خيارات البحث
النتائج 1 - 10 من 21
THE SEASONAL ABUNDANCE OF SUNN PEST EGG PARASITOIDS Eurygaster integriceps Put. IN THE NORTH EAST OF SYRIA
2018
S. Sheikhmoos | M. Nehal | M. Al-Sltil | Randa Tara
The study of distribution and field efficacy of egg parasitoids was conducted in several wheat fields in north east of Syria (Amoda, Al-Qamishly, Al- Qehtanya, Al-Jwadya and Al-Malikya) in the 2011 field season. The results of surveys and taxonomy showed that fives parasitoid species belonging to Scelionidae family and order of Hymenoptera are: Trissolcus grandis Thomson, Trissolcus simoni Mayr, Trissolcus semistriatus Ness, Trissolcus vassiilievi Mayr and Gryon fasciatus Priener. The abundant species were T. grand which occurred in all sites and rate parasitism reached to 37.74% to all eggs, and T. vassilievi which occurred in all sites except Amoda and parasitism reached to 32.10%. T. semistriatus recovered in Al-Qamishly, Al- Qehtanya and Al-Malikya and parasitism reached to 16.98%. T. simoni was recovered only from Amoda, Gryon faciatus only from Al-Malikya. Overall parasitism rates reached 44.17% throughout the season.
اظهر المزيد [+] اقل [-]ISOLATION, SCREENING AND IDENTIFICATION OF PROMISING YEAST ISOLATES USED FOR BIOLOGICAL CONTROL OF ORANGE GREEN MOULD
2015
Shehata, S. T.
Ninety nine yeast isolates were isolated from surface of apple, grape, orange and tomato fruits. The isolates were tested in vivo in preliminary study for biocontrol potential against green mould of navel orange fruit. According to primary screening, twenty two isolates were selected to continue the secondary screening (phase one) using different concentrations of the washed yeast cells in water suspension to evaluate their biocontrol efficacy at 21±1°C. Among twelve yeast isolates were passed to the secondary screening (phase two) at 7±1°C, washed cells of yeast isolates CT 503, CT 507, CT 508, CT 512 and CT 550 at 1x109, 2x108 and 1x108 CFU/ml produced complete protection for 21 days to wounded navel orange fruits inoculated with spore suspension of Penicillium degitatum (1x104 conidia /ml). Meantime, no lesions developed on the navel orange fruits treated with the yeast isolates CT 503, CT 507 (Debaryomyces hansenii var. hansenii strain C) and CT 512 (Endomycopsella vivi) at 6.6x107CFU/ml, while the percentage of rot reduction of the isolate CT 550 (Candida edax) was 99.81%. Culture filtrate of twenty two different yeast isolates used in secondary screening (phase one) did not prevent decay of wounded navel orange fruits but had an inhibitory effect on rot development. The relative abilities of the promising yeast isolates (CT 503, CT 507, CT 512 and CT 550) to induce disease resistance against P. digitatum on navel orange fruits were studied. Inoculation of promising yeast isolates significantly triggered induction of resistance in navel orange fruits. The lesion diameters of green mould 66 hours later after inoculation by spore suspension of P. digitatum in a neighbouring wound that was made approximately 6 mm away from the initial woundwhich inoculated withthe isolates CT 512, CT 550, CT 507 and CT 503 were reduced by 25.5%, 20.5%, 16.7% and 14.1%, respectively. In this respect, there were no significant differences among the three different isolates CT 503, CT 507 and CT 550.
اظهر المزيد [+] اقل [-]BIOLOGICAL CONTROL OF LASIODIPLODIA ROT OF MANGO FRUITS BY YEASTS
2014
S.T. Shehata
Ninety nine yeast isolates were isolated from surface of mango fruits and were tested in vivo in preliminary study for biocontrol potential of Lasiodiplodia rot of mango fruits. According to primary screening, nine isolates were selected to continue the secondary screening using different concentrations of the washed yeast cells in water suspension to study their biocontrol efficacy at 16±1°C. It was found that using washed cells of yeast isolate Mg 147 (Candida multisgemmis) at 1x109, 5x108 and 2x108 CFU/ml produced complete protection for 14 days to wounds of mango fruit inoculated with spore suspension of the fungusLasiodiplodia theobromae 1x105 conidia/ml. Meantime, no lesion developed on the mango fruit treated with the isolates Mg 39 (Pichia guilliermondii strainA) at the highest tested colony forming unit (CFU) levels, i.e. 1x109 and 5x108 CFU/ml. Supernatant of the yeast cultures, tested in secondary screening, did not prevent spore germination of L. theobromae or decay of wounded mango fruit but had inhibitory effect. However, 1-Methylcyclopropene (1-MCP) treatment significantly reduced the infected area mm2 on mango fruit inoculated with L. theobromae (1x105 conidia/ml) during the 14 days of storage at 16±1°C and improved efficacy of isolates Mg147 and Mg39. When applied as combined treatments between 1-MCP and biocontrol agents, no lesion developed on the fruit treated with the isolate Mg 147 at 1x 108 CFU/ml or higher. Meanwhile, no lesion developed on the fruit treated with the isolate Mg 39 at 2x 108 CFU/ml or higher while, the percentages of rot reduction were ranged between 94.1% - 81.3% for concentrations 1x108 and 6.6x107 CFU/ml respectively.
