Journal of Phytopathology and Pest Management (Al-Azhar University)
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Evaluation of some safe alternative agents against the pink stem borer, Sesamia cretica Lederer infesting sugarcane at Sohag governorate, Egypt
Get PDFSome different control methods, mechanical, biological and four plant extracts were tested individually against the pink stem borer, Sesamia critica Lederer (Lepidoptera: Noctuidae) in both plant and ratoon crops of sugarcane during 2018 and 2019 at Sohag governorate, Egypt. Data were recorded on the basis of the percent infestation (dead hearts) of S. critica from April to June, while the infestation reduction percentage and population density were recorded based on the percent of infestation. The results showed that, all the control methods significantly reduced borer infestation as compared with control plots. Data demonstrated that water extracts of marjoram and rosemary achieved the lowest infestation (2.18 - 3.02%) and (1.42 – 2.00%), while the highest infestation was recorded in biological control treatment (18.00 – 13.47%) in two seasons 2018 and 2019 respectively. These results could be used in integrated pest management (IPM) programs for the pink stem borer, Sesamia critica control in sugarcane
Antifungal activity of bioagents and plant extracts against certain fungal diseases of potatoes
Get PDFTwenty-six fungal isolates were obtained from potato plants and tubers growing in different localities in Egypt. The isolates were identified as 11 Rhizoctonia solani, 8 Sclerotinia sclerotiorum and 7 Fusarium spp. The 26 isolates were screened due to their pathogenic capabilities and the most pathogenic isolate among each of the three obtained genera was selected for this study. In vitro studies included the effect of 7 bacterial isolates, 6 Trichoderma isolates, as well as 6 plant extracts at four rates of application against the three fungal pathogens, Trichoderma harzianum (T5) achieved the highest mycelial growth inhibition, followed by T. asperellum (T34) and T. harzianum (T10) isolates. Additionally, Bacillus subtilis (BS2) recorded the best mycelial growth inhibition against the three tested fungi, followed by B. subtilis (BS1) and B.megatirum(BM2). On the subject of plant extracts, garlic extract gave the greatest reduction of the mycelial growth with all rates of application, followed by henna and ginger extracts. Field experiments were conducted during 2018/2019 and 2019/2020 growing seasons to evaluate bioagent activities as well as plant extracts in reducing disease severity caused by the three fore-mentioned pathogenic fungi. Trichoderma harzianum (T5) exhibited the highest disease reduction in vivo, followed by (T34) and Pseudomonas fluorescens (PF2), as compared with the control. Under greenhouse conditions, garlic extract decreased disease severity of both Fusarium sp and S. sclerotiorum, followed by henna and ginger extracts. On the other hand, henna extract came in the first order in reducing disease severity caused by R.solani, followed by ginger and garlic, as compared with the control. On the whole, Trichoderma harzianum (T5) and T. asperellum (T34) were the best treatments, those reduced diseases severity to the greatest extent if compared with the other treatments and the control
Efficacy of biological therapies against onion basal rot caused by Fusarium oxysporum f. sp. cepae under field and storage conditions
Get PDFBasal rot disease of onion is caused by Fusarium oxysporum f. sp. cepae (Hans.) (FOC) economically significant losses wherever onion is grown. Fusarium oxysporum were isolated from diseased onion cultivated in different places of Assiut, Egypt. Efficacy of certain yeasts was evaluated for controlling the basal rot of onion in vitro. Among of the tested isolates, Saccharomyces cerevisiae gave the greatest inhibition (57.74%) and Candida tropicalis (1) significantly exerted the greatest reduction of mycelial growth of F. oxysporum f. sp. cepae (51.18%). Based on the in vitro screening, effective yeasts were evaluated under greenhouse, field and storage conditions. Yeasts were applied by two methods (add the pathogen and antagonistic yeasts to soil before sowing seedling onion, and seedling onion soaking in yeasts for 20 minute). Both methods of inoculation showed substantial impact on disease development and plant growth. Add method caused maximum reduction in plant germination, followed by soaking method as compared to control. Application of fungicide (Captain) as compared brought a remarkable increase in seedling emergence of treated plants inoculated with F. oxysporum as compared to the untreated plants. In conclusion, tested yeasts were useful as an alternative to chemical control of the onion basal rot and to enhanced growth and yield of onion
