, 2.0, and 3.0 g/L and Aminomad (20% free amino acids) at concentrations of 2.0, 3.0, and 4.0 cm3 /L. Investigations revealed that all plant growth aspects were positively improved with all foliar spray treatments than with the control. Furthermore, while mineral contents (nitrogen, phosphorus, potassium, calcium, and magnesium) showed positive responses to the applied treatments, the highest dose of amino acids showed the highest marketable and total yield effects among all foliar spray treatments with the Patagonia hybrid. However, the marketable and total yield of lettuce heads was lowest with the control treatment without spraying.
اظهر المزيد [+] اقل [-]Deficit Irrigation Technique to Improve Water Productivity of Avocado Grown on Mulched Sandy Soi
2022
Mostafa Sokkar | Eslam Ahmed | Ahmed Ibrahim | Manal Mubarak | Mona Nosseir
A field experiment was conducted in new reclaimed areas to improve avocado trees water productivity cultivated under deficit irrigation and mulching. The deficit irrigation treatments were 90, 80, 70, and 60% of reference evapotranspiration (ETo). Results revealed that The average water requirements during different avocado trees physiological growth stages were 613, 1509, 1755, 1391, and 632 m3 /fed for flowering to end of fruit set, fruit set to approximately 50% of the expected market fruit size, during the fruit growth stage, during the fruit ripening stage, and during the flower bud formation stage, respectively. These values represent approximately 10.4%, 25.6%, 29.7%, 23.6%, and 10.7% of the total yearly water requirement. The averages irrigation frequency were 2.45, 2.61, 2.72, 2.87, and 3.91day for 100, 90, 80, 70 and 60% ETo treatments, respectively. The highest crop water productivity value of 1.24 kg/m3 water was attained at 70% ETo followed by 1.18 kg/m3 water at 80% ETo while the least crop water productivity (1.06 kg/m3 water) was realized at 100% ETo. The crop water requirement of 5110 m3 /fed/year with high irrigation frequency is recommended for mulched sandy soil cultivated with avocado trees.
اظهر المزيد [+] اقل [-]AquaCrop Model Enhancement under Soil Mulching Practices Considering Soil Temperature Effect
2022
Sobhy Mahmoud | Yasser Arafa | Ahmed Abo El-Hassan abdel aziz | Abdel-Ghany El-Gindy
Soil temperature under mulching conditions has a significant impact on crop development, growth rate and other parameters. However, it is not included in the AquaCrop model. Thus, this study aims to improve the AquaCrop model performance for better simulation of soil mulches by considering the heat changing under mulch materials. The proposed modification is conducted through AquaCrop-Open Source software to identify the differences between the temperatures under the mulched soil and air temperatures. It will also help to describe them as additional heat units in specific growth stages. The field data used to evaluate the proposed model has previously been used to calibrate and validate the AquaCrop model in simulating melon growth under different irrigation treatments and soil mulching practices. The results show that the proposed model performs better than the original model in simulating mulched melon under different irrigation regimes. The root mean square error of biomass values was reduced under the modified model by 40%-75% under different irrigation treatments. Additionally, the coefficient of determination (R2) of the modified model slightly increased from the original one. Thus, the proposed model provides a more reliable and robust model.
اظهر المزيد [+] اقل [-]Design of Sprinkler Irrigation Systems Using an Expert System Program
2021
Mohamed Alashram | Khaled elbagoury | Said Shaaban | Ahmed abdel-aziz
In this research, a rule-based expert system named EFSIS-ES (Engineering Factors of Sprinkler Irrigation System -Expert System) had been built, verified and validated. Therefore, the aims of this research were to build, verify and validate an expert system for making a decision for the normal user to maximize system efficiency of sprinkler irrigation. The inputs data included location data, climate data, pump data, crop data, soil data and sprinkler system data. The outputs of the expert system were number of the sprinklers on a lateral, number of laterals in the irrigation system, length of each lateral, main line length, irrigation frequency, required pump power, total dynamic head (TDH) and pump discharge output. Results showed high correlation (R2 = 0.9927) between the EFSIS-ES program and the designed spreadsheet in regard to irrigation frequency. It could be indicated high correlation (R2 = 0.9999) between the EFSIS-ES program and the designed spreadsheet regarding pump power. The regression coefficient (R2) was 0.9983 between EFSIS-ES program and SSSDPS Expert regarding total dynamic head (TDH). It could be indicated high correlation (R2 = 0.9979) between EFSIS-ES program and SSSDPS Expert regarding pump discharge output.
