Journal of chemical and pharmaceutical research, 2016
Field experiments were carried out at the experimental Station of National Research Center Nubari... more Field experiments were carried out at the experimental Station of National Research Center Nubaria region, Behira Government, Egypt, to investigate the effect of different levels of nitrogen fertilizer, tryptophan and their interaction on the growth, productivity and some chemical constituents of green onion plant (Allium cepa L. cv. Giza 6)at 48 and 63 days after sowing (stage A and B respectively). Obtained results indicated that both nitrogen and tryptophan application significantly promoted the growth criteria of green onion: shoot length, white part length, bulb diameter, number of leaves, fresh and dry weight of onion plant at two vegetative stages. The increase in growth criteria was concomitant with increases in photosynthetic pigments, oil percentage, absorbed nitrogen, total nitrogen, total protein, total free amino acids and indoles content. Also, the results cleared decrease in the total soluble salts (TSS). It was noted that 30kgfed-1 nitrogen and 50 mg/L tryptophan caused the highest increases in all examined growth parameters of onion plants at both growth stages. It means that tryptophan amino acid application reduced recommended nitrogen dose at rate 75% and consequently reduced nitrogen accumulation and cost.
Haggag, W. M., Kansoh, A. L., and Aly, A. M. 2006. Proteases From Talaromyces flavus and Trichode... more Haggag, W. M., Kansoh, A. L., and Aly, A. M. 2006. Proteases From Talaromyces flavus and Trichoderma harzianum: Purification , Characterization and Antifungal Activity Against Brown Spot Disease on Faba Bean. Plant Pathol Bull. 15: 231-239. Protease were produced by Trichoderma harzianumand Talaromyces flavuswhen its were grown in the presence of casein. Proteases from the culture filtrate of T. harzianum and T. flavus were purified and tested for their antifungal activity against brown spot disease caused by Botrytis fabae on faba bean. The enzymes were purified in a 2-step procedure involving ammonium sulfate precipitation and Sephadex G-200 gel permeation chromatography. Both enzymes have an optimum temperature of 30 and optimal pH value of 6.5. T. flavus exhibited high levels of extracellular protease activity compared with T. harzianum. Germination and growth rate, extracellular polygalacturonase (PGase) and carboxymethyl cellulase (CMCase) activities of Botrytis fabae were inhibited by the purified protease at a concentration of 40-120 U/ml. Growth and extracellular production of B. fabae were completely inhibited by the protease enzyme of T. flavus at a concentration of 80 U/ml, while protease from T. harzianum was effective at 120 U/ml. Proteases were effective in reducing brown spot disease severity and pathogen sporulation on faba bean leaves inoculated with B. fabae. Proteases at a low concentration of 80 U/ml inhibited B. fabae on leaf surface, as determined by Scanning Electron Microscope (SEM) examination. When enzymes were applied as a foliar spray on faba bean plants grown under natural infested field conditions, the disease incidence was greatly reduced. Protease from T. flavus at 80 U/ml was more significant in reducing disease incidence on leaves and pod and increased pod yield /plant. These results indicated that protease can be a safe biodegradable biocontrol agent for control of brown spot disease on fabae bean .
Agriculture and Biology Journal of North America, May 1, 2010
Mango (Mangifera indica L.) is universally considered one of the most important fruit crop in Egy... more Mango (Mangifera indica L.) is universally considered one of the most important fruit crop in Egypt. Egypt produces 232,000 tone of mangos annually and exports moderate amounts (1500 tones) to 20 countries in the near East and Europe, FAO, 2000. It is expected that commercial and backyard plantings of mango trees will continue to increase. Mango suffers from several diseases at all stages of its life. All the parts of the plant, namely, trunk, branch, twig, leaf, petiole, flower and fruit are attacked by a number of pathogens including fungi, bacteria and algae. They cause several kinds of rot, die back, anthracnose, malformation, scab, necrosis, blotch, spots, mildew, etc. This fact sheet concentrates on the symptoms of the important mango diseases, the weather conditions conducive to disease development, and methods for control.
