خيارات البحث
النتائج 21 - 30 من 64
Potential the biological or chemical control of lettuce white rot and maintain productivity
2020
Samuel Allah | Ahmed Abou El-Yazeid | hany gamal | ahmed bondok
The experiments were executed on the autumn and the winter of (2016 /2017, 2017/2018) seasons at Qalyub area, EL-Qalyubia governorate, Egypt. The main objective for this study to find out the efficacy of several biological and the chemical controls on growth and productivity of lettuce crop and management on white rot disease caused on Sclerotinia sclerotiorum. Thus, four treatments were applied as follow 1- the control (water application),2- Trichoderma asperellum, 3-Salicylic acid and 4- Calcium Chloride, which were evaluated and compared for the three fungicide as follow : 1- Iprodione , 2- Tebuconazole with Fluopyram and 3-Tebuconazole at the doses (85 & 100 ; 200 &100 and 50 &100 g or ml / 100L-1 respect.) . Which they tested for their ability for increasing the lettuce crop productivity and suppress mycelial growth of S. sclerotiorum pathogen by treatments were sprayed on two times on plants at (15-19 BBCH) stages by using backpack sprayer by 250 L./Fed.). Results indicated that, Iprodione applications significantly gave the highest indications of total and the Marketable yield in compared with the other experimental treatments for both seasons. Moreover, the two times of sprayes by Iprodione and Salicylic acid treatments had significantly lowered the disease incidence and disease severity and increasing the control efficiency in the both seasons. Whereas, the other treatments, Tebuconazole with Fluopyram or Tebuconazole and Trichoderma asperellum had a moderate effecacy on the lettuce crop productivety or the disease severity and incidence of Sclerotinia sclerotiorum in compared to the control treatment. In the contrast, application by Calcium Chloride had a low effect on the average yield or final yield as a mass and marketable plant in the both seasons and had insignificant effect on the disease severity or incidence of S. sclerotiorum despite low to medium recovery following applications. Finally, the control treatment was the lowest.
اظهر المزيد [+] اقل [-]IMPACT OF HEAT STRESS ON GROWTH PERFORMANCE AND CARCASS TRAITS IN SOME BROILER CHICKENS
2020
Omer Omran‏ | Ahmed Galal | Mahmoud Mahrous | Faisal Bayoumi
Environmental heat stress is one of the most challenging conditions in the world which have adverse impact on the industry of poultry. Broiler chicken strains are delicate to heat stress primarily due to not having sweat glands. The current study was aimed to investigate the effects of heat stress exposed on growth performance and Bio-physiological characteristics for (Cobb, Hubbard and Arbor Acres broiler hybrids) under the summer season when environmental conditions of Egypt were revealed. A total of three hundred one day old (one hundred birds from each hybrid) at one day of age were brooding under the same conditions of water, diet consumed, breeding system, vaccines and medications used during the period birds life even slaughtering age. The three strains were randomly divided into twelve groups (three strains "Cobb, Hubbard and Arbor Acres" X two treatments "control group and heat exposed group" X two replicates X twenty five chicks).The degrees of environmental temperature and relative humidity during housing are (Environmental temperature = 32°±2 Celsius degree, Relative humidity =50±5 percentage) for control group and (Environmental temperature =40°±2 Celsius degree, Relative humidity= 20±5 percentage) for the heat stressed group. The body weight, body weight gain, edible parts of carcass (carcass, thigh, drum, breast muscles and giblets weight) and inedible parts of carcass (blood, feathers, head and legs weight) were recorded to heat stressed group and control group. Lymphatic organs such as spleen, thymus and bursa weight were measured also. The last results concluded that the Cobb strain showed the best growth performance and carcass characteristics under heat stress condition, while the Arbor Acres strain considered the best strain which didn't effected a lot in their rectal temperature such another strains with heat exposure. The Arbor Acres strain for each group (control and treated) have the highest viability. The control group and Hubbard strain showed an increase in bursa weight compared to heat exposed group and another strains. It was concluded that the Cobb strain has the best performance under heat stress comparing to the other strains broiler chicken.
