scholarly journals Biologicals and New Generation Fungicides in the Management of Blast Disease in Rice

2021 ◽  
Vol 5 ◽  
Author(s):  
Rajendra Persaud ◽  
Duraisamy Saravanakumar ◽  
Mahendra Persaud ◽  
Govind Seepersad
Keyword(s):  
Field Conditions ◽  
Blast Disease ◽  
Growth And Yield ◽  
Yield Enhancement ◽  
Effective Control ◽  
Thymus Vulgaris ◽  
Syzygium Aromaticum ◽  
Tagetes Patula ◽  
New Generation

Background: Blast is a devastating disease in rice production. The current research tested the efficacy of biologicals and fungicides against blast. Aqueous extracts of Azadirachta indica, Ocimum basalicum, Cymbopogan flexousus, Thymus vulgaris, Aloe vera, Tagetes patula, Cordia curassavica, Aegle marmelos, Allium fistulosum, Syzygium aromaticum, and Calotropis gigantea were tested in vitro at 5, 10, and 15% concentrations against Magnaporthe oryzae. Also, two isolates, Bacillus cereus OG2L and B. subtilis OG2A, and one isolate, Azotobacter SAG19, and, similarly, five new generation fungicides were evaluated at three different doses against blast pathogen M. oryzae in vitro. The treatments that exhibited the best performance in vitro were further evaluated against blast disease under field conditions.Results: Extracts of T. patula (5%), C. gigantea (5%), C. curassavica (10%), A. fistulosum (10%), and A. marmelos (15%) showed greater than 81% inhibition to M. oryzae in vitro. Likewise, all three biocontrol agents, viz. B. cereus OG2L, B. subtilis OG2A, and Azotobacter SAG19, demonstrated more than 50% inhibition of mycelial growth of pathogen in vitro, and the commercial formulations of fungicides Propineb, Trifloxystrobin+Tebuconazole, Tebuconazol+Triadimenol, Bacillus subtilis Strain QST 713, and Cinnamon Oil 8%+Clove Oil 2% also significantly inhibited M. oryzae. Under field conditions, C. curassavica (10%), A. marmelos (15%), C. gigantea (5%); B.cereus OG2L; B.subtilis OG2A; Proineb and Trifloxystrobin+Tebuconazole were effective in reducing disease in addition to yield enhancement.Conclusion: Overall, the plant extracts (C. curassavica at 10%, A. marmelos at 15%, C. gigantea at 5%); bio-agents (B. cereus OG2L, B. subtilis OG2A both at 2g/l), and new generation fungicides Antracol 70WP (Proineb) at 2.5 g/l and Nativo 75 WG (Trifloxystrobin+Tebuconazole) at 0.5 g/l provided effective control against blast disease and superior plant growth and yield compared with other treatments and untreated control.

Combinatorial Synthesis of Novel 1-Sulfonyloxy/acyloxyeugenol Derivatives as Fungicidal Agents

2021 ◽  
Vol 24 ◽  
Author(s):  
Genqiang Chen ◽  
Lina Zhu ◽  
Jiaxuan He ◽  
Song Zhang ◽  
Yuanhao Li ◽  
...  
Keyword(s):  
Fungicidal Activity ◽  
High Efficiency ◽  
Biological Activities ◽  
Phytophthora Capsici ◽  
Effective Control ◽  
Syzygium Aromaticum ◽  
Wide Range ◽  
Structural Skeleton ◽  
Acyloxy Group

