خيارات البحث
النتائج 771 - 780 من 1,443
EFFECT OF PHOSPHATE ROCK AND TRIPLESUPERPHOS-PHATE ON GROWTH AND LEAF N, P AND K CONTENTS OF GROUNDNUT (ARACHIS HYPOGAEA L.) GROWN ON A CLAY SOIL
2006
Elsheikh M.A. | A.M.A. El-Tilib | E.A.E. Elsheikh | A.H. Awad 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 cur-rently imported triplesuperphosphate (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 seasons. 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 significantly (P>0.05) in-creased dry weights of shoot and root, leaf contents of N , P and available soil phos-phorus. However, plant height was significantly 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. Moreover, the results revealed that the plant measurements obtained from PR treatments were comparable to those obtained from TSP treatments which indicate that PR can be used as a potential source of phosphorus fertilizer.
اظهر المزيد [+] اقل [-]NATURAL OCCURRENCE OF CITRININ AND BIOCONTROL OF ITS PRODUCING FUNGUS BY Trichoderma hamatum IN RICE GRAINS
2006
Ezzat S.M. | E.F. Abd-Allah
Paddy rice was sampled from El-Sharkia, El-Gharbia, El-Dakahlia and Kafr El-Sheikh governorates, Egypt. Of the 29 samples taken, ten were contaminated with the mycotoxin citrinin. An average of 6.79 x 104 fungal spores per gram rice was found. The isolated fungi represented 47 species belong to 28 genera. The predomi-nant genera were Aspergillus, Cladosporium and Penicillium. Aspergilli were represented by 22 species; Aspergillus niger and A. flavus had the highest occur-rence. Penicillium viridicatum produced the highest amount of citrinin on glucose ammonium nitrate salts broth and rice grains and hence, this isolate was selected as a good producer of citrinin in this study. The presence of Trichoderma hamatum re-duced the amount of citrinin produced by P. viridicatum compared with its respec-tive control. The excessive growth of T. hamatum on P. viridicatum was increased with time. Viability of P. viridicatum conidia decreased by T. hamatum with an in-crease in the incubation period. Chitinases and 1,3-B-glucanase enzyme activity of T. hamatum increased with extending the incubation period on P. viridicatum cell walls up to maximum values at 72 and 84 h, respectively. T. hamatum led to a de-crease in the production of citrinin by P. viridicatum on rice grains compared with the respective control values.
اظهر المزيد [+] اقل [-]IN VITRO PROPAGATION OF SOMATIC EMBRYOGENESIS-DERIVED PLANTLETS OF CITRUS
2006
El-Sawy, A. A. | A. Reda | A. Gomaa | Nansy Danial
Nodal stem segments of in vitro growing somatic embyogenesis and seedling-derived plantlets of sweet orange, C. sinensis (L.) of (Washington navel, shamouti and blood orange cvs.); grapefruit, C. paradisi (L.); Local mandarin, C. deliciosa (Tenor); lemon, C. limon; (L.); citron, C. medica (L.); lime, C. aurantifolia (Christm); rough lemon, C. jambhiri (Lush) and sour orange, C. aurantium (L.) were cultured on MS medium supplemented with different concentrations of BA (0.5,1.0 and 2.0 mg/L) alone or in combination with NAA (0.5 mg/L) for shoot multiplica-tion. The results indicated that somatic embryogenesis-derived plantlets can be suc-cessfully propagated in vitro with a good vigor compared with germinated seedlings. A large number of proliferated shoots were produced when these explants were cul-tured on MS medium containing 0.5mg/L of BA combined with 0.5mg/L of NAA. Most obtained shoots were rooted on half-strength MS medium containing 0.5 mg/L of NAA. These in vitro grown plantlets were then successfully transferred to green house through acclimatization process.
اظهر المزيد [+] اقل [-]EFFECT OF FORWARD SPEED OF POTATO HARVESTER ON TUBERS DAMAGE
2006
Al-Hamed S. A.