اظهر المزيد [+] اقل [-]Assessment of Spectroscopic and Morphological Properties of some Fruit Crops under the Influence of Pollution with Heavy Metals Using Remote Sensing Techniques
2020
Amany Abd Elhameed Elwesemy | Nazmy Abd Elghany | Ayman Abouhadid | Mohamed Aboelghar
Dietary exposure to a variety of heavy metals, including Ni, Cd, Cr, Pb, Zn, and Hg, has been identified as a danger to human health through fruits and vegetables, contamination of heavy metals is known as a grave risk to our climate. The study aims to develop empirical models to predict the concentration of heavy metals (Ni, Cd, Cr, Pb, Zn, and Hg) in the leaves of Citrus and Mango crops. The study was carried out in an observation site in Giza governorate that is cultivated by varied herbaceous and tree cover crops. This study area is suffering from severe pollution caused by near industrial district. The sample collected from deferent zones that are divided to six spatial zones and coded by from zone (2, 3, 4, 5, and 6). The distance between each Zone 10 Km that extends from the north to south and covers 60% from the Agriculture area in the Giza governorate. The main inputs of the generated models were spectroscopic remotely sensed data and laboratory analytical measurements of heavy metals in crop leaves. ASD (Analytical Spectral Devices) field spectro-radiometer was used to calculate hyper-spectral vegetation indices. Modeled heavy metal concentrations were tested against laboratory analysis through two common statistical tests; the Correlation of determination (R2) and Root Mean square (RMSE) error between predicted modeled heavy metals. Results shown the correlation coefficient of the generated models, red and near-infrared spectral bands demonstrated high precision and sufficiency for mango and citrus leaves to predict heavy metals. The models produced refer to specific regions with the same conditions. The overall results imply that hyper-spectral vegetation indices could be correlated with heavy metal content, while heavy metal content in plants may be influenced by many others. Remote sensing spectroscopy is a possible and promising technology to track the environmental pressures on agricultural vegetation. Additional ground remote sensing experiments are needed to assess the possibility of hyper-spectral reflectance spectroscopy in monitoring the stress of different types of metals on various plants.
اظهر المزيد [+] اقل [-]Quantifying the hydraulic properties of some Egyptian soils using RETC code
2020
Ahmed Talat | Mohamed Galal | Arfa yeser | A. A. Saad El-Dein
Temporal and spatial soil variabilities reduce the accuracy of quantifying the hydraulic properties of the soil, leading to poor irrigation management. Modeling estimation and computer codes (e.g., RETC code) have been used to quantify and predict soil hydraulic properties. One hundred soil samples were collected to represent soil textural classes according to USDA textural triangle. Following the physical, chemical and hydraulic characterization of the soil samples collected, one soil sample was chosen to represent each texture class. The selected soil samples covered six USDA textural classes. Then, Brooks-Corey (B-C) (1964) and van Genuchten (vG) (1980) parametric models were used to describe the functional relationship between soil water tension and water content, i.e. the soil water retention curve, and the Mualem (1976) theoretical models of pore size distribution were used to predict the functions of unsaturated conductivity K (θ) and soil water diffusivity D (θ). The RETC (retention curve) code was used to obtain the parameters of vG and B-C models by simultaneously matching to the observed data. Output file of refining process showed the iteration levels to achieve minimum value of residual summed square (RSSQ).The values of determination coefficient (R2) of the fitted θ (h) as a power function increased after fitting the experimental data either in B-C or in vG models. The values of R2 of the fitted equation of θ (h) with both B-C and vG data increased after refining process through RETC code. The increments of R2 values after refining are more pronounced in coarse textured samples (Sand, Loamy sand, and Sandy loam).The values of determination coefficient (R2) of the fitted functions K (θ) and D (θ) as a power function are highly significant after fitting soil parameters either in B-C or in vG models. While using RETC code refined the obtained soil parameters of both K (θ) and D(θ) increasing R2 values of fitted power function and reducing residual summation square. RETC reduced the value of residual summed square (RSSQ) of the objective function O(b) under using both B-C and vG models. This reduction of RSSQ by using RETC fluctuated between 60.4% and 98.2% with B-C for six soil textural classes. While, the reduction of RSSQ by using RETC fluctuated between 90.4% and 98.6% with vG for the same six soil textural classes. In general, the RETC code is a good tool for obtaining accurate values of hydraulic properties in a variety of soil textures.
اظهر المزيد [+] اقل [-]MONITORING OF COUNTERFEIT ABAMECTIN PESTICIDE PRODUCTS IN EGYPT.