Background: Developing the high-efficiency and low-risk small-molecule green-fungicide is the key to effective control of the plant pathogenic oomycetes. Essential oils play a very important role in novel fungicide discovery for their unique sources and potential target sites. Eugenol, a kind of plant essential oil, was mainly isolated from the unopened and dried flower buds of Syzygium aromaticum of the Myrtaceae family. Due to its unique structural skeleton, eugenol and its derivatives have exhibited a wide range of biological activities. However, study on the synthesis of novel 1-sulfonyloxy/acyloxyeugenol derivatives as fungicidal agents against Phytophthora capsici has not yet been reported. Methods: Twenty-six novel 1-sulfonyloxy/acyloxyeugenol derivatives (3a-p and 5a-j) were prepared and their structures were well characterized by 1H NMR, HRMS, and m.p.. Their fungicidal activity was evaluated against P. capsici by using the mycelial growth rate method. Results: To find novel natural-product-based fungicidal agents to control the plant pathogenic oomycetes, we herein designed and synthesized two series of novel 1-sulfonyloxy/acyloxyeugenol derivatives (3a-p and 5a-j) as fungicidal agents against P. capsici Leonian, in vitro. Results of fungicidal activity revealed that, among all compounds, especially compounds 3a, 3f, and 3n displayed the most potent anti-oomycete activity against P. capsici with EC50 values of 79.05, 75.05, and 70.80, respectively. Conclusion: The results revealed that the anti-oomycete activity of eugenol with the sulfonyloxy group was higher than that with the acyloxy group. It is suggested that the fungicidal activity of eugenol can be improved by introducing the sulfonyloxy group. This will pave the way for further design, structural modification, and to develop eugenol derivatives as fungicidal agents.

Phaseolus acutifolius ASSOCIATED WITH Bacillus amyloliquefaciens AND Azospirillum halopraeferens UNDER SALINITY CONDITIONS

Biotecnia ◽  
2019 ◽  
Vol 21 (1) ◽  
pp. 127-132
Author(s):  
R. Prabhaharan ◽  
J. Borboa-Flores ◽  
E. C. Rosas-Burgos ◽  
J. L. Cárdenas-López ◽  
J. Ortega-García ◽  
...  
Keyword(s):  
Bacillus Amyloliquefaciens ◽  
Field Conditions ◽  
Growth And Yield ◽  
Yield Enhancement ◽  
Arid Zones ◽  
Potential Yield ◽  
Phaseolus Acutifolius ◽  
Plant Parts ◽  
Mexican State ◽  
Plant Growth Promoting

Salinity-tolerant plants offer hope for the future of agriculture by providing solutions to the problems caused by years. Sonora is the most arid Mexican state. The agroindustrial halophytes are an option in dry-arid zones agriculture. In the present study, we evaluated the growth and development under different salinity and field conditions, of two beans (Phaseolus acutifolius) genotypes: Indio Yumi, and Navojoa. Seeds were inoculated with plant growth promoting halobacteria, a previously selected and cultivated strain of Azospirillum halopraeferens and a native Bacillus amyloliquefaciens. Significant differences were observed among them for weight and biomass, as well as biochemical features between the analyzed plant parts. Our findings suggest that a potential yield enhancement and protein production under field conditions can be promoted by the application of the beneficial bacterium B. amyloliquefaciens and A. halopraeferens. Also, demonstrated the ability of the studied beneficial halobacteria to promote growth and yield of the halotolerant Phaseolus acutifolius, a potentially useful finding for the agricultural growers in dry and semiarid zones.

scholarly journals Efficacy of Bacterial Seed Treatments for Controlling Pythium Root Rot of Winter Wheat

Plant Disease ◽  
1997 ◽  
Vol 81 (2) ◽  
pp. 180-184 ◽  
Author(s):  
E. A. Milus ◽  
C. S. Rothrock
Keyword(s):  
Root Rot ◽  
Burkholderia Cepacia ◽  
Field Conditions ◽  
Yield Enhancement ◽  
Bacterial Strains ◽  
Seed Treatments ◽  
Wheat Roots ◽  
Commercial Use ◽  
Pythium Root Rot

Pythium root rot, caused by various Pythium spp., is a widespread disease of wheat. The objective of this study was to identify bacterial strains from wheat roots in Arkansas that suppressed Pythium root rot and to compare their efficacy with that of bacterial strains from other areas. Bacterial strains (applied as seed treatments) that suppressed Pythium root rot in growth chamber assays were evaluated further for in vitro antibiosis against three Pythium spp. and for efficacy under field conditions. Pseudomonas fluorescens strain 2-79R, Burkholderia cepacia strain 1-23, and Pseudomonas sp. strain 1-30 were the most effective for suppressing Pythium root rot under field conditions and significantly (P = 0.10) increased yield in one experiment. Strains that were effective in the field also expressed in vitro antibiosis to at least two of three Pythium spp.; however, strains expressing the highest levels of antibiosis were not effective in the field. In the field, root rot suppression and yield enhancement were inconsistent across experiments and generally small in magnitude. Therefore, these strains have little potential for commercial use under the conditions in which they were tested.