Control of root rot disease of sugar beet using certain antioxidants and fungicides
Get PDFThis study was carried out to investigate the effect of five chemical inducers i.e. salicylic acid, ascorbic acid, catechol, citric acid and potassium silicate and six fungicides i.e. Actamyl70%, Chlorothalonil 50%, Evito 48%, Shenzy 34%, Pyrus 40% and Fentobein 32.5% in order to control Rhizoctonia solani and Macrophomina phaseolina which infect sugar beet roots. The antioxidants, catechol and salicylic acid achieved the best disease control at all rates of application followed by citric acid and potassium silicate, respectively. Concerning fungicides, Shenzy 34% gave noticeable control in disease reduction followed by Evito 48% and Fentobein 32.5%, respectively. Usage of antioxidants as chemical inducers for enhancing plant resistance and capability of defying diseases is well recommended as fungicide alternatives due to their safe influence on human health. But, fungicides are still the most widespread used compounds in disease management strategies, based on their compliant application, reliable and efficient results than any other safer chemical or natural compound which controls the disease by reducing the losses, not by eradicating the disease in which fungicides can do successfully
Selection of compost-derived actinomycetes with plant-growth promoting and tomato stem rot biocontrol potentialities
Get PDFSeventeen actinomycetes isolates, recovered from 2 composts, were screened for their ability to promote the growth of tomato seedlings and to suppress stem rot disease caused by Sclerotium rolfsii. Tomato cv. Rio Grande seedlings inoculated with S. rolfsii and treated with A2-3, A3-3, A4-3, A5-3, A8-3, A9-3, A1-4, A2-4, A3-4, A4-4, A6-4, and A10-4 actinobacterial isolates showed 23.3-70% less disease severity than the inoculated and untreated controls. A3-3, A2-4, and A4-4 based treatments applied to S. rolfsii-infected tomato seedlings had significantly enhanced all growth parameters as compared to control. The recorded increments were estimated at 35.52-66.6% for height, 37.4-53.4% for the stem diameter, 38.5-95.6% for the aerial part dry weight, and 81.8-151% for the root dry weight. Treatments with A3-3 and A4-4 isolates had increased the majority of tomato growth parameters by 15.8-56.5% over the pathogen-free control. Tomato seedlings treated with A4-3 and A1-4 isolates showed between 35.2-22.8% and 42.3-43.3% higher aerial part dry weight and root dry weight, respectively, as compared to pathogen-free and untreated control. This investigation demonstrated that the tested composts can be explored as potential sources for the isolation of actinomycetes acting as biocontrol and bio-fertilizing agents
Morphological, morphometrical and molecular identification of root-knot nematode (Meloidogyne javanica) infecting banana in Assiut governorate, Egypt
Get PDFPlant-parasitic nematodes are extremely dangerous pests in a variety of economically important crops. Root-knot nematodes (RKN) Meloidogyne spp. are between the major important pests causing serious crops havoc worldwide because of their wide geographical distribution and variety of hosts. Therefore, both of identification that is true and trustworthy of these pests is required for evaluating various suitable management strategies. This study, aimed to characterize morphological, morphometric and molecularly isolate of Meloidogyne related to banana plants. Second-stage juveniles (body length, tail length, stylet length, hyaline terminus length, and DEGO) were used in morphometric and morphological studies and female in perineal patterns. The results revealed that the identified nematode species, Meloidogyne javanica, is the most common root knot nematode species in all three localities. To prove the identification, a polymerase chain reaction (PCR)-based experiment using a species-specific sequence described amplified regions (SCAR) primer series was used. The Fjav/Rjav primer effectively enhanced SCAR markers of 670 bp previously identified in M. javanica. This study confirms the use of an effective and reliable diagnosis of RKN using the three approaches