2020
Gehad Khattab | Walaa Abdelghany | Mohamed Abdelmegeed | Ibrahim Attalah
The monitoring of the counterfeit situation of a pesticide widely used in Egypt (abamectin) was done through the present study as seven samples of Abamectin formulations were collected from the Egyptian market. Packaging and labels were checked and analyzed by HPLC to determine the active ingredient content present in these samples. GC-MS and FTIR were used for additional analysis and detection of other active ingredients in the formulation.Counterfeit pesticides were studied in Egypt by doing questionnaires for all workers in the pesticide system (farmer - trader - researchers in the pesticide field) and the results of these forms were analyzed to show the most dominant pesticides in Egypt, in addition to random purchase of pesticides from the Egyptian market and the most number of samples Is from (abamectin pesticide) (7 samples).To obtain this number of abamectin formulations, 58 different pesticide formulations (16 different active ingredients) were collected from the Egyptian markets, and the share of abamectin was 7 samples (one active substance), representing 12.1% of the total tested samples. The obtained results showed that Examination of Packaging and indicated that three samples were not registered through Egyptian Agricultural Pesticides Committee thus representing 42.86% of the total tested samples. The non-registered products are Komaktin Gold Plus, Super Vertimic and Abamectine Strela. Three samples have registration number as other formulations already registered in Ministry of Agriculture which are Abamectin Super, Farmactine and Abamectin power. The last product (Tinam) has the correct registration number (no.1391) and it is the same number used to register it in Ministry of agriculture. The percentage of the active ingredient in 5 samples was less than the acceptable limits, The samples were (Abamectin super, Komaktin Gold Plus, Abamectin Power, Super vertimic and Abamectine strela) active ingredient content was 1.416, 0.64, 1.01, 0.2 and 0.12% respectively. One sample (Farmactine) didn’t contain Abamectin, and the sample (Tinam) was within the acceptable limits (1.53%). GC-MS used to determine the presence of any other materials or active ingredients within the samples. The result showed that Abamectin Super sample contains (Lambda cyhalothrin at R.t. 29.512 min), Farmactine sample contains (Fenpropathrin at R.t. 28.634 min), Abamectin Power sample contains (Diazinon at R.t. 16.088 min and Cypermethrin at R.t. 26.554 min) and Super Vertimic sample contains (Fenpropathrin at R.t. 23.916 min and Lambda cyhalothrin at R.t. 34.85 min). Three products Komaktin Gold Plus, Tinam and Abamectine Strela didn’t contain other active ingredients.The physical properties of the studied samples before and after storage were determined through emulsion characteristic test and four samples (Abamectin super, Farmactine, Abamectin Power and Tinam) showed good emulsion characteristics before and after storage. Super vertimic and Abamectine strela samples showed poor emulsification characteristics before and after storage. Komaktin Gold Plus showed good emulsification before storage but poor emulsion characteristics after storage.
اظهر المزيد [+] اقل [-]HISTOLOGICAL CHANGES ACCOMPANYING ADVENTITOUS SHOOTS FROMATION OF FRAGRAIA X ANANASSA IN VITRO LEAVES
2020
Seham Abed
A tissue culture experiment was conducted to attain the adventitious buds initiation and growth from Fragraia x ananassa cv. Festival in vitro leaves. The leaves were excited from shoot propagated in vitro and cultured on Murashige and Skoog (MS) medium supplemented with 4.50, 6.75, and 9.00 mmol l-1 thidiazuron (TDZ) for six weeks. Then explants were transferred to MS medium (salts and vitamins) free plant growth regulators for 8 weeks. This study included the histological and morphological responses of strawberry leaves with TDZ treatments in relation to some biochemical components. All TDZ treatments resulted in adventitious shoots development on leaf explants without callus formation. Growth in 6.75 mmol l-1 TDZ led to an increment in the most morphological parameters compared to the rest treatments. The results showed that 6.75 mmol l-1 of TDZ treatment significantly increases the number of shootlets per explant (5.0), total shoot (51.3), the number of leaves/explant (12) as compared with other treatments while the rest of parameters (the survival percentage, shoot length (cm), number of leaves/explant, root length (cm), and number of roots/explant) did not show any significant differences. Accumulation of chlorophylls, total sugars, and total soluble phenols was enhanced by 6.75 mmol l-1 of TDZ. The histological observations showed that adventitious shoots initiated from some parenchyma of ground tissue in the midvein zone of the explant, whereas the parenchyma mesophyll and the epidermal cells did not involve in this process. The ontogenesis of adventitious shoots was described by successive stages with the following distinguishable anatomical structures: meristemoids, bud primordium, shoot apex with leaf primordial, branching of adventitious shoots. After four weeks of culture, cell dedifferentiation was recorded in the midvein parenchyma and forming small groups of divided cells called meistemoid centres. These centres forming new meristematic masses embedded in the ground tissue of the main vein. After six weeks, further development of these masses resulted in the formation of bud primordial with normal organized shoot apical meristems and leaf primordial and arising from the explant as small protrusions. After two weeks from subculture on MS free TDZ, the adventitious shoots continue to elongate with forming new lateral branches and clearly observed on the adaxial side of the explant. This procedure provides a simple and rapid approach to regenerate strawberry plants via direct organogenesis.