اظهر المزيد [+] اقل [-]BIOLOGICAL CONTROL OF TICKS IN SMALL SCALE DAIRY FARMS IN THE SUDAN
2008
Hassabo A A
Twenty dairy cows belonged to four small holder were put under study, to investigate the efficiency of using scavenger chicken (baladi) as biological control of ticks and their borne diseases. The cows were divided to two groups first and second, they were infested with ticks, Laboratory diagnosis for babesia was carried out. All samples showed positive reaction.Cloxon 2.5 gm/kg/ body weight (BW) was used to treat the cows of the two groups with the presence of ticks, and all cases were recovered. Gamatox was used to control the ticks on the cows in the first group, while scavenger chicken (5 baladi chicken in each farm), were used to control ticks in the second two farms. After seven days no tick was observed on the cows in the second group. It also showed negative result for babesia test. On the other hand, nymphs were noticed on the cows of the first group. The research recom-mended to use scavenger chicken to terminate the life cycle of ticks and to get rid of its pathogenic diseases in small scale dairy farms.
اظهر المزيد [+] اقل [-]MANAGEMENT OF BROWN ROT DISEASE OF POTATO
2007
S Mahmoud
Different applications [various potato cultivars, chemical fertilizers, bioagents and chemical in-ducers] were used for controlling brown rot dis-ease of potato. Potato cultivars namely Diamant, Desiree, Herms, Lady Joy, Lady Rossetta, Nicola, Spunta and Valor were variably susceptible to Ralstonia solanacearum, the causal pathogen of brown rot disease. Herms cultivar was the least susceptible. Application of ammonium sulfate, potassium sulfate, Urea, and calcium superphos-phate to infested soil as a single amendment re-duced disease incidence. Application of calcium superphosphate was the most effective treatment. The bioagents Pseudomonas fluorescens, Pseu-domonas putida and Bacillus subtilis were effec-tive in controlling disease when were used sepa-rately and Pseudomonas putida was the most effi-cient. Foliar spraying with different inducers sin-gly [salicylic acid, di-potassium hydrogen phos-phate and tri-potassium phosphate] reduced the disease incidence. Tri-potassium phosphate was the most effective against the disease. Therefore, a management programme was suggested including cultivar Herms, calcium superphosphate, Pseudo-monas putida and tri-potassium phosphate, as in-tegrated treatment. Rotation of these agents showed high effectiveness to disease control as well on the yield increase.
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 [-]BIOLOGICAL CONTROL OF SOIL -BORNE FUNGAL PATHOGENS
2019
Magdy Madkour | M. Afifi | E. Metry | I. Ismail
Seventeen bacterial isolates have been successfully isolated and purified from soil rhizosphere samples collected from different agricultural areas Buhayra, Sharqia and Alqilyubia of Egypt, and screened for production of chitinase enzymes had the highest chitinolytic activities amongst those investigated. Isolate S3-C and S1-C were Identified by biochemical, physiological tests and 16s rRNA gene primer as Bacillus cereus S3C, Gene Bank NCBI accession MK185696 and Bacillus cereus S1C accession MK185697. The production of chitinase by B.cereus S3C and Bacillus cereus S1C was optimized using colloidal chitin medium amended with 1% colloidal chitin at 30°C after five days of incubation. B.cereus S3C had potential for cell wall lysis of many phytopathogenic fungi tested such as Fusarium oxysporum and Rhizoctonia solani Potato phytopathogenic fungi by in vitro antagonistic test. The addition of B. cereus S3C chitinase was more effective than that of B.cereus S1C in increasing the resistance of Potato plants infected with various Soil- borne phytopathogenic fungi.