Mesquite (Prosopis pallida (Wildenow) Kunth) is a drought-tolerant tree widely distributed in the... more Mesquite (Prosopis pallida (Wildenow) Kunth) is a drought-tolerant tree widely distributed in the northern Pacific Coast of South America. This species prevents soil erosion, provides shade, conserves prairies, supports bee nutrition, and provides fruits for human and animal consumption. Since the spring of 2004, bark lesions and bleeding cankers were observed on trunks and branches of 70% of declining mesquite trees in some parks at Ica in southern Peru. Badly affected trees were killed by the disease. Isolations were made from the edge of necrotic lesions of the inner bark and roots using PARPH medium (2) and incubated at 22°C for 7 days. A Phytophthora species was consistently isolated from lesions of 10 mesquite trees, and six pure cultures (PS-87-PS-92) were obtained by transferring hyphal tips and characterized. Colonies were stellate on V8 juice agar (VJA; 2 g CaCO 3 , 200 ml of V8 juice, and 15 g of agar in 800 ml of distilled water), uniform to slightly radiate on corn meal agar (Oxoid Ltd., London, England), and knotty on PDA (Biokar Diagnostics, Beauvais, France). On VJA at 22°C, the average radial growth rate for the six isolates was 1.7 mm per day. Colonies grew slowly at 5 and 25°C with 0.4 and 0.7 mm per day growth rate, respectively. There was no growth at 30°C. Catenulate hyphal swellings formed on VJA and liquid media (1.5% sterile soil extract). Sporangia were persistent, ovoid to obpyriform, semipapillate with narrow exit pores (<5.0 µm in diameter), 32.3 to 39.7 × 21.0 to 27.2 µm, with a length/width ratio of 1.4:1 to 1.6:1. Sporangia were produced by cutting 5-mm disks from the advancing margin of a colony on VJA and adding disks to 10 ml of 1.5% sterile soil extract for 4 to 5 days at 22°C under fluorescent light. Isolates were homothallic with spherical oogonia, 32 to 35 µm in width with paragynous antheridia, and aplerotic oospores, 26 to 31 µm. These characteristics fit the descriptions of Phytophthora syringae (Kleb.) Kleb. (1). Sequences of the internal transcribed spacer regions on the isolates and comparison with other sequences in GenBank showed that they were identical to P. syringae (Accession No. AJ854297 from Citrus limon). In 2005, two methods were used to inoculate mesquite with two isolates. One method used two 20mm-diameter branches of five 5-year-old mesquite trees where a 5-mm wound was made with a cork borer and a 5-mm block of the agar culture was placed under the bark and sealed with Parafilm. Another method used 10 4-month-old potted plants that received a 30-ml drench of a 10 4 zoospores/ml suspension per plant. Controls received clean agar blocks and a sterile water drench for 10 control pots. Two weeks after inoculation, black areas and resinosis were observed around inoculated wounds. Inoculated branches produced cankers of 4.7 to 6.8 cm 2 , 4 weeks after inoculations. Twenty days after inoculation of roots, wilting and root rots of seedlings occurred. No symptoms were found on the control plants. P. syringae was reisolated from the diseased branches and root rots and pure cultures were established. This test was repeated for both methods with similar results. To our knowledge, this is the first report of P. syringae in Peru and the first description of this pathogen on mesquite worldwide.
Several diseases have been reported to affect sugar beet plants. Damping-off and root-rot disease... more Several diseases have been reported to affect sugar beet plants. Damping-off and root-rot diseases of sugar beet are the most important diseases that attack both seedlings and adult plants causing serious losses in crop productivity and quality. Rhizoctonia solani is one of the main causal organisms for pre, post emergence damping-off and root-rot diseases. In laboratory experiments using PDA medium, seven different biocontrol agents (Trichoderma harzianum, Pseudomonas fluorescens, Pseudomonas putida, Brevibacillus brevis, Bacillus megaterium, Paenibacillus polymyxa and Streptomyces sp.) showed an inhibitory effects on the linear growth of R. solani. T. harzianum was the most effective bioagent in reducing the linear growth of R. solani followed by P. fluorescens, P. putida, B. megaterium, P. polymyxa, B. brevis and Streptomyces sp respectively. Under greenhouse conditions, the most effective biocontrol agent was B. brevis against R. solani, followed by Streptomyces sp., B. megaterium, T. harzianum, P. polymyxa, P. putida and P. fluorescens respectively. Bioagents treatments resulted in significant increase in soluble protein contents with significant increase in the phenol content, polyphenol-oxidase, peroxidase and chitinase. The different growth parameters, plant root length, dry root weight, leaves dry weight and number of leaves per plant were higher in case of the treated seedlings with antagonistic organisms than with untreated seedlings. Results revealed that the most effective biocontrol agent was Streptomyces sp. concerning the number of survival plants, followed by P. fluorescens, P. putida, B. megaterium, T. harzianum, B. brevis and P. polymyxa respectively. The growth parameters results indicated that significant differences were observed among most of the variables measured for the biocontrol treatments compared with the untreated control.