The effect of the forward speed of a potato harvester on tubers damage was in-vestigated. The potato harvester type is a two-row potato digger with riddle chain. The experiments were conducted in a potato field of Haradh Project of the National Agricultural Development Company (NADEC) east of Riyadh, in a sandy loam soil, and for a potato crop planted during the spring season of 2004. The potato type was Hermes (oval graded tubers). The degging depth was set to 22 cm, and the ampli-tudes of riddle chain of the implement were 17 and 25 mm. Results showed that the average values of tubers lifting percentage were in close agreement for all forward speed values (1.5, 1.7, and 2 km/h) of the potato harvester. However, it ranged be-tween 96% and 99%. It was found that there is no significant effect of the forward speed on both total damaged tubers percentage and damage index. However, there was a significant difference for the damaged tubers percentage when the amplitude of riddle chain was changed from 17 to 25 mm, where it decreased as the amplitude was increased. The values of potato damage index for all forward speeds were with-in acceptable limits of damage index. Minimum value of damage index was 0.04 at the speed of 2 km/h and amplitude of 25 mm.
اظهر المزيد [+] اقل [-]MOLLUSCICIDAL EFFICACY AND TOXICITY OF SOME PESTICIDES UNDER LABORATORY AND FIELD CONDITIONS
2006
Abdel-Halim K.Y. | A.A. Hussein | R.K. Abou-El Khear
Laboratory and field trials were carried out at Koom Hamada district and Etay El-baroud research station during 2004/ 2005 season to clarify the molluscicidal ac-tivities of the following: indoxacarb, lufenuron, Bacillus thurringiensis, kurestaci (Bt.) and methomyl against glassy clover snails Monacha cartusiana (Müler). Re-sults indicated that all tested pesticides decreased snails population compared with control. Under the field conditions, the efficiency of the tested compounds were 98.0, 93.4, 93 and 71.58% for methomyl, lufenuron, indoxacarb and Bt. after 5, 6, 13, and 28 days of treatment, respectively. Moreover the effect of LC50 and 0.5 LC50 of these compounds were investigated on some biochemical parameters in vivo. The activities of acetylcholinestrase (AChE), alanine aminotransferases (ALT) , as-partate aminotransferases (AST) and protein contents at different time intervals were evaluated. The specific activity of AChE reached 0.009, 0.002, 0.006 and 0.001 mole/ mg protein/ min for indoxacarb, lufenuron, Bt. and methomyl, respectively, after one day of treatment with (LC50 for each compound). In general, Bt. and in-doxacarb caused slight inhibition on AChE enzyme. All treatments decreased ALT and AST enzyme activity in the tested animals. However, Bt. Showed slight effect on the activity of aminotransferases enzymes.
اظهر المزيد [+] اقل [-]EVALUATION OF ORGANIC AND CHEMICAL FERTILIZERS EFFECT ON RHIZOSPHERE MICROFLORA AND POTATOES (SOLANUM TUBEROSUM.L) YIELD IN LOAMY SAND SOIL
2006
Abo-Sedera S.A.
A field experiment was carried out in a newly cultivated soil at Falouga, El-Tahrir province, Behira governorate during the summer season (Spring plantation)of 2003 to investigate the effect of different organic manures (i.e. compost, F Y Mor town refuse) each at rate of 20 ton/fed combined with the half recommended doseof mineral fertilizer (NPK) or 2 tons of chicken manure compared with the additionof the recommended dose of N P K at rate of 900, 400 and 200 Kg/fed ammoniumsulphate, calcium superphosphate and potassium sulphate respectively. Applicationof organic manures, i.e. compost, FYM or town refuse each at the rate of 20tons/fed combined with half amount of mineral fertilizer or 2 tons of chickenmanure, increased total microbial count in soil at 60 days after planting compared toboth uncultivated soil and chemical fertilized treatments. In this regard, the highestbacterial count was noticed in case of using FYM + chicken manure, while thehighest count for total fungi and actinomycetes were recorded in the treatment of 20tons compost + half amount of chemical fertilizer (NPK). In addition, using 20 toncompost + 2 tons of chicken manures/fed, reflected the highest dry matter yield,total nitrogen, phosphorus and potassium content in plant foliage as well as totaltuber yield of potatoes compared with other tested treatments.