scholarly journals Evaluation in vitro du potentiel antagoniste de Trichoderma harzianum du Burkina Faso contre Magnaporthe grisea, l’agent causal de la pyriculariose du riz, isolées au Mali

2020 ◽  
Vol 13 (7) ◽  
pp. 3053-3065
Author(s):  
Yaya Kone ◽  
Tobdem Gaston Dabire ◽  
Hamadoun Amadou ◽  
Irénée Somda
Keyword(s):  
Burkina Faso ◽  
Trichoderma Harzianum ◽  
Magnaporthe Grisea ◽  
Genetic Resistance ◽  
Blast Disease ◽  
Effective Control ◽  
Variétés Résistantes ◽  
Antagonistic Potential ◽  
Risques Sanitaires

Magnaporthe grisea, pathogène du riz est cosmopolite et cause d’énormes dégâts au Mali. L’utilisation de variétés résistantes et de fongicides chimiques sont efficaces pour son contrôle, mais présentent des limites objectives avec le contournement des gènes de résistances par l’agent pathogène, ainsi que les risques sanitaires et environnementaux que présentent les fongicides. Avec cette information de base, cette étude s’est proposée de développer une stratégie de lutte biologique utilisant des antagonismes naturels afin de contrôler M. grisea. Dix souches de M. grisea du Mali ont été caractérisées morphologiquement et moléculairement pour confirmer leurs identité et variabilité. L’action antagoniste in vitro de 05 souches de T. harzianum a été évaluée sur ces souches pathogènes. M. grisea et T. harzianum ont ainsi été mises en confrontation directe dans des boites de Petri pendant 06 jours. Les croissances radiales du pathogène ont été évaluées et les coefficients d’antagonisme calculés. L’analyse moléculaire a indiqué que toutes les souches appartiennent à M. grisea et présentent de fortes homologies avec les souches de références du NCBI. L’analyse des séquences a indiqué trois groupes légèrement distingués. Toutes les souches de T. harzianum ont inhibé la croissance du pathogène avec des coefficients d’antagonisme compris entre 0,50 et 0,78.Mots clés: Riz, Magnaporthe grisea, In vitro, Trichoderma harzianum, antagonisme. English Title: In vitro evaluation of the antagonistic potential of Trichoderma harzianum from Burkina Faso against Magnaporthe grisea, the causative agent of rice blast disease, isolated in MaliMagnaporthe grisea, a rice pathogen, is cosmopolitan and causes enormous damage in Mali. The use of resistance cultivars and chemical fungicide are generally effective control methods. However, the durability of genetic resistance is often short-lived because of the pathogen’s ability to rapidly evolve to overcome resistance gene, and then environmental and toxicity threat of chemicals employment. With this basic information, this study proposed to develop an alternative strategy to control M. grisea with T. harzianum. M. grisea from Mali has been characterized morphologically and molecularly to confirm their identity and variability. The in vitro antagonistic action of 05 strains of T. harzianum was tested. M. grisea and T. harzianum were thus confronted with a direct confrontation in the Petri dishes during 06 days. The radial growths of the pathogen were evaluated and the coefficients of antagonism calculated. Molecular analysis with all strains corresponds to M. grisea and strong assertions with NCBI reference strains. Sequence analysis indicated three slightly distinguished groups. T. harzianum strains inhibited growth of the pathogen with antagonistic coefficients between 0.50 and 0.78.Keywords: Rice, Magnaporthe grisea, In vitro, Trichoderma harzianum, antagonism

scholarly journals Antimicrobial Essential Oil Formulation: Chitosan Coated Nanoemulsions for Nose to Brain Delivery