International Journal of Agriculture Innovations and Research, 2014
In summer 2010, extensive fruit blight was observed on eggplant plants (Solanum melongena) Cv. 'B... more In summer 2010, extensive fruit blight was observed on eggplant plants (Solanum melongena) Cv. 'Black Magic', Classic', in a commercial farm in Tahreer province, Bohara Governorate (Egypt).
In May 2006, leaf spots were observed on approximately 60% of 8-year-old pistachio (Pistacia vera... more In May 2006, leaf spots were observed on approximately 60% of 8-year-old pistachio (Pistacia vera L.) trees in an orchard located at Rhafah, north of Sinai, Egypt. These spots were typically circular, or occasionally irregular, with white-to-light tan or gray centers and a purple or brown border measuring 1 to 5 mm in diameter, or occasionally larger on the upper leaf surface. A narrow, brown border surrounded the spot, and with age, the lesion cracked. Spots occasionally turned brown and closed to form blotches. Fungal isolates from the leaf spots were identified as Septoria pistaciae on the basis of characteristics of pycnidia and conidia. From the leaf spots, numerous black pycnidia were found that produced hyaline conidia, 3 to 7 septate, generally filiform although tapering at one end, and measuring 46 to 75 × 3 to 4 μm. Pycnidia were dark, separate, globe shaped with an ostiole from which conidia were extruded, and erupted through the surface of infected plant tissue. Conidia were produced on short conidiophores. Single conidial isolations onto 2% malt agar consistently formed slow-growing, dark green colonies. To confirm the pathogenicity of the isolate of S. pistaciae, a suspension of 5 × 105 conidia per ml in water was applied at 1 ml per leaf to 20 leaves of 10 rooted cuttings of pistachio trees in 30-cm pots. Ten controls were misted with water only. All plants were covered with plastic bags for 48 h on a greenhouse bench. Greenhouse temperatures ranged from 15 to 20°C with a 16-h photoperiod. After 6 days, all inoculated plants developed symptoms, and the fungus was reisolated from lesions. No symptoms were observed on control plants. S. pistaciae was previously reported on pistachio in Texas and Arizona (2,3). Reports included mention of its occurrence in the United States (California), Asia (Armenia Republic of Georgia, India, Israel, Kazakhstan, Kirgizstan, Syria, Turkey, Turkmenistan, and Uzbekistan), and Europe (Albania, France, Greece, Italy, and Portugal) (1). To our knowledge, this is the first report of Septoria leaf spots of pistachio in Egypt. References: (1) T. Andrianova and D. Minler. Septoria pistaciae. Page 159 in: IMI Descriptions of Fungi and Bacteria. CAB International, Wallingford, UK. 2004. (2) A. Chitzanidis. Ann. Inst. Phytopathol. Benaki 10:29, 1956. (3) D. J. Young and T. Michailides. Plant Dis. 73:775, 1989.
Yet a comprehensive analysis of how climate change would influence the dissemination of plant dis... more Yet a comprehensive analysis of how climate change would influence the dissemination of plant diseases and impact the primary production in most agricultural ecosystems is at the moment missing. There are hardly any studies on the impacts of climate change on the dissemination of diseases in field crops. Multifactor studies under realistic in situ field situations ecosystems are a way forward. No doubt, the realistic assessment of CO 2 free air or air enriched with increasing CO 2 and O 3 concentrations always incorporating spectral reflectance measures on plant growth. Ecologists are now addressing the role of plant disease on the varied ecosystem processes and the challenge of scaling up from individual infection probabilities to epidemics and broader impacts. Plant diseases are considered an important component of plant and environmental health that might be arise through either infection with biotic pathogens as well as abiotic factors. Biotic plant diseases are caused by organisms such as fungi, bacteria, viruses, nematodes, phytoplasmas as well as with parasites. Abiotic diseases, on the other hand, are for all time associated with chemical and physical climatic factors, such as temperature or moisture extremes, farming factors such as nutrient deficiencies, mineral toxicities and pollution. At the genomic level, advances in technologies for the highthroughput analysis of gene expression have made it possible to begin discriminating responses to different biotic and abiotic stressors and potential trade-offs in responses. Most plant diseases models use deferent climatic variables and operate at a deferent spatial and temporal scale than do the global climate ones. The current review describes environmental factors that influence severity of crop disease epidemics in order to assess the predicted impacts of climate change on plant growth and their harvest as well as on the severity of disease epidemics. Effects of a changing climate on chemical and biological controls of plant diseases are also discussed in the context of the changing global outlooks on environmental demands for the future.