Control of peanut root and pod rots diseases using certain bioagents
Get PDFTo evaluate the potential of certain bacterial and fungal bioagents against Macrophomina phasolina, Rhizoctonia solani and Fusarium oxysporum which causing peanut root and pod rots diseases. Thirty three fungal isolates obtained from infected plants showing typical symptoms of peanut root and pod rot, collected from different localities in Assiut, Sohag and Minia governorates, Egypt were identified as R. solani, M. phaseolina, F. solani, Aspergillus niger, A. flavus, F. moniliforme, F. equesti and F. semitectum. Pathogenicity tests showed that M. phaseolina No. 4 recorded was the most pathogenic as incited root-rot and pod rot on the tested peanut cultivars NC followed by R. solani No. 6 and F. solani No. 7. Under laboratory conditions, twelve isolates of bacterial bioagents i.e Bacillus subtilis (BS1 and BS2), Bacillus megaterium (BM1 and BM2), Penibacillus polymyxa BP, Pseudomonas fluorescens (PF1 and PF2) and Azotobacter spp. (AZ1, AZ2, AZ3, AZ4 and AZ5), as well as, six isolates of Trichoderma spp. (T5, T7, T8, T9, T10 and T34) were tested to study their effects against the mycelial growth of the causal pathogens isolates i.e. M. phaseolina No. 4, R. solani No. 6 and F. solani No. 7. In vitro, our results showed that seven bacterial isolates (B. subtilis BS1, B. megaterium BM2, B. polymyxa BP, P. fluorescense (PF1 and PF2), Azotobacter spp. (AZ2 and AZ5)) and three isolates of Trichoderma spp. (T7, T10 and T34) gave the highest significant antagonistic effects against the test pathogens. The ten bioagents isolates which exhibited the best inhibition to the pathogenic fungi in vitro were tested in vivo during 2019 and 2020 growing seasons and the results revealed that Trichoderma spp. T34, B. subtilis BS1, P. polymyxa BP, Azotobacter spp. AZ2, B. megaterium BM2 and Trichoderma spp. T10, which tested against M. phaseolina, R. solani and F. solani, gave the highest reduction of both peanut root and pod rots diseases
Molecular detection of stripe rust resistance genes in some Egyptian bread wheat cultivars and promising spring wheat lines
Get PDFStripe rust (yellow rust), caused by Puccinia striiformis f.sp. tritici (Pst), is a serious disease of wheat worldwide. Growing resistant cultivars is the most cost-effective and environmentally friendly approach to control the disease. Fifteen Egyptian wheat cultivars, five advanced lines, and twelve yellow rust (Yr) resistance isogenic lines were evaluated against three of the most prevalent Pst physiological races 224E132, 224E32, and 151E80 in Egypt. Infection types and diseases severity for all wheat genotypes at seedling and adult plant stages were recorded, during two successive seasons 2017/18 and 2018/19. In addition, three Sequence-Tagged Sites (STS) markers and three Simple Sequence Repeat (SSR) markers were used for detection of (Yr5, Yr15, and Yr26) and (Yr10, Yr17, and Yr18), respectively. The results revealed that Sakha-93, Sakha-95, and Misr-3 were the only wheat cultivars that showed moderated to high resistance against the three rust races, in seedling and adult plant stages in both seasons. All tested breeding lines were showed high to moderated resistance against races mixture at adult stage in both seasons. However, only breeding Line-2 and Line-5 were showed high to moderated resistance against the three races in seedling stage. Also, high resistance in both seedling and adult plant stages were observed on isogenic lines Yr5 and Yr15 against tested races. Yr5 was detected in three wheat genotypes including Sakh-95, Misr-3 and Line-2. Yr10 was found only in Sakha-93. Yr17 was existed only in Misr-3 and all breeding lines except Line-1. Yr15 was detected in seven commercial cultivars but it was not detected in any of the breeding lines. However, Yr18, and Yr26 were found in all tested wheat genotypes. Some of tested lines could be promising source for effective Yr resistance genes such as Yr5, Yr17, Yr18 and Yr26