اظهر المزيد [+] اقل [-]An Economic Study on Tomatoes Export Competitiveness in Egypt
2020
El-Sayed El-Khishin
Vegetables export in general and tomatoes crop in particular are facing serious challenges in Egypt with regards to declining competitiveness in global markets in addition to some other challenges related to the ability to penetrate global markets and the variation in prices for different importing countries. This is in addition to the variation in demand conditions in importing markets. Through reviewing the competitiveness indicators for this crop. the paper shows that the quantity and value of tomato exports was highly fluctuating during the period under investigation. The lowest value was recorded in 2000 and amounted to 1.7 thousand tons. The maximum value was recorded in 2013 and amounted 74.8 thousand tons. Since then. the variable showed high fluctuation until 2018 where the quantity exported reached 41.8 thousand tons. The exporting value also was fluctuating. It reached its lowest in 2000 and amounted to 454 thousand dollars while the maximum reached around 728.7 thousand in 2015. The value decreased to 488.6 thousand in 2018 while the tomato exports also fluctuated since 2000 till 2007 and reached its maximum in 2017 with around $1513 /tons. The value showed a fluctuating trend where it reached around $1169/ton. The Saudi market dominated the market with around 37.16% of total Egyptian tomatoes exports. whether fresh or frozen. The paper also shows that the export competitiveness index for tomatoes during the mentioned period is above unity which means there is clear export competitiveness in global markets. The average index value reached around 1.33. which means that this crop is one of the very important crops that efficiently competes in the global markets.The paper finally shows the penetration parameter is weak and that there is minimal increase in this indicator. This means that there is a possibility to increase exported quantities from tomatoes through studying the reasons behind the fluctuations and design some policies and export mechanisms that can improve export competitiveness and penetration rates.
اظهر المزيد [+] اقل [-]سد النهضة الإثیوبی والزراعة المصریة
2020
Jehad Awdah | Mohamed el-eraky | atef goda