Exposing a wild-type culture of Trichoderma harzianum to gamma irradiation induced two stable sal... more Exposing a wild-type culture of Trichoderma harzianum to gamma irradiation induced two stable salt-tolerant mutants (Th50M6 and Th50M11). Under saline conditions, both mutants greatly surpassed their wild type strain in growth rate, sporulation and biological proficiency against Fusarium oxysporum, the causal agent of tomato wilt disease. Tolerant T. harzianum mutants detained a capability to grow and convinced sporulation in growth media containing up to 69 mM NaCl. In comparison with their parent strain, characterization of both mutants confirmed that they have reinforced contents of proline and hydroxyproline, relatively higher sodium content compared to potassium, calcium or magnesium contents, higher level of total phenols. Electrophoretic analysis of total soluble proteins in the salt tolerance mutant Th50M6 showed different bands accumulated in response to 69 mM NaCl. Data also showed that mutants produce certain active metabolites, such as chitinases, cellulases, β-galactosidases, as well as, some antibiotics i.e., trichodermin, gliotoxin and gliovirin. Trichoderma mutants significantly reduced wilt disease incidence and improved yield and mineral contents of tomato plants under both saline and non-saline soil conditions, as well as, under infested and natural conditions. T. harzianum mutants were also more efficient in dropping the F. oxysporum growth in rhizosphere compared to the wild type strain. Population density of both mutants in rhizosphere far exceeded that of T. harzianum wild type strain.
International journal of pharma and bio sciences, 2016
Wheat is the most important cereal crop, a staple food for more than one third of population worl... more Wheat is the most important cereal crop, a staple food for more than one third of population world. Recently, there is increased interest in naturally produced active compounds as alternatives of fungicide and improve plant stress. Blue-green algae (cyanobacteria) secondary metabolites have a diverse antagonistic activity that lead to disintegration of microbial growth and improve plant resistant against stress. So, this study was conducted to evaluate the antifungal activities of Oscillatoria agardhii in retarding the growth of wheat pathogenic fungal species and improve resistance to biotic and abiotic stress under stress conditions in compared to the natural environment. Based on zone of inhibition formation and Minimal Inhibitory Concentrations (MIC), it was concluded that the extracts of O. agardhii had significant antifungal and antimicrobial efficacy. Experiment was conducted under natural conditions at farmer’s field in middle of Sinai which saline soil and compared in a nat...
Mit Hilfe genetischer Marker wurde die grose Variabilitat der Resistenz 24 agyptischer Gersten-Li... more Mit Hilfe genetischer Marker wurde die grose Variabilitat der Resistenz 24 agyptischer Gersten-Linien und -Landrassen gegenuber Blattrost und Netzfleckenkrankheit untersucht. Insbesondere die Landrassen erwiesen sich als beachtenswerte genetische Ressource fur die zukunftige Zuchtung widerstandsfahiger Gerstensorten.
Weed control is consider the major obstacle for the growers in the organic farming. Lower plant p... more Weed control is consider the major obstacle for the growers in the organic farming. Lower plant productivity in organic farming mainly related to the poor weed control. It is widely known, in most cases, that losses caused by weeds exceeded the losses from any category of agricultural pests. Under water-stress condition, weeds can reduce crop yields more than 50% through moisture competition alone. In the light of the environmental and toxicological problems created by herbicides, it has become necessary to develop the safety methods for controlling weeds. Soil Solarization, Mulching, Biodegradable Mulch, Natural Herbicides, Hot Water, and Agronomic Practices have been successfully adopted in many countries as safe methods for controlling weeds in the organic farming. In addition, there are some promising new and non-traditional measures such as Fresnel Lens, Electrical Weed Control, Lasers, etc which could be employed for controlling the weeds in organic farming. Also the agronomic...