Pharmaceutics ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 678 ◽  
Author(s):  
Federica Rinaldi ◽  
Alessandra Oliva ◽  
Manuela Sabatino ◽  
Anna Imbriano ◽  
Patrizia N. Hanieh ◽  
...  
Keyword(s):  
Thymus Vulgaris ◽  
Syzygium Aromaticum ◽  
Drug Resistant ◽  
Bacterial Strains ◽  
Onset Of Action ◽  
Gram Negative ◽  
Efficient Delivery ◽  
Oil Formulation ◽  
The Brain

Brain infections as meningitis and encephalitis are attracting a great interest. Challenges in the treatment of these diseases are mainly represented by the blood brain barrier (BBB) that impairs the efficient delivery of even very potent drugs to reach the brain. The nose to the brain administration route, is a non-invasive alternative for a quick onset of action, and enables the transport of numerous medicinal agents straight to the brain thus workarounding the BBB through the highly vascularized olfactory region. In this report, Thymus vulgaris and Syzygium aromaticum essential oils (EOs) were selected to be included in chitosan coated nanoemulsions (NEs). The EOs were firstly analyzed to determine their chemical composition, then used to prepare NEs, that were deeply characterized in order to evaluate their use in intranasal administration. An in vitro evaluation against a collection of clinical isolated bacterial strains was carried out for both free and nanoemulsioned EOs. Chitosan coated NEs showed to be a potential and effective intranasal formulation against multi-drug resistant Gram-negative bacteria such as methicillin-susceptible Staphylococcus aureus and multi-drug resistant Gram-negative microorganisms including carbapenem-resistant Acinetobacter baumannii and Klebsiella pneumoniae.

scholarly journals Essential oils in the control of dry bubble disease in white button mushroom

2017 ◽  
Vol 47 (5) ◽  
Author(s):  
Tamara Leite dos Santos ◽  
Leônidas Leoni Belan ◽  
Diego Cunha Zied ◽  
Eustáquio Souza Dias ◽  
Eduardo Alves
Keyword(s):  
Essential Oils ◽  
Thymus Vulgaris ◽  
Good Growth ◽  
Syzygium Aromaticum ◽  
Cinnamon Oil ◽  
In Vivo Experiments ◽  
Dry Bubble ◽  
Dry Bubble Disease

ABSTRACT: Lecanicillium fungicola, which causes Dry bubble disease, induces infections and inflicts major losses in champignon production. The control can be managed through measures of hygiene and use of fungicides; however, in Brazil there are no registered products. This study aimed to estimate the influence of various essential oils extracted from Melissa officinalis, Thymus vulgaris, Origanum vulgare, Eucalyptus globulus, Cinnamomum zeylanicum and Syzygium aromaticum on the in vitro development and their uses. Therefore, analysis was performed of the L. fungicola isolates in vitro and the best oils were tested in vivo. Besides, the Agaricus bisporus - L. fungicola interaction was confirmed by scanning electron microscopy (SEM). Cinnamon and clove oils in concentrations of 0.4% and thyme oil of 0.8% were identified as good growth inhibitors of the pathogenic mycelium. Effective inhibition of the conidial germination was seen in all concentrations by cinnamon oil, and by clove and thyme oils only at 0.4% and 0.8%, respectively. When the essential oils were applied post-infestation in the in vivo experiments the incidence of the disease in the mushrooms was much lower. From the SEM it was clear that 19 hours after the inoculation of A. bisporus with L. fungicola, the spores had already completely germinated, revealing the presence of the infection. Therefore, the findings of this study indicated that the oil extracts of cinnamon, clove and thyme are potential and efficient alternatives in the control of dry bubble disease.

scholarly journals Investigation of Effects of Ecological Factors on the Establishment of Azotobacter in the Rhizosphere of Thyme (Thymus vulgaris)

2020 ◽  
pp. 22-27
Author(s):  
Nathaniel N. Ngerebara ◽  
Lawrence O. Amadi
Keyword(s):  
Ecological Factors ◽  
Botanical Garden ◽  
Growth And Yield ◽  
Thymus Vulgaris ◽  
Phosphate Solubilizing Bacteria ◽  
Rhizospheric Bacteria ◽  
Significant Difference ◽  
Phosphate Solubilizing ◽  
The Impact