اظهر المزيد [+] اقل [-]SURVIVABILITY OF ESCHERICHIA COLI 0157:H7 AND NON- 0157 SEROTYPES ISOLATED FROM SOME DAIRY PRODUCTS UNDER STRESS CONDITIONS
2006
Zeinab I. Sadek
Microbiological assay of 150 samples of dairy products for the incidence of Co-liforms, E. coli, E. coli 0157:H7 and non-0157 E.coli, show the recovery of the Coli-forms and E.coli from the tested products with different incidence percentage. Strains of E. coli 0157:H7 and non-0157 E .coli were recovered from 9 (6%) and 13(8.6%) of the total samples, respectively. The behaviour of these isolates were tested when exposing to low pH, salt, low holding temperature and heat treatment. The results indicate obvious survival of E. coli 0157:H7 and non-0157serotype with pH as low as 3.8 pH for 5 days. Also, survival or even multiplication in TSB con-taining <6% salt. Moreover, the strains remained viable at low holding temperature (5oC). So, the product which contaminated with this pathogens remain hazardous even under such stress condition. Decimal reduction times (D-values) of cells sus-pended in saline solution, TSB medium, reconctituted dry milk and chocolate milk were determined. The greatest survival as evidenced by highest D and Z values oc-curred with chocolate milk. Product composition and type of strain affected the heat lethality rates.
اظهر المزيد [+] اقل [-]GROWTH, YIELD AND YIELD COMPONENT OF INOCULATED CHICKPEA AND FABA BEAN PLANTS AS AFFECTED BY USING METHYLOTROPHIC BACTERIA
2006
Sawsan Shehata | Wedad E.E. Eweda | H.H Abo Taleb | Heba O.M. Orf
Two pot experiments were performed in Giza research station, AgriculturalResearch Center (ARC) using 2 isolates of Pink-Pigmented FacultativelyMethylotrophic bacteria (PPFMs) originated from chickpea and Faba bean. Foliarapplication with PPFM isolates were conjugated with specific rhizobial inoculumand N-fertilization (15 Kg N Fed-1). Nodulation status, nitrogen fixation and growthyield and yield component were recorded. Results clearly indicated that Chickpeawas superior in its response to foliar application with PPFM.C. As it gave higherrecords of number and dry weight of nodules, dry matter and N-content of plants ascompared to Faba bean. A field experiment was also conducted in sandy loam soil atSouth EL-Tahreer province to investigate the effect of foliar application withPPFM.C strain + specific Rhizobia and N-fertilization on nodulation, growth andyield of chickpea legume plants. Results indicated that foliar application withPPFM.C in the presence of specific rhizobial inoculation scored significant increasesin economic turnover of chickpea in the range of 21-32% as compared to Nfertilizationat rate 50 Kg N Fed-1. Foliar application with 5 L Fed-1 in the presenceof 15 Kg N Fed-1 and specific rhizobial inoculation led to an increase of 518 kg fed -1productivity of seed yield , with economic turnover of 2491 L.E.