Journal of chemical and pharmaceutical research, 2016
Field experiments were carried out at the experimental Station of National Research Center Nubari... more Field experiments were carried out at the experimental Station of National Research Center Nubaria region, Behira Government, Egypt, to investigate the effect of different levels of nitrogen fertilizer, tryptophan and their interaction on the growth, productivity and some chemical constituents of green onion plant (Allium cepa L. cv. Giza 6)at 48 and 63 days after sowing (stage A and B respectively). Obtained results indicated that both nitrogen and tryptophan application significantly promoted the growth criteria of green onion: shoot length, white part length, bulb diameter, number of leaves, fresh and dry weight of onion plant at two vegetative stages. The increase in growth criteria was concomitant with increases in photosynthetic pigments, oil percentage, absorbed nitrogen, total nitrogen, total protein, total free amino acids and indoles content. Also, the results cleared decrease in the total soluble salts (TSS). It was noted that 30kgfed-1 nitrogen and 50 mg/L tryptophan caused the highest increases in all examined growth parameters of onion plants at both growth stages. It means that tryptophan amino acid application reduced recommended nitrogen dose at rate 75% and consequently reduced nitrogen accumulation and cost.
Haggag, W. M., Kansoh, A. L., and Aly, A. M. 2006. Proteases From Talaromyces flavus and Trichode... more Haggag, W. M., Kansoh, A. L., and Aly, A. M. 2006. Proteases From Talaromyces flavus and Trichoderma harzianum: Purification , Characterization and Antifungal Activity Against Brown Spot Disease on Faba Bean. Plant Pathol Bull. 15: 231-239. Protease were produced by Trichoderma harzianumand Talaromyces flavuswhen its were grown in the presence of casein. Proteases from the culture filtrate of T. harzianum and T. flavus were purified and tested for their antifungal activity against brown spot disease caused by Botrytis fabae on faba bean. The enzymes were purified in a 2-step procedure involving ammonium sulfate precipitation and Sephadex G-200 gel permeation chromatography. Both enzymes have an optimum temperature of 30 and optimal pH value of 6.5. T. flavus exhibited high levels of extracellular protease activity compared with T. harzianum. Germination and growth rate, extracellular polygalacturonase (PGase) and carboxymethyl cellulase (CMCase) activities of Botrytis fabae were inhibited by the purified protease at a concentration of 40-120 U/ml. Growth and extracellular production of B. fabae were completely inhibited by the protease enzyme of T. flavus at a concentration of 80 U/ml, while protease from T. harzianum was effective at 120 U/ml. Proteases were effective in reducing brown spot disease severity and pathogen sporulation on faba bean leaves inoculated with B. fabae. Proteases at a low concentration of 80 U/ml inhibited B. fabae on leaf surface, as determined by Scanning Electron Microscope (SEM) examination. When enzymes were applied as a foliar spray on faba bean plants grown under natural infested field conditions, the disease incidence was greatly reduced. Protease from T. flavus at 80 U/ml was more significant in reducing disease incidence on leaves and pod and increased pod yield /plant. These results indicated that protease can be a safe biodegradable biocontrol agent for control of brown spot disease on fabae bean .
Agriculture and Biology Journal of North America, May 1, 2010
Mango (Mangifera indica L.) is universally considered one of the most important fruit crop in Egy... more Mango (Mangifera indica L.) is universally considered one of the most important fruit crop in Egypt. Egypt produces 232,000 tone of mangos annually and exports moderate amounts (1500 tones) to 20 countries in the near East and Europe, FAO, 2000. It is expected that commercial and backyard plantings of mango trees will continue to increase. Mango suffers from several diseases at all stages of its life. All the parts of the plant, namely, trunk, branch, twig, leaf, petiole, flower and fruit are attacked by a number of pathogens including fungi, bacteria and algae. They cause several kinds of rot, die back, anthracnose, malformation, scab, necrosis, blotch, spots, mildew, etc. This fact sheet concentrates on the symptoms of the important mango diseases, the weather conditions conducive to disease development, and methods for control.
