scholarly journals Optimization of the Extraction Process and Application of Bacterial Extracts in the Control of Brown Spot and Leaf Blast in Rice Culture

2021 ◽  
Author(s):  
Marina Teixeira Arriel-Elias ◽  
Gabriel Carlos Teixeira Freire Arriel ◽  
Gustavo Andrade Bezerra ◽  
Pedro Henrique Dias dos Santos ◽  
Vanessa Gisele Pasqualotto Severino ◽  
...  
Keyword(s):  
Serratia Marcescens ◽  
Leaf Area ◽  
Colony Growth ◽  
Extraction Process ◽  
Brown Spot ◽  
Bacillus Sp ◽  
Bipolaris Oryzae ◽  
Leaf Blast ◽  
Rice Culture ◽  
Three Stages

Abstract The objective of this work was to optimize the extraction process and application of bacterial extracts of Bacillus sp. and Serratia sp. in leaf blast control (Magnapothe oryzae) and brown spot (Bipolaris oryzae) in rice culture. The work was divided into three stages: 1) Bacterial obtaining extracts through liquid-liquid extraction 2) Antagonistic capacity of bacterial extracts to M. oryaze and B. oryae 3) Suppression of brown spot (A1) and leaf blast (A2) in greenhouse. The bacterial isolates in present study were identified as Bacillus sp. (BRM32110) and Serratia marcescens (BRM32113). The crude extract of both isolates at different extraction times 6, 16, 24, 48 and 72 hours reduced the growth of colonies of M. oryzae and B. oryzae by up to 92% and 28%, respectively. The extracts that showed highest inhibition of colony growth were those obtained after 6 and 16h of incubation and were selected for subsequent assays. These, for both isolates were able to reduce conidia germination by up to 91% and apressorium formation of M. oryzae by up to 93%. In green house, A1 the treatment that stood out was the extract of Bacillus sp. (16h) with 6.7% of leaf area affected and in A2 the treatment S. marcescens extract (16h) stood out with only 7.6% of leaf area affected with brusone when compared to control. The use of extracts of Bacillus sp. and Serratia marcescens was efficient in reducing the severity of brown spot and leaf blast in rice crop.

Studies on the behaviour of some fungal diseases of rice in the mangrove swamp ecology at Warri, south eastern Nigeria

2003 ◽  
Vol 51 (4) ◽  
pp. 429-436
Author(s):  
E. A. Maji ◽  
E. D: Imolehin
Keyword(s):  
Disease Incidence ◽  
Block Design ◽  
Rice Variety ◽  
N Fertilization ◽  
Brown Spot ◽  
Bipolaris Oryzae ◽  
Southeastern Nigeria ◽  
Mangrove Swamp ◽  
Main Plot ◽  
Cropping Seasons

Studies on the ecological behaviour of Cochliobolus miyabeanus (Ito et Kurib.) Drechsl. ex Dast., syn. Bipolaris oryzae (Breda de Haan Shoem.), the causal agent of brown spot in rice (Oryza sativa L.), were carried out in the tidal mangrove swamp at Warri Experimental Farm, Southeastern Nigeria. A split randomised complete block design with four replications was used. Monthly transplantings from July to September formed the main plot, which was subdivided into control and N-treated subplots. Disease incidence increased when transplanting was delayed. This was probably due to the fact that flowering coincided with environmental conditions favourable for disease development from November to February. Nitrogen fertilization at 40 kg N/ha significantly (P=0.05) reduced C. miyabeanus incidence in 1997/1998, but not in the 1998/1999 and 1999/2000 cropping seasons at the same site. The grain yields of ROK 5, a medium-duration improved rice variety (approx. 150 days), were significantly (P=0.05) reduced in late-transplanted crops (September to November) in spite of adequate N fertilization. Mangrove mud was not an important source of C. miyabeanus propagules. The incidence of leaf scald caused by Monographella albescens (Thum) Parkinson, Sivanesan and Booth syn. Microdochium oryzae (Hashioka and Yokogi) Samuels and Hallet, and of leaf smut caused by Etyloma oryzae Miyake was generally stimulated by N application.

scholarly journals Sensitivity of Bipolaris oryzae Isolates Pathogenic on Cultivated Wild Rice to the Quinone Outside Inhibitor Azoxystrobin