الملخص تعتبر میاه النیل هی أکبر مصادر المیاه فی مصر حیث تمثل حوالی 72.62% من إجمالی الموارد المائیة المتاحة فی مصر، وأغلب الاحتیاجات المائیة فی مصر تعود لقطاع الزراعة حیث تمثل نسبة الزراعة نحو 81.45% من إجمالی الاحتیاجات المائیة فی مصر، وتلیها فی المرتبة الثانیة میاه الشرب حیث تبلغ نسبتها نحو 12.13% من إجمالی الاحتیاجات المائیة فی مصر. کما أنه منذ عام 1947 وحتى عام 1960 کان هناک وفرة نسبیة فی المیاه حیث تراوح نصیب الفرد سنویاً من المیاه بین (2604 -1893) متر مکعب؛ بینما وصلت مصر للکفایة المائیة منذ عام 1970 وحتى عام 1986 وتراوح نصیب الفرد من المیاه من (1672 إلى 1138) متر مکعب. ووصلت مصر للندرة المائیة منذ عام 1996 وحتى الآن حیث انخفض نصیب الفرد إلى نحو 860 متر مکعب. ومن المتوقع أن یصل نصیب الفرد إلى نحو 582 لتر فی عام 2025. ومن المعروف أن حد الفقر المائی هو 1000 م3، أی أن مصر وصلت لحد الفقر المائی بدایةً من 1996 وحتى الآن. ومن المتوقع أن تتسع الأزمة المائیة فی مصر فی عام 2050 حیث یصل نصیب الفرد فی مصر من المیاه إلى 294 م3، ویهتم هذا البحث بدراسة العلاقة المتشابکة بین مصر وإثیوبیا (فی ملف میاه النیل) فی إطار نظریة المباریات، حیث تم استخدام نماذج بسیطة لتحلیل الصراع المستمر والمخاوف بشأن سد النهضة الإثیوبی، ویشیر التحلیل إلى وجود درجة عالیة من الإجهاد المائی وقد یؤدی إلى صِدام مباشر بین دول حوض النیل على الرغم من أن التوصل إلى حل سلمی للمشکلة من الممکن أن یؤدی إلى زیادة العوائد المائیة لکلا البلدین. وبدراسة السیناریوهات المختلفة لملء خزان سد النهضة تبین أن مصر من الممکن أن تفقد حوالی 88% و 66% من أراضیها الزراعیة على الترتیب وفقاً للسیناریوهات الأول والثانی حیث سیتم ملء الخزان فی السیناریو الأول على مدار ثلاث سنوات مما سیترتب علیه نسبة عجزتقدر بحوالی 26% من إجمالی الموازنة المائیة المصریة السنویة مما سیؤدی إلى خسارة 2.6 ملیون فدان سنویاً، أی أنه على مدار 3 سنوات ستفقد مصر حوالی 8 ملیون فدان من رقعتها الزراعیة والبالغة نحو 9.1 ملیون فدان. أما بالنسبة للسیناریو الثانی فسیتم ملء الخزان وفقاً لهذا السیناریو على مدار خمس سنوات مما سیترتب علیه نسبة عجز تُقدر بحوالی 12% من إجمالی الموازنة المائیة المصریة السنویة. وهذا یعنی خسارة سنویة تقدر بحوالی 1.2 ملیون فدان من الأراضی الزراعیة فی مصر، أی أنه بعد مرور خمس سنوات ستفقد مصر حوالی 6 ملیون فدان من جملة أراضیها الزراعیة. ویعد السیناریوهان الأول والثانی هما المرشحان بقوة من قبل الحکومة الإثیوبیة. وأوصى البحث بما یلی: ضرورة التوصل لاتفاق بین مصر وإثیوبیا من شأنه زیادة سنوات الملء لتحمل إثیوبیا جزء من عبء الآثار السلبیة الناجمة عن إنشاء هذا السد الضخم. بالإضافة إلى الإدارة المشترکة للسد تأکیداً لمبدأ حسن النیة کما نصت علیه اتفاقیة إعلان المبادئ التی تم توقیعها بین مصر وإثیوبیا والسودان عام 2015. ومن الممکن أن تصل الثلاث دول إلى استراتیجیة مربحة للجانبین تفید جمیع الدول مع أدنى حد من الضرر الذی قد یلحق بأی طرف. ویمکن لمصر أن تساعد إثیوبیا فی تأمین الکهرباء المطلوبة من موارد أخرى إذا واصلت إثیوبیا الإعتراف بحق مصر فی التمتع بحصتها التاریخیة البالغة 55.5 ملیار متر مکعب فی السنة.