Mesquite (Prosopis pallida (Wildenow) Kunth) is a drought-tolerant tree widely distributed in the... more Mesquite (Prosopis pallida (Wildenow) Kunth) is a drought-tolerant tree widely distributed in the northern Pacific Coast of South America. This species prevents soil erosion, provides shade, conserves prairies, supports bee nutrition, and provides fruits for human and animal consumption. Since the spring of 2004, bark lesions and bleeding cankers were observed on trunks and branches of 70% of declining mesquite trees in some parks at Ica in southern Peru. Badly affected trees were killed by the disease. Isolations were made from the edge of necrotic lesions of the inner bark and roots using PARPH medium (2) and incubated at 22°C for 7 days. A Phytophthora species was consistently isolated from lesions of 10 mesquite trees, and six pure cultures (PS-87-PS-92) were obtained by transferring hyphal tips and characterized. Colonies were stellate on V8 juice agar (VJA; 2 g CaCO 3 , 200 ml of V8 juice, and 15 g of agar in 800 ml of distilled water), uniform to slightly radiate on corn meal agar (Oxoid Ltd., London, England), and knotty on PDA (Biokar Diagnostics, Beauvais, France). On VJA at 22°C, the average radial growth rate for the six isolates was 1.7 mm per day. Colonies grew slowly at 5 and 25°C with 0.4 and 0.7 mm per day growth rate, respectively. There was no growth at 30°C. Catenulate hyphal swellings formed on VJA and liquid media (1.5% sterile soil extract). Sporangia were persistent, ovoid to obpyriform, semipapillate with narrow exit pores (<5.0 µm in diameter), 32.3 to 39.7 × 21.0 to 27.2 µm, with a length/width ratio of 1.4:1 to 1.6:1. Sporangia were produced by cutting 5-mm disks from the advancing margin of a colony on VJA and adding disks to 10 ml of 1.5% sterile soil extract for 4 to 5 days at 22°C under fluorescent light. Isolates were homothallic with spherical oogonia, 32 to 35 µm in width with paragynous antheridia, and aplerotic oospores, 26 to 31 µm. These characteristics fit the descriptions of Phytophthora syringae (Kleb.) Kleb. (1). Sequences of the internal transcribed spacer regions on the isolates and comparison with other sequences in GenBank showed that they were identical to P. syringae (Accession No. AJ854297 from Citrus limon). In 2005, two methods were used to inoculate mesquite with two isolates. One method used two 20mm-diameter branches of five 5-year-old mesquite trees where a 5-mm wound was made with a cork borer and a 5-mm block of the agar culture was placed under the bark and sealed with Parafilm. Another method used 10 4-month-old potted plants that received a 30-ml drench of a 10 4 zoospores/ml suspension per plant. Controls received clean agar blocks and a sterile water drench for 10 control pots. Two weeks after inoculation, black areas and resinosis were observed around inoculated wounds. Inoculated branches produced cankers of 4.7 to 6.8 cm 2 , 4 weeks after inoculations. Twenty days after inoculation of roots, wilting and root rots of seedlings occurred. No symptoms were found on the control plants. P. syringae was reisolated from the diseased branches and root rots and pure cultures were established. This test was repeated for both methods with similar results. To our knowledge, this is the first report of P. syringae in Peru and the first description of this pathogen on mesquite worldwide.
Several diseases have been reported to affect sugar beet plants. Damping-off and root-rot disease... more Several diseases have been reported to affect sugar beet plants. Damping-off and root-rot diseases of sugar beet are the most important diseases that attack both seedlings and adult plants causing serious losses in crop productivity and quality. Rhizoctonia solani is one of the main causal organisms for pre, post emergence damping-off and root-rot diseases. In laboratory experiments using PDA medium, seven different biocontrol agents (Trichoderma harzianum, Pseudomonas fluorescens, Pseudomonas putida, Brevibacillus brevis, Bacillus megaterium, Paenibacillus polymyxa and Streptomyces sp.) showed an inhibitory effects on the linear growth of R. solani. T. harzianum was the most effective bioagent in reducing the linear growth of R. solani followed by P. fluorescens, P. putida, B. megaterium, P. polymyxa, B. brevis and Streptomyces sp respectively. Under greenhouse conditions, the most effective biocontrol agent was B. brevis against R. solani, followed by Streptomyces sp., B. megaterium, T. harzianum, P. polymyxa, P. putida and P. fluorescens respectively. Bioagents treatments resulted in significant increase in soluble protein contents with significant increase in the phenol content, polyphenol-oxidase, peroxidase and chitinase. The different growth parameters, plant root length, dry root weight, leaves dry weight and number of leaves per plant were higher in case of the treated seedlings with antagonistic organisms than with untreated seedlings. Results revealed that the most effective biocontrol agent was Streptomyces sp. concerning the number of survival plants, followed by P. fluorescens, P. putida, B. megaterium, T. harzianum, B. brevis and P. polymyxa respectively. The growth parameters results indicated that significant differences were observed among most of the variables measured for the biocontrol treatments compared with the untreated control.