Plant Disease ◽  
2019 ◽  
Vol 103 (8) ◽  
pp. 1910-1917 ◽  
Author(s):  
Claudia V. Castell-Miller ◽  
Deborah A. Samac
Keyword(s):  
Cytochrome B ◽  
Fungicide Resistance ◽  
Wild Rice ◽  
Brown Spot ◽  
Bipolaris Oryzae ◽  
Qoi Fungicides ◽  
Quinone Outside Inhibitor ◽  
Group I ◽  
Mitochondrial Cytochrome B

The occurrence of fungal brown spot, caused by Bipolaris oryzae, has increased in cultivated wild rice (Zizania palustris) paddies in spite of the use of azoxystrobin-based fungicides. The active ingredient blocks electron transfer at the quinone outside inhibitor (QoI) site in the mitochondrial cytochrome b within the bc1 complex, thus obstructing respiration. The in vitro averaged EC50 of baseline isolates collected in 2007 before widespread fungicide use was estimated to be 0.394 µg/ml with PROBIT and 0.427 µg/ml with linear regression analyses. Isolates collected during 2008, 2015, and 2016 had a range of sensitivity as measured by relative spore germination (RG) at a discriminatory dose of 0.4 µg/ml azoxystrobin. Isolates with a higher (≥80%) and lower RG (≤40%) had the wild type nucleotides at amino acid positions F129, G137, and G143 of cytochrome b, sites known to be associated with QoI fungicide resistance. Two Group I introns were found in the QoI target area. The splicing site for the second intron was found immediately after the codon for G143. A mutation for fungicide resistance at this location would hinder splicing and severely reduce fitness. B. oryzae expresses an alternative oxidase in vitro, which allows the fungus to survive inhibition of respiration by azoxystrobin. This research indicates that B. oryzae has not developed resistance to QoI fungicides, although monitoring for changes in sensitivity should be continued. Judicious use of QoI fungicides within an integrated disease management system will promote an effective and environmentally sound control of the pathogen in wild rice paddies.

scholarly journals Research Priorities for Rice Pest Management in Tropical Asia: A Simulation Analysis of Yield Losses and Management Efficiencies

2004 ◽  
Vol 94 (7) ◽  
pp. 672-682 ◽  
Author(s):  
Laetitia Willocquet ◽  
Francisco A. Elazegui ◽  
Nancy Castilla ◽  
Luzviminda Fernandez ◽  
Kenneth S. Fischer ◽  
...  
Keyword(s):  
Pest Management ◽  
Management Strategies ◽  
Research Priorities ◽  
Sheath Blight ◽  
Brown Spot ◽  
Yield Losses ◽  
Leaf Blast ◽  
Tropical Asia ◽  
Neck Blast ◽  
Rice Pest

A simulation study was conducted to assess the current and prospective efficiency of rice pest management and develop research priorities for lowland production situations in tropical Asia. Simulation modeling with the RICEPEST model provided the flexibility required to address varying production situations and diverse pest profiles (bacterial leaf blight, sheath blight, brown spot, leaf blast, neck blast, sheath rot, white heads, dead hearts, brown plant-hoppers, insect defoliators, and weeds). Operational definitions for management efficacy (injury reduction) and management efficiency (yield gain) were developed. This approach enabled the modeling of scenarios pertaining to different pest management strategies within the agroecological contexts of rice production and their associated pest injuries. Rice pests could be classified into two broad research priority-setting categories with respect to simulated yield losses and management efficiencies. One group, including weeds, sheath blight, and brown spot, consists of pests for which effective pest management tools need to be developed. The second group consists of leaf blast, neck blast, bacterial leaf blight, and brown plant-hoppers, for which the efficiency of current management methods is to be maintained. Simulated yield losses in future production situations indicated that a new type of rice plant with high-harvest index and high-biomass production (“New Plant Type”) was more vulnerable to pests than hybrid rice. Simulations also indicated that the impact of deployment of host resistance (e.g., through genetic engineering) was much larger when targeted against sheath blight than when targeted against stem borers. Simulated yield losses for combinations of production situations and injury profiles that dominate current lowland rice production in tropical Asia ranged from 140 to 230 g m-2. For these combinations, the simulated efficiency of current pest management methods, expressed in terms of relative yield gains, ranged from 0.38 to 0.74. Overall, the analyses indicated that 120 to 200 × 106 tons of grain yield are lost yearly to pests over the 87 × 106 ha of lowland rice in tropical Asia. This also amounts to the potential gain that future pest management strategies could achieve, if deployed.

scholarly journals Confirming a major QTL and finding additional loci responsible for field resistance to brown spot (Bipolaris oryzae) in rice