Aim: The present study investigates the effect of phosphate-solubilizing bacteria (phosphobacteria (PB) and activity of soil bacteriostasis on the development of Azotobacter in Thymus vulgaris rhizosphere. Place and Duration of Study: The study was conducted at Kenule Beeson Polytechnic botanical garden and at the Science Laboratory Department of the institution for a period of 7months (from March 2018- September 2018).  Methods: The impact of phytohormones produced by phosphate-solubilizing bacteria in vitro and in the rhizosphere of T. vulgaris was used to assay for Azotobacter colonization. Bacteriostasis activity of the soil was determined by comparing the number of Azotobacter microcolonies on discs incubated over soil with respect to those on the controls. Results: Decisive stimulation of Azotobacter population and establishment was observed in Thymus vulgaris rhizosphere when inoculated with phosphobacteria than when inoculated alone as reflected in 5% (0.05) least significant difference. Azotobacter was susceptible to the bacteriostatic factors in potted soils inoculated with it and without (Azotobacter). The increase in susceptibility of this rhizospheric bacteria was time dependent and reached a maximum and thereafter remained almost constant. However, this was overcome by the addition of NPK fertilizer to the plant at some critical stage of the assay. Conclusion: The Presence of nitrogen fixing bacteria (NFB) in vegetation could play significant role in the sustainability and improvement of plant growth and yield. Soil bacteriostasis can also be an important factor that limits the survival and development of NFB.

scholarly journals In Vitro Activity of Essential Oils against Saprolegnia parasitica

Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1270 ◽  
Author(s):  
Simona Nardoni ◽  
Basma Najar ◽  
Baldassare Fronte ◽  
Luisa Pistelli ◽  
Francesca Mancianti
Keyword(s):  
Essential Oils ◽  
Present Report ◽  
Thymus Vulgaris ◽  
Citrus Limon ◽  
Syzygium Aromaticum ◽  
Citrus Paradisi ◽  
Fish Farms ◽  
Foeniculum Vulgare ◽  
Saprolegnia Parasitica

Saprolegnia spp. water molds severely impact fish health in aquaculture, fish farms and hobby fish tanks colonizing mature and immature stages of fishes, as well as eggs. Considering that there are no drugs licensed for treating and/or control the organism, efficient and environmental low-impact methods to control these oomycetes in aquaculture are needed. The aim of the present report was to evaluate the in vitro sensitivity of Saprolegnia parasitica to essential oils (EOs) from Citrus aurantium L., Citrus bergamia Risso et Poiteau, Citrus limon Burm. f., Citrus paradisi Macfad, Citrus sinensis Osbeck, Cinnamomum zeylanicum Blume, Cymbopogon flexuosum (Nees ex Steud.) Watson, Foeniculum vulgare Mill., Illicium verum Hook.f., Litsea cubeba (Lour.) Pers., Origanum majorana L., Origanum vulgare L., Pelargonium graveolens L’Hér., Syzygium aromaticum Merr. & L.M.Perry, and Thymus vulgaris L., by microdilution test. The most effective EOs assayed were T. vulgaris and O. vulgare, followed by C. flexuosum, L. cubeba and C. bergamia. These EOs could be of interest for controlling Saprolegnia infections. Nevertheless, further safety studies are necessary to evaluate if these products could be dispersed in tank waters, or if their use should be limited to aquaculture supplies.

scholarly journals Effect of Bio-Control Agents on Yield, Yield Components and Root Rot Control in two Wheat Cultivars at New Valley Region

2011 ◽  
Vol 3 (4) ◽  
pp. 79-87 ◽  
Author(s):  
Mohamed Yosseif MOUBARK ◽  
Montaser Fawzy ABDEL-MONAIM
Keyword(s):  
Grain Yield ◽  
Root Rot ◽  
Trichoderma Viride ◽  
Pathogenic Fungi ◽  
Kernel Weight ◽  
Field Conditions ◽  
Growth And Yield ◽  
Wheat Cultivars ◽  
Application Methods