International Journal of Agriculture Innovations and Research, 2014
In summer 2010, extensive fruit blight was observed on eggplant plants (Solanum melongena) Cv. 'B... more In summer 2010, extensive fruit blight was observed on eggplant plants (Solanum melongena) Cv. 'Black Magic', Classic', in a commercial farm in Tahreer province, Bohara Governorate (Egypt).
In May 2006, leaf spots were observed on approximately 60% of 8-year-old pistachio (Pistacia vera... more In May 2006, leaf spots were observed on approximately 60% of 8-year-old pistachio (Pistacia vera L.) trees in an orchard located at Rhafah, north of Sinai, Egypt. These spots were typically circular, or occasionally irregular, with white-to-light tan or gray centers and a purple or brown border measuring 1 to 5 mm in diameter, or occasionally larger on the upper leaf surface. A narrow, brown border surrounded the spot, and with age, the lesion cracked. Spots occasionally turned brown and closed to form blotches. Fungal isolates from the leaf spots were identified as Septoria pistaciae on the basis of characteristics of pycnidia and conidia. From the leaf spots, numerous black pycnidia were found that produced hyaline conidia, 3 to 7 septate, generally filiform although tapering at one end, and measuring 46 to 75 × 3 to 4 μm. Pycnidia were dark, separate, globe shaped with an ostiole from which conidia were extruded, and erupted through the surface of infected plant tissue. Conidia were produced on short conidiophores. Single conidial isolations onto 2% malt agar consistently formed slow-growing, dark green colonies. To confirm the pathogenicity of the isolate of S. pistaciae, a suspension of 5 × 105 conidia per ml in water was applied at 1 ml per leaf to 20 leaves of 10 rooted cuttings of pistachio trees in 30-cm pots. Ten controls were misted with water only. All plants were covered with plastic bags for 48 h on a greenhouse bench. Greenhouse temperatures ranged from 15 to 20°C with a 16-h photoperiod. After 6 days, all inoculated plants developed symptoms, and the fungus was reisolated from lesions. No symptoms were observed on control plants. S. pistaciae was previously reported on pistachio in Texas and Arizona (2,3). Reports included mention of its occurrence in the United States (California), Asia (Armenia Republic of Georgia, India, Israel, Kazakhstan, Kirgizstan, Syria, Turkey, Turkmenistan, and Uzbekistan), and Europe (Albania, France, Greece, Italy, and Portugal) (1). To our knowledge, this is the first report of Septoria leaf spots of pistachio in Egypt. References: (1) T. Andrianova and D. Minler. Septoria pistaciae. Page 159 in: IMI Descriptions of Fungi and Bacteria. CAB International, Wallingford, UK. 2004. (2) A. Chitzanidis. Ann. Inst. Phytopathol. Benaki 10:29, 1956. (3) D. J. Young and T. Michailides. Plant Dis. 73:775, 1989.
Yet a comprehensive analysis of how climate change would influence the dissemination of plant dis... more Yet a comprehensive analysis of how climate change would influence the dissemination of plant diseases and impact the primary production in most agricultural ecosystems is at the moment missing. There are hardly any studies on the impacts of climate change on the dissemination of diseases in field crops. Multifactor studies under realistic in situ field situations ecosystems are a way forward. No doubt, the realistic assessment of CO 2 free air or air enriched with increasing CO 2 and O 3 concentrations always incorporating spectral reflectance measures on plant growth. Ecologists are now addressing the role of plant disease on the varied ecosystem processes and the challenge of scaling up from individual infection probabilities to epidemics and broader impacts. Plant diseases are considered an important component of plant and environmental health that might be arise through either infection with biotic pathogens as well as abiotic factors. Biotic plant diseases are caused by organisms such as fungi, bacteria, viruses, nematodes, phytoplasmas as well as with parasites. Abiotic diseases, on the other hand, are for all time associated with chemical and physical climatic factors, such as temperature or moisture extremes, farming factors such as nutrient deficiencies, mineral toxicities and pollution. At the genomic level, advances in technologies for the highthroughput analysis of gene expression have made it possible to begin discriminating responses to different biotic and abiotic stressors and potential trade-offs in responses. Most plant diseases models use deferent climatic variables and operate at a deferent spatial and temporal scale than do the global climate ones. The current review describes environmental factors that influence severity of crop disease epidemics in order to assess the predicted impacts of climate change on plant growth and their harvest as well as on the severity of disease epidemics. Effects of a changing climate on chemical and biological controls of plant diseases are also discussed in the context of the changing global outlooks on environmental demands for the future.