اظهر المزيد [+] اقل [-]Improvement of Irrigation Efficiency by Developing Surface Irrigation System
2021
Marwa Mohamed | Mahmoud Hegazi | essam wasif | Osama Ahmed Bedir
The experiments were Carried out in Biahmu Village at Al-Fayoum Governorate, Egypt during the two winter seasons of 2018/2019 and 2019/2020, on wheat crop to (cv. Gemmiza 11) evaluate the traditional surface irrigation system "TSIS" and the improved surface irrigation system "ISIS"(terrace), under laser leveling with two slops (S1≈ zero% and S2 ≈ 3%). The evaluation parameters included; reduction in land loss "LL", the roughness coefficient of marwa-walls, water efficiencies (i.e., water conveyance efficiencies "WCE", water application efficiencies "WAE" and water storage efficiencies "WSE"), yield productivity "Yp", total applied water and water required, irrigation water productivity "IWP" and times of water advance, recession and opportunity. The results concluded that improving traditional marwa, led to reduction in land loss by 49.46% from the area of marwa, and "WCE" increased by 83.17% in improved Marwa "IM" the compare to Traditional Marwa "TM. It was observed that on the efficiency of water added to the field irrigated by "TM". The highest level of water productivity (1.79kg wheat/m3 water) was achieved in "IM" at a level of 3%. Advanced time "T.Adv" (min) decreased at 50, 50.77, 27.6, 20.75, and 17.17% and 30.9, 40.51, 22.8, 10.89 and7.05% for "TL and IL" by sloping to "S2".
اظهر المزيد [+] اقل [-]Reducing Fruit Sunburn and Splitting in Murrcot Tangarine Fruits by Using Silicate Application
2021
Farid Mohsen | Mohamed Ibrahim
This experiment was done during 2019 and 2020 seasons on 10 years old Murcott tangerine trees (Citrus reticulata, Blanco) grafted on Volkamer lemon rootstock and grown under drip irrigation system at 3 × 5 m apart at a private citrus orchard at Sharkia Governorate, Egypt. The treatments were, Control treatment (sprayed with tape water only), Potassium silicate at 0.6 % (6 ml/ l), Aluminum silicate (Kaolin) at 4 %, Potassium silicate at 0.3 % (3 ml/ l) + Aluminum silicate (Kaolin) at 2 %. The treatments were done at 3 weeks intervals from mid-May to mid-August. The spraying was over the whole tree (canopy and fruits). Generally, all silica treatments improved yield, fruit quality and reduced sunburned and splitted fruits. The combined treatment of kaolin at 2 % + potassium silicate at 0.3 % (3 ml/ l), was the best treatment. Where, it reduced the sunburned and splitted fruits and improved yield, fruit weight, fruit dimensions, peel thickness, TSS% in comparison with other treatments. It could be recommended as a treatment for Murcotte tangarine trees
اظهر المزيد [+] اقل [-]Efficiency of Three Bacterial Strains Against Tetranychus urticae Koch (Acari: Tetranychidae) Under Laboratory Conditions
2021
Heba Emam
This study was conducted to evaluate the efficiency of three bacterial strains Pseudomonas aeruginosa, Bacillus subtilis and Lysinibacillus spaericus against adult females of Tetranychus urticae Koch using spraying and dipping techniques with concentrations (101, 103, 105, 107 cfu. ml-1). The mortality percentages were calculated and numbers of each stages resulting from the live treated females were recorded. The symptoms that appear on treated female's mites as a result of death under laboratory conditions were recorded and photographed. The results revealed that, P. aeruginosa caused the highest mortality percentage of adult females T. urticae 100% after 72h at concentration 107 cfu. ml-1 by spraying application. Whereas the mortality percentage which recorded by the dipping technique was 54.58±1.71. B. subtilis also, was recorded increased the average mortality percentage of female T. urticae as it reached 73.33±2.67 in spraying technique compared 41.25±2.08 in dipping technique. While in L. spaericus recorded 62.08±3.41 mortality (%) in spraying technique but at dipping technique the mortality was 27.50±1.61. A sharp decrease was shown in number of stages resulting from lived treated females of T. urticae with P. aeruginosa by four concentrations 101, 103, 105 and 107 by using spraying technique and the life cycle was stopped at the larval stage only at concentration 101 and were not changed into the nymphal stage. While with dipping technique a slight increase in the average number of stages resulting from the adult living females treated with the previously aforementioned concentrations of bacteria P. aeruginosa. The present study cleared that application of bacteria strains on T. urticae adult females either by spraying or dipping techniques lead to some deformations such as, swelling of the body, then fluids exit followed by complete dryness of the body and forward protrusion of the podosoma region and finally death of the adult females