This study evaluated the effectiveness of applying the bioagents Bacillus subtilis (isolate BSM1), B. megaterium (isolate BMM5), Trichoderma viride (isolate TVM2) and T. harzianum (isolate THM4) for the control of rot root disease caused by Fusarium graminearum, Drechslera halodes and Rhizoctonia solani on two wheat cultivars ('Sakha 93' and 'Bani Suif 5') under greenhouse conditions. Moreover, their effect wheat growth and yield were also studied under field conditions. In vitro, all tested bioagents were significantly in the reduced redial growth of the pathogenic fungi. Trichoderma viride was active more than the other tested bioagents followed by T. harzianum, while B. subtilis was the least ones. Under greenhouse conditions, all tested bioagents were able to reduce significantly damping-off and root rot caused by the tested pathogens compared with control and increased fresh and dry weight of the survival plants when applied as soil or grain treatments however, there was variation among bioagent isolates effect on reduction of disease severity both application methods. Trichoderma viride and B. megaterium were recorded the highest effective in this respect compared with other tested bioagents. Under field conditions, analysis of variance and mean performance were estimated for four characters: grain yield 4.8 m-2, No. of spikes m-2, No. of kernels spike-1 and 1,000-kernel weight. Significant mean squares were obtained for all studied characters between the seasons (S), methods (M), (S) (M), treatments (T), (S) (T), (M) (T) and (S) (M) (T) for 'Sakha 93' cultivar and 'Bani Suif 5' cultivar except application methods and (S) (M) for number of kernels spike-1 and 1,000-kernel weight, respectively. While the treatments T. harzianum and B. megaterium were the best treatments to increase grain yield, the treatments B. subtilis and T. harzianum were best treatments to increase number of spikes and the treatments B. subtilis and B. megaterium were best treatments to increase number of kernels for soil and grain application methods, respectively.

scholarly journals Composição química e concentração mínima bactericida de dezesseis óleos essenciais sobre Escherichia coli enterotoxigênica

2016 ◽  
Vol 18 (1) ◽  
pp. 105-112 ◽  
Author(s):  
A.A. SOUZA ◽  
N.A.A. DIAS ◽  
R.H. PICCOLI ◽  
S.K.V. BERTOLUCCI
Keyword(s):  
Escherichia Coli ◽  
Thymus Vulgaris ◽  
Syzygium Aromaticum ◽  
Cymbopogon Citratus ◽  
Origanum Vulgare ◽  
Cinnamomum Cassia

RESUMO Este trabalho teve por objetivo avaliar o efeito bactericida in vitro de dezesseis óleos essenciais sobre Escherichia coli enterotoxigênica (ETEC). Dentre os óleos essenciais estudados, três foram extraídos in situ por arraste a vapor e treze foram adquiridos comercialmente. Todos os óleos foram analisados por CG-EM e CG-DIC. A atividade bactericida foi avaliada pelo método de microdiluição utilizando-se caldo triptona de soja e microplacas de poliestireno de 96 poços, com posterior plaqueamento das culturas em ágar triptona de soja. Os óleos essenciais de Cinnamomum cassia e de Thymus vulgaris apresentaram concentração mínima bactericida (CMB) de 0,12% e 0,25%, respectivamente. Já os óleos comerciais de Syzygium aromaticum e Origanum vulgare apresentaram ambos CMB de 0,50% e os óleos extraídos in situ de Cymbopogon citratus e Origanum vulgare apresentaram ambos CMB de 1,00%. Os dezesseis óleos essenciais apresentaram composição química qualitativa e quantitativa distintas. As análises químicas dos óleos essenciais de Cinnamomum cassia e de Thymus vulgaris tiveram a presença majoritária de E-cinamaldeído (84,52%) e timol (50,89%). Conclui-se que os óleos de C. cassia e T. vulgaris foram os mais eficazes na inibição do crescimento in vitro dessa bactéria, a qual possui diferentes níveis de sensibilidade dependendo da composição química do óleo.

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