Exposing a wild-type culture of Trichoderma harzianum to gamma irradiation induced two stable sal... more Exposing a wild-type culture of Trichoderma harzianum to gamma irradiation induced two stable salt-tolerant mutants (Th50M6 and Th50M11). Under saline conditions, both mutants greatly surpassed their wild type strain in growth rate, sporulation and biological proficiency against Fusarium oxysporum, the causal agent of tomato wilt disease. Tolerant T. harzianum mutants detained a capability to grow and convinced sporulation in growth media containing up to 69 mM NaCl. In comparison with their parent strain, characterization of both mutants confirmed that they have reinforced contents of proline and hydroxyproline, relatively higher sodium content compared to potassium, calcium or magnesium contents, higher level of total phenols. Electrophoretic analysis of total soluble proteins in the salt tolerance mutant Th50M6 showed different bands accumulated in response to 69 mM NaCl. Data also showed that mutants produce certain active metabolites, such as chitinases, cellulases, β-galactosidases, as well as, some antibiotics i.e., trichodermin, gliotoxin and gliovirin. Trichoderma mutants significantly reduced wilt disease incidence and improved yield and mineral contents of tomato plants under both saline and non-saline soil conditions, as well as, under infested and natural conditions. T. harzianum mutants were also more efficient in dropping the F. oxysporum growth in rhizosphere compared to the wild type strain. Population density of both mutants in rhizosphere far exceeded that of T. harzianum wild type strain.
International journal of pharma and bio sciences, 2016
Wheat is the most important cereal crop, a staple food for more than one third of population worl... more Wheat is the most important cereal crop, a staple food for more than one third of population world. Recently, there is increased interest in naturally produced active compounds as alternatives of fungicide and improve plant stress. Blue-green algae (cyanobacteria) secondary metabolites have a diverse antagonistic activity that lead to disintegration of microbial growth and improve plant resistant against stress. So, this study was conducted to evaluate the antifungal activities of Oscillatoria agardhii in retarding the growth of wheat pathogenic fungal species and improve resistance to biotic and abiotic stress under stress conditions in compared to the natural environment. Based on zone of inhibition formation and Minimal Inhibitory Concentrations (MIC), it was concluded that the extracts of O. agardhii had significant antifungal and antimicrobial efficacy. Experiment was conducted under natural conditions at farmer’s field in middle of Sinai which saline soil and compared in a nat...
Mit Hilfe genetischer Marker wurde die grose Variabilitat der Resistenz 24 agyptischer Gersten-Li... more Mit Hilfe genetischer Marker wurde die grose Variabilitat der Resistenz 24 agyptischer Gersten-Linien und -Landrassen gegenuber Blattrost und Netzfleckenkrankheit untersucht. Insbesondere die Landrassen erwiesen sich als beachtenswerte genetische Ressource fur die zukunftige Zuchtung widerstandsfahiger Gerstensorten.
Weed control is consider the major obstacle for the growers in the organic farming. Lower plant p... more Weed control is consider the major obstacle for the growers in the organic farming. Lower plant productivity in organic farming mainly related to the poor weed control. It is widely known, in most cases, that losses caused by weeds exceeded the losses from any category of agricultural pests. Under water-stress condition, weeds can reduce crop yields more than 50% through moisture competition alone. In the light of the environmental and toxicological problems created by herbicides, it has become necessary to develop the safety methods for controlling weeds. Soil Solarization, Mulching, Biodegradable Mulch, Natural Herbicides, Hot Water, and Agronomic Practices have been successfully adopted in many countries as safe methods for controlling weeds in the organic farming. In addition, there are some promising new and non-traditional measures such as Fresnel Lens, Electrical Weed Control, Lasers, etc which could be employed for controlling the weeds in organic farming. Also the agronomic...
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