اظهر المزيد [+] اقل [-]Patterns and Determinants of Egyptian Consumption of Meat and Fish
2021
Awad Basiouny | Olfat melouk | Afaf Mohamed | Tamer Adlan
The study showed that the population, imports of red meat, and retail prices of red meat are the most important factors affecting the amount of red meat consumed during the study period. But the production of white meat, the population and the retail price of white meat are the most important factors affecting the amount of white meat consumed. As for the most important factors affecting the amount of fish consumed, they were represented in fish imports, national income, retail prices of fish and retail prices of white meat. The study also found that the meat group ranks first among the food groups, with a spending rate of about 27.4% and 28.19% of the total spending on food and drink in both rural and urban areas, respectively. While fish ranked sixth with a spending rate of about 6.37% and 6.88% in both rural and urban areas, respectively for the year 2017/2018. It also showed that the annual per capita spending on both meat and fish varies according to the spending categories of the family, and the annual per capita spending on meat in urban areas has increased by 13.65%, 39.64% from its counterpart in rural in each of the second spending category (50 thousand - less than 100 thousand pounds) and the third category (100 thousand pounds or more), respectively, and an increase in the annual per capita spending on fish in urban areas by 6.1%, 23.29% and 84.17% over its counter-part in the rural in the three spending categories, respectively. The spending flexibility in urban areas compared to the countryside on the two groups of meat and fish also increased, as the spending elasticity of the meat group reached about 0.492 and 0.677 in both rural and urban areas, respectively, while the spending elasticity for fish reached about 0.369 and 0.645 in both rural and urban areas, respectively.
اظهر المزيد [+] اقل [-]Natural Pigments Production by Local Bacterial Isolates for Use as Antibacterial and Antioxidant
2021
Sohila El-Sayed | El-Sayed Saleh | Khadiga Aboutaleb
Among 46 local bacterial isolates capable synthetized pigments, 26% produced extracellular of blue green and fluorescent whereas 74% produced intra-cellular pigments of red, brown, yellow, orange, and rose. Seven isolates were selected as a potential candidate for the synthesis of pigments. They were Pseudomonas fluoresces, P. aeruginosa, Serratia marcescens, Azotobacter chroococcum, Micrococcus kristinae, M. luteus, and M. roseus after their morphological and biochemical studies. They capable to produce fluorescent, blue green, red, brown, orange, yellow, and rose with maximum absorbance at 400, 520, 530, 320, 440, 460, and 470 nm, with an optical density of 0.62, 1.42,1.35, 1.11, 0.45, 0.98, and 0.40, respectively. Antibacterial activity of pigments was studied against 7 bacterial pathogenic strains namely P. aeruginosa ATCC27853, Escherichia coli 0157h7 ATCC25922, Klebsiella pneumonia ATCC00607, Salmonella typhimurium ATCC25566, Listeria monocytogenes ATCC19115, Staphylococcus aureus ATCC29737, and Bacillus cereus ATCC33018. The last tested strain behaved high significant (p≤ 0.05) sensitivity for blue green, fluorescent, brown, and rose pigments while, L. monocytogenes ATCC19115 was more susceptible for red, and yellow pigments and S. aureus ATCC29737 had more inhibited by orange pigment. These bacterial pigments seemed to have antioxidant activity which inhibited the formation of diphenyl-2-picrylhydrazyl radicals with percentage ranged from 40 % to 80 %. It could therefore be stated that the bacterial pigments tested had a broad impact on foodborne pathogens and had an antioxidant effect
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