اظهر المزيد [+] اقل [-]تقییم السیاسات الزراعیة لآهم محاصیل الحبوب بإستخدام مصفوفة تحلیل السیاسات
2020
Hala Mohamed Rashad | mahmoudom Odamy | Mosaad Ragab | Abdullah Abdel Maqsoud
- تبین من نتائج قیاس تحلیل مصفوفة السیاسات الزراعیة لمحصولی الدراسة أن معامل الحمایة الأسمی لمستلزمات الإنتاج قد بلغ حوإلی 0.915، 0.915 لکل من القمح والأرز خلال الفترة 2013- 2017، الأمر الذی یشیر إلی عدم وجود دعم لمستلزمات الإنتاج. - کما تبین أن معامل الحمایة الإسمی للنواتج من محصولی القمح والأرز علی الترتیب خلال فترة الدراسة قد بلغ حوإلی 0.771، 0.746، الأمر الذی یوضح إلی عدم وجود سیاسة إنتاجیة عادلة وذلک لقیام الدولة بفرض ضرائب مباشرة وغیر مباشرة علی المنتج وتقدیم دعم للمستهلک. - کما تبین من النتائج إلی وجود میزة نسبیة لمحاصیل الدراسة خلال نفس الفترة ، الأمر الذی یعنی إلی ان معامل المیزة النسبیة أقل من الواحد الصحیح. - کما تبین ان بمقارنة التقییم المإلی والتقییم الاقتصادی لکل من أجور الآلات، ثمن التقاوی، ثمن السماد الکیماوی، ثمن المبیدات، نجد أن التقییم المإلی یقل عن التقییم الاقتصادی لهذه البنود مما یدل على أنها مدعومة من جانب الدولة لمزارعی القمح. - کما تبین ان بمقارنة التقییم المإلی والاقتصادی لکل من إیجار الأرض، أجور الحیوانات، ثمن السماد البلدی، والمصاریف العمومیة یتبین أنهما متساویان مما یدل على عدم تدخل الدولة فی أسعار هذه البنود. - کما تبین ان بمقارنة التقییم المإلی والتقییم الاقتصادی لکل من أجور الآلات، ثمن التقاوی، ثمن السماد الکیماوی، ثمن المبیدات، نجد أن التقییم المإلی یقل عن التقییم الاقتصادی لهذه البنود مما یدل على أنها مدعومة من جانب الدولة لمزارعی الأرز. - کما تبین ان بمقارنة التقییم المإلی والاقتصادی لکل من إیجار الأرض، أجور الحیوانات، ثمن السماد البلدی، والمصاریف العمومیة یتبین أنهما متساویان مما یدل على عدم تدخل الدولة فی أسعار هذه البنود. - کما تبین من النتائج إلی أن قیمة معامل الحمایة الفعال لمحصول القمح بلغت حوإلی 0.756 خلال فترة الدراسة، مما یعنی أن محصول القمح لم یتمتع بحمایة حکومیة خلال تلک الفترة. - کما تبین من النتائج أن قیمة معامل الحمایة الفعال لمحصول الارز بلغت حوإلی 0.723 خلال فترة الدراسة، مما یعنی أن محصول الأرز لم یتمتع بحمایة حکومیة خلال تلک الفترة.
اظهر المزيد [+] اقل [-]Assessment and Spatial Analysis of Sensitivity to Desertification in Wadi El Natrun, Northwestern Egypt using MEDLAUS model
2020
Hoda Nour-Eldin | Abdel -Aziz Sheta | Adel Shalaby | Mohammed Abd- El Wahed | Mohamed EL-Shinawy
Land degradation is a global environmental issue, given the various negative impact on socio-economic and ecological implications. It leads to reduced production capacity in addition to soil erosion, physical /chemical /biological /economic land deterioration, and long-term loss (or degradation) of vegetation. When a severe deterioration in drought areas called the process of desertification i.e. arid, dry sub-humid and semi-arid areas. Desertification processes reduces the productivity of the soil and as a result effect on food stocks. The main objective of this study is integrating remote sensing data and a geographic information system (GIS) to evaluate the environmental sensitivity for desertification in Wadi El Natrun, Egypt based on the Mediterranean Desertification and Land Use (MEDALUS) approach. The collected soil data; from description of represented soil profiles and analysis of soil samples, in addition to climate, plant cover, and management data were considered for assessing the sensitivity of desertification. The obtained results showed that 10.4 % of Wadi El Natrun area is considered severe sensitivity to desertification as a result of alkalinity and salinity, while the moderately sensitive area occupies approximately 10.93 % of the study area. The low sensitive one exhibits 76.3 %. This area is described by high soil quality because of the study area is one of the new development areas which were not affected by the factors of desertification. It can be concluded that the desert extension of El-Beheira Governorate (i.e. Wadi El Rayan) is one of the areas that possess valuable land resources which should be considered for future land reclamation projects. Similar international studies are recommended to be achieved with the use of multi-criteria GIS modeling (i.e. MEDALUS) which considered all relevant factors in the form of thematic layers for easier implementation and assessments. Present study represents one of the initial attempts to use the MEDALUS model for desertification assessment in the desert extension of El-Beheira Governorate.
اظهر المزيد [+] اقل [-]