2015 ◽  
Vol 65 (2) ◽  
pp. 170-175 ◽  
Author(s):  
Hiroyuki Sato ◽  
Kengo Matsumoto ◽  
Chihiro Ota ◽  
Tomohiro Yamakawa ◽  
Junichi Kihara ◽  
...  
Keyword(s):  
Field Resistance ◽  
Brown Spot ◽  
Bipolaris Oryzae ◽  
Major Qtl

scholarly journals Efficacy of Pre- and Postinoculation Application of Fungicides to Expanding Young Citrus Leaves for Control of Melanose, Scab, and Alternaria Brown Spot

Plant Disease ◽  
2007 ◽  
Vol 91 (12) ◽  
pp. 1600-1606 ◽  
Author(s):  
S. N. Mondal ◽  
A. Vicent ◽  
R. F. Reis ◽  
L. W. Timmer
Keyword(s):  
Disease Control ◽  
Leaf Area ◽  
Quadratic Equation ◽  
Brown Spot ◽  
Copper Hydroxide ◽  
Fungicide Application ◽  
Potted Plants ◽  
Rough Lemon ◽  
Alternaria Brown Spot ◽  
Young Leaves

In greenhouse trials, copper hydroxide, pyraclostrobin, and famoxadone were applied to actively growing young citrus seedlings to determine the duration of protection of young leaves provided by these fungicides against melanose, caused by Diaporthe citri, citrus scab, caused by Elsinoe fawcettii, and Alternaria brown spot, caused by Alternaria alternata. Fungicides were applied to different sets of potted plants of grapefruit for control of melanose, of rough lemon for control of scab, and of Dancy tangerine for control of Alternaria brown spot 1 to 6 days prior to inoculation, as well as on the day of inoculation. Leaf area of treated shoots was estimated on the day of fungicide application and the day of inoculation and disease severity evaluated subsequently. In most cases, copper hydroxide and famoxadone provided at least 50% control of all three diseases for only about 2 days after application. Generally, there was little or no disease control when the products were applied 4 or more days before inoculation. In contrast, pyraclostrobin usually provided a high level of control of all three diseases when applied up to 5 days prior to inoculation. The level of disease control decreased as the interval between a fungicide application and inoculation increased and the relationship between disease control and leaf expansion best fit a quadratic equation. Effective disease control was observed with copper hydroxide and famoxadone until leaf area had increased by 100 to 200%, whereas control with pyraclostrobin was observed up to 400 to 500% increase in leaf area. In postinoculation tests with scab and melanose, pyraclostrobin provided high levels of disease control (>75%) when applied up to 2 days after inoculation, whereas copper hydroxide and famoxadone had minimal postinoculation activity. Applications of pyraclostrobin to the spring flush growth of citrus trees are much more likely to provide control of melanose, scab, and Alternaria brown spot than those of famoxadone or copper hydroxide.

scholarly journals Disease-Reducing Effect of Chromolaena odorata Extract on Sheath Blight and Other Rice Diseases

2011 ◽  
Vol 101 (2) ◽  
pp. 231-240 ◽  
Author(s):  
Nguyễn Đắc Khoa ◽  
Phan Thị Hồng Thúy ◽  
Trần Thị Thu Thủy ◽  
David B. Collinge ◽  
Hans Jørgen Lyngs Jørgensen
Keyword(s):  
Production Systems ◽  
Foliar Spray ◽  
Rice Cultivar ◽  
Growth Conditions ◽  
Sheath Blight ◽  
Field Conditions ◽  
Brown Spot ◽  
Chromolaena Odorata ◽  
Bipolaris Oryzae ◽  
Herbal Plants

Sheath blight caused by Rhizoctonia solani (teleomorph: Thanatephorus cucumeris) is a major cause of crop loss in intensive rice production systems. No economically viable control methods have been developed. We screened aqueous extracts of common herbal plants that could reduce sheath blight lesions and found that foliar spraying and seed soaking application of extracts of either fresh or dried leaves of Chromolaena odorata gave up to 68% reduction in sheath blight lesion lengths under controlled and semi-field conditions. The observed reductions were not dependent on growth conditions of C. odorata and rice cultivar. The effect was observed until 21 days after inoculation and was not dependent on microbial activity. Under semi-field conditions, extracts also reduced severity of other important rice diseases, i.e., blast (Pyricularia oryzae) using foliar spray (up to 45%), brown spot (Bipolaris oryzae) using seed treatment (up to 57%), and bacterial blight (Xanthomonas oryzae pv. oryzae) using both application methods (up to 50%).