اظهر المزيد [+] اقل [-]APPLICATION OF SOME STRAINS OF FLUORESCENT PSEUDOMONADS IN MANAGING ROOT-INFECTING PATHOGENS OF MAIZE
2018
O. Abdel Azeez | Enas Hassan | E. El-Assiuty | E. Ramadan
Possibility of manipulating some of the efficient strains of fluorescent pseudomonads to manage the root-infecting pathogens of maize was studied throughout this study. Out of 110 isolates 24 of Pseudomonas species, recovered from the plant rhizosphere showed to have inhibitory effect against two major root-infecting pathogens of maize, namely Cephalosporium maydis and Fusarium verticillioides in vitro. Pot experiment revealed that just 4 isolates could reduce infection with both pathogens and enhance the plant growth as well. Based on the genotypic identifications of these four isolates showed that they were: Pseudomonas putida strain Pau9, P. putida strainPau11, P. putida strain Psf3 and P. aeruginosa strain Psf9.
اظهر المزيد [+] اقل [-]SUSCEPTIBILITY OF DESERT LOCUST, SCHISTOCERCA GREGARIA (ORTHOPTERA: ACRIDIDAE) TO BACILLUS CEREUS ISOLATED FROM EGYPT
2018
M. Reda | T. Mashtoly | M. El-Zemaity | A. Abolmaaty | G. Abdelatef | A. Marzouk
Examination was done at preliminary bracketing bioassay on one old 4th nymphal instar of desert locust. Results showed that two isolates, namely NDL1 and NDL2 were having highly potentiality as entomopathogenic bioagents. Thirty isolates were isolated from dead/ infected nymphs of desert locust occurred in raring cages at Department of Locust and Grasshoppers Research, Plant Protection Research Institute, Agricultural Research Center, Dokki, Giza, Egypt. Molecular identification of isolated bacteria was done using universal primers of 16s rRNA, followed by DNA sequencing. Nucleotides were blasted at (https://www.ncbi. nlm.nih.gov /genbank/) to recognize that NDL1 and NDL2 isolates were two different isolates of Bacillus cereus with a high similarity (100%). Susceptibility of 4th nymphal instar of Schistocerca gregaria (Forskal) to the isolated B. cereus was determined using two bioassay procedures, Leaf-dip and per os. The insecticidal activity of both isolates against locust nymph in leaf dipping showed that NDL2 was more efficient than NDL1. However, the opposite trend was observed in using per os. Both Isolates have the potential to be a successful biocidal agent to control desert locust.
اظهر المزيد [+] اقل [-]Physiological response of strawberry grown in root-knot nematode infested soil under different safety control applications
2011
Mahdy, M.E. | Midan, S.A.
The evaluate some safety treatments including: mulching, tunnels, natural yeast extract, antioxidant and two rhizobacteria Serratia marcescens and Pseudomonas fluorescens towards root-knot nematode Meloidogyne spp. on strawberry plant grown in naturally infested soil and consequently their probable effects on growth parameters, chemical components and yield of strawberry compared to untreated control. Results of this study confirmed that all used treatments, significantly reduced all related nematode parameters i.e. number of galls/root system; number of egg masses/root system as well as number of juveniles/250 g soil (either after 2 or 4 months) when compared to plants grown in the naturally infested soil only. The highest percentage of reduction in all related nematode parameters were noticed after 4 months. Mulching, S. marcescens, P. fluorescens and tunnels, played an important role in reducing the percentage of nematode parameters. Mulching and S. marcescens reduced the percentage of gall numbers/root system by 77%, followed by tunnels by 75% and P. fluorescens by 70%. S. marcescens reduced the percentage of egg masses/root system by 80% followed by P. fluorescens by 78% and mulching by 76%. Results indicated that the soil treated with mulching, also significantly reduced the percent age of juvenile numbers/250 g soil by 79% followed by S. marcescens by 73%. . Results revealed that all previous treatments significantly increased the early and total yield. Our results confirmed that, the rhizobacterium S. marcescens came in the first rank as a promoter of all related plant growth characters, followed by tunnels and mulching treatments. Results confirmed that also the antioxidants, are considered the effective one in enhancing the activities of peroxidase and phenoloxidase as well as T:S.S% and V.C followed by the natural yeast extract.
اظهر المزيد [+] اقل [-]