Effect of certain essential oils and biocides on controlling marjoram root rot and wilt diseases
Get PDFThe aim of this study was to determine the impact of certain essential oils (eucalyptus and thyme essential oils) and biocides (Plant Guard and Rhizo-N) as fungicidal alternatives for the control of root rot and wilt diseases of marjoram (Majorana hortensis L.) caused by several fungi. Marjoram plants with root rot and wilt symptoms were obtained from Giza, Beni-Suief, and Minia governorates, Egypt. Pathogenicity tests showed that all isolated fungi (Fusarium semitectum, F. solani, F. oxysporum, F. roseum, Rhizoctonia solani, and Macrophomina phaseolina) had the ability to infect plants and seedlings. Fusarium oxysporum, followed by R. solani, was the most pathogenic fungus on the marjoram seedlings, resulting in pre- and post-emergence damping-off. Additionally, the most significant disease incidence percentages on marjoram plants after transplanting were caused by F. oxysporum and F. semitectum. In vitro investigations were performed utilizing eucalyptus and thyme essential oils indicated that the growth of the investigated fungi (F. oxysporum, F. semitectum, and R. solani) was significantly inhibited. However, thyme was the most efficient treatment, especially at a concentration of 6000 ppm, which completely inhibited mycelial growth of R. solani and F. oxysporum. The effectiveness of eucalyptus and thyme essential oils, Plant Guard, Rhizo-N, and Actamyl 70% wp was determined for the control of target diseases under greenhouse conditions. The results showed that all tested treatments significantly reduced the disease incidence caused by the investigated fungi. Actamyl was the most efficient treatment. Thyme oil was an effective treatment against R. solani and F. oxysporum in the second order following Actamyl, whereas Plant Guard was effective against F. semitectum and F. oxysporum. Generally, Plant Guard was the most successful treatment for enhancing plant growth of marjoram plants. These findings demonstrate the potential of applying Plant Guard as an alternate fungicide against wilt and root rot diseases of marjoram plants
Detection of Ralstonia solanacearum phylotype II, sequevar 1 in seasonal weed plants associated with potato cultivations in Egypt
Get PDFتم أخذ عينات عشوائية من نباتات الØشائش من Øقول البطاطس المختلÙØ© الموجودة ببعض القرى المصرية ÙˆÙØصها لمعرÙØ© مدى وجود المسبب المرضي Ralstonia solanacearum بها . كان إجمالي عدد العينات (1609 ) عينة على مدار موسمين(2017 /2018 ( Ùˆ (2018/2019( . تضمنت هذه الØشائش Øوالى (50) نوع نباتي تابعين Ù„Øوالي (20) عائلة نباتية، اخذت هذه العينات من Øقول البطاطس الموجودة ببعض القرى التابعة لمØاÙظات القليوبية ،البØيرة ØŒ الجيزة ØŒ الغربية ØŒ الاسماعيلية والمنوÙية (دجوى، السعدنى ØŒ الرÙاعى ØŒ ÙƒÙر يعقوب ØŒ أبوصوير وطاليا) على الترتيب. تم عزل المسبب المرضى من (272) عينه من الØشائش وتضمن هذا العدد Øوالى (25) نوع نباتي تابعين Ù„ (13) عائلة نباتية. تم تجميع هذه الØشائش على عمر 70 يوم من زراعة البطاطس ولم تكن الØشائش بها أي أعراض تدل على اصابتها بالبكتريا المسببة لمرض العÙÙ† البنى ÙÙŠ البطاطس. بصÙØ© عامة كان معدل اصابة هذه الØشائش بالبكتريا المسببة لمرض العÙÙ† البنى قليلا اذ وصل الى Øوالى (16.9%). انتمت جميع عزلات ال R. solanacearum المعزولة من الØشائش الى phylotype II, sequevar 1 (race 3, biovar 3). أوضØت النتائج ان أعلى نسبة إصابة للØشائش بالبكتريا كانت ÙÙŠ Ù…ØاÙظتي الغربية والقليوبية Øيث بلغت (44.7) Ùˆ (31.7%) على الترتيب تلاهم ÙÙŠ الاصابة Ù…ØاÙظة البØيرة Øيث بلغت نسبة الاصابة الى (16,1%) بينما سجلت Ù…ØاÙظة المنوÙية اقل نسبة إصابة (11,5%). علاوة على ذلك Ùقد سجلت كلا من Ù…ØاÙظتي الجيزة والاسماعيلية تقريبا Ù†Ùس نسبة الاصابة ÙÙŠ الØشائش اذ بلغت (12,7Ùˆ13,9% ) على الترتيب. كانت الØشائش الشتوية الØولية هي الأكثر إصابة وتضمنت (11 ) نوعاً
Chenopodium album L., Chenopodium mural L., Cichorium pamilum, Malva parviflora L., Medicago polymorpha L., Rumex dentatus L., Sisymbrium irio L., Sonchus oleraceus L. and Urtica urens L..