اظهر المزيد [+] اقل [-]PRODUCTION OF PROBIOTIC LOW-CALORIE SOUR CREAM
2006
Fayed A.E. | Gehan A.M. Hussein | Azza M. Farahat
The production of probiotic low calorie sour cream was aimed to experiment in relation to its compositional, bacteriological, biochemical, rheological and organo-leptic properties along the cold storage period of the product. Cream based on 36% total solids (TS) and 30 % fat was made using the obtained fresh cream (54 % TS and 50 % fat) and liquid skimmed milk (9 % TS).To produce low-calorie sour cream, fat content was lowered to 20 and 10 % depending on the addition of Sim-plesse100® to mimic milk fat on the basic of 0.1% fat mimetic is instead of 1.0% fat. Dried whey protein concentrate (DWPC, 95 % TS) was used as bulking agent to overcome the loss occurred in the TS content due to the reduction in the fat content. Thereafter, all creams were homogenized at 55-60°C and further heat treated to 74°C for 30 sec. followed by rapidly cooling to the appropriate temperatures. Then creams were inoculated with 2% freshly prepared bacterial starter culture and incu-bated at 30 or 37 °C, to reach pH value about 4.6, for cream cultured with R-704 or ABT-2 type starter culture, respectively. The results indicated that, the proportional fat replacement of cream led to gradual increase in the protein, carbohydrate and ash contents, and decreased the caloric value. There are a backward relationship between the bacterial population and the fat content of the sour cream. Where, in the product cultured with ABT-2 type, Lactobacillus acidophilus grew and predominated in all other accompanying strains overlooking either the fat content or the cold storage pe-riod (CSP). Streptococcus thermophilus populated the 2nd predominance order fol-lowed by Bifidobacterium sp., which tended to proximate and preceded, actually, Str. thermophilus by prolonging the CSP of the lowest fat-content cream (10%). The increase rate of the bacterial count continued until 3rd weak for Lb. acidophilus and to 1st weak for Bifidobacterium sp.. Thereafter, gradual decreases were occurred. However, Str. thermophilus began to decrease from the 1st day of CSP. Although the count of bacterial type R-704 was always higher, it behaved a trend similar to that of Bifidobacterium sp. toward the CSP. Sour cream of ABT-2 type contained higher ti-tratable acidity (TA) % as well as lower pH, acetaldehyde (AC) and diacetyl (DA) values than that cultured with R-704 type. Along CSP of sour cream the increment in AC, DA and TA contents continued, in order, until the 7th , 14th and the end of theFayed; Gehan Hussein and Azza FarahatArab Univ. J. Agric. Sci., 14(2), 2006experimental period. As the protein content raised at the expanse of the fat content via adding DWPC, which was in the denatured form, the firmness, consistency coef-ficient, and yield stress of sour cream increased, especially when ABT-2 type was used and the CSP progressed. Furthermore, ABT-2 sour cream was sensory distin-guished with, nearly, similar appearance as will as better flavour and consistency ra-ther than that of R-704. The fat reduction to 20 % did not influence the overall sen-sory quality, while that of 10% fat attained panel score averaged 93.5 % of the con-trol when ABT-2 type was used. As a conclusion, it is successfully possible to pro-duce probiotic low calorie sour cream with excellent sensory attributes using Sim-plesse100® as fat mimetic and bacterial type ABT-2 as starter culture.
اظهر المزيد [+] اقل [-]ACTIVITY OF PEACH TWIG BORER Anarsia lineatella Zeller AND ITS ASSOCIATED BIO AGENTS ON PEACH TREES
2006
Salwa S.M. Abdel-Samad
The seasonal activity of the peach twig borer, Anarsia lineatella Zeller was in-vestigated during 2004 and 2005 seasons. The data revealed that the infested twigs empty from larvae (15%) were higher than that with larvae (1.25%) in February. The situation was reverse in April which recorded 8% and 14.75% for both, respec-tively. In fruits, infestation began to appear in the third week of March which rec-orded 2% whereas the maximum rate was recorded in May (16.75%). Three species of hymenopterous parasitoids were found; Apanteles ruficrus Haliday (Fam. Braco-nidae), Diplazon laetatorus Fab. (Fam. Ichneumonidae) and Microgaster tiro Rein-hard (Fam. Braconidae). These parasitoids reached its maximum during April (13.5%) that seems to be more active. Their numbers were positively correlated with the rate of infestation (r = + 0.799). In spite of presence of four predatory species (Coccinella undecimpunctata L., Rodalia cardinalis Mulsant, and Scymnus syriacus Marseul (Coleoptera: Coccinellidae) and Syrphus sp. (Diptera: Syrphidae)), it seems to be less active. Their numbers recorded very slight positive correlation with the rate of infestation (r =+0.423)
اظهر المزيد [+] اقل [-]