scholarly journals Spatiotemporal Survey of Multiple Rice Diseases in Irrigated Areas Compared to Rainfed Lowlands in the Western Burkina Faso

Plant Disease ◽  
2021 ◽  
Author(s):  
Mariam Barro ◽  
Abalo Itolou Kassankogno ◽  
Issa Wonni ◽  
Drissa SEREME ◽  
Irénée SOMDA ◽  
...  
Keyword(s):  
Burkina Faso ◽  
Fungal Pathogens ◽  
Management Practices ◽  
Brown Spot ◽  
Leaf Blast ◽  
Rice Leaf ◽  
Yellow Mottle ◽  
Rice Leaf Blast ◽  
Study Sites ◽  
Western Burkina Faso

Multiple constraints affect rice yields and global production in West Africa. Among these constraints are viral, bacterial and fungal pathogens. We aimed to describe the spatiotemporal patterns of occurrence and incidence of multiple rice diseases in farmers’ fields in contrasting rice growing systems in western Burkina Faso. For this purpose, we selected a set of three pairs of sites, each comprising an irrigated area and a neighboring rainfed lowland, and studied them over four consecutive years. We first performed interviews with the rice farmers to better characterize the management practices at the different sites. This study revealed that the transplanting of rice and the possibility of growing rice twice a year are restricted to irrigated areas, while other practices, such as the use of registered rice cultivars, fertilization and pesticides, are not specific but differ between the two rice growing systems. Then, we performed symptom observations at these study sites to monitor the following four diseases: yellow mottle disease, Bacterial Leaf Streak (BLS), rice leaf blast and brown spot. The infection rates were found to be higher in irrigated areas than in rainfed lowlands, both when analyzing all observed symptoms together (any of the four diseases) and when specifically considering each of the two diseases: BLS and rice leaf blast. Brown spot was particularly prevalent in all six study sites, while yellow mottle disease was particularly structured geographically. Various diseases were frequently found together in the same field (co-occurrence) or even on the same plant (coinfection), especially in irrigated areas.

scholarly journals Chemical control of rice brown spot (Bipolaris oryzae) in Paraguay

2019 ◽  
Vol 6 (1) ◽  
pp. 148-151
Author(s):  
Marcelo Barúa ◽  
◽  
Lidia Quintana ◽  
Aldo Ortiz ◽  
◽  
...  
Keyword(s):  
Chemical Control ◽  
Brown Spot ◽  
Bipolaris Oryzae

scholarly journals Assessment of Seed Infestation Level of Brown Spot (Bipolaris Oryzae) in Different Rice Genotypes under Natural Epiphytotic Conditions

2016 ◽  
Vol 4 (3) ◽  
pp. 294-297
Author(s):  
Prakash Pantha ◽  
Dil Raj Yadav
Keyword(s):  
Rhizopus Oryzae ◽  
Brown Spot ◽  
Rice Seed ◽  
Infestation Level ◽  
Infection Level ◽  
Bipolaris Oryzae ◽  
Ustilaginoidea Virens ◽  
Disease Occurrence ◽  
Alternaria Sp ◽  
Rice Genotypes

Bipolaris oryzae, the causal agent of brown spot disease, is an economically important pathogen of rice found in several rice growing countries in the world. Seed samples were collected from the rice experimental field comprised of different rice genotypes at National Rice Research Program, Hardinath, Dhanusha, Nepal in 2014 to determine the infestation level of B. oryzae and taxonomic identification of seed borne fungi by standard blotter method. The major recovered fungal mycoflora were B. oryzae, Pyricularia oryzae, Ustilaginoidea virens, Aspergillus flavus, Aspergillus niger, Curvularia oryzae, Rhizopus oryzae, Alternaria sp., Cercospora sp. and Penicillium sp. Seeds of all rice genotypes were infected with these fungi however frequency of fungal association varied among rice genotypes (from 12% to 96%). The percentage infection of B. oryzae was recorded maximum in all the rice genotypes compared to other seed-borne fungi. Madhaya dhan 845 and BI-0530-5-10-1-2 were the most infected genotypes and the infection percentage was 72% and 68%, respectively. Similarly, the least infected genotypes were Sabitri and TN-1 and infection level of 8% was recorded in both genotypes. Our findings may be used to predict disease occurrence and fungal transfer to new uninfected areas. Moreover, this study suggests that rice seed should be properly detected to check contamination by