تلاهم ÙÙŠ الاصابة الØشائش الصيÙية الØولية والتي شملت (7) انواع من الØشائش المختلÙØ© :
Arachis hypogaea, Conyza aegyptiaca L., Cyperus difformis L., Dactyloctenium aegyptium L, Polypogon monspeliensis L.,Portulaca oleracea L.and Solanum nigrum L.
بينما تضمنت الØشائش المعمرة على (4) أنواع من الØشائش:
Convolvulus arvensis L., Cyperus rotundus L., Cynodon dactylon L., Dichanthium annulatum.
علاوة على ذلك Ùقد اشتملت الØشائش ذات الØولين على (2) Ùقط من الØشائش وهما:
Centaurea calcitrapa L.and Beta vulgaris L
تشير النتائج إلى أن الØشائش الخالية من الأعراض قد تكون مصدرًا خطيرًا للإصابات الكامنة لكلا من الØشائش أو Ù…Øصول البطاطس المعد للتصدير ويمكن اعتبارها من عوائل بكتيريا ال R. solanacearum
Weed plants were randomly sampled from different potato fields in some Egyptian villages and were examined for the presence of Ralstonia solanacearum. A total of (1609) plants were sampled over two year's period (2017/2018 and 2018/2019). These weeds were found belonging to almost (50) species affiliated to (20) families associated more or less with the potato fields near Al-Kalubeiah, El-Behira, El-Giza, El-Gharbeya, El-Ismailia and El-Menofiya governorates at different village (Digwa, El-Saadany, Al-Rifai, Kafr-Yaqoub, Abu Sawyer and Talia, respectively). The pathogen was successfully recovered from the crown area of 272 plant weeds belonging to 25 plant species of 13 families. The weeds in concern, 70 days after planting potato, were found latently infected and mostly symptomless at the time of sampling. The rates of positive isolation from these weeds were generally low, and account for 16.9%. All isolates of R. solanacearum from weeds were confirmed as phylotype II, sequevar 1 (race 3, biovar 2) via PCR. Data revealed that, the highest infection percentage of weed plants were shown from El-Gharbeya and Al-Kalubeiah, governorates (44.7 and 31.7 % respectively) followed by El-Behira governorate (16.1%), whereas the lowest percentage (11.5%) was observed in El-Menofiya governorate. On the other hand, both El-Giza and El-Ismailia governorates showed almost similar percentage of infected weeds (12.7 and 13.9% respectively). The winter annual weeds were the most affected weeds and included 11 different species of weeds (e.g. Amaranthus ascendens Lois, Amaranthus cruentus, Chenopodium album and Chenopodium mural) followed by the summer annual weeds that included 7 different species (e.g. Portulaca oleracea L. and Solanum nigrum L.). While the perennial weeds included 4 species (e.g. Convolvulus arvensis and Dicanthium annulatum), the biennial, however, weeds included only two species of infected weeds (Beta vulgaris L. and Centaurea calcitrapa L.). The results denoting that symptomless weeds might be a serious masked source of latent infection for either weeds or exported potato crop and it may be considered as an attractive overwintering hosts of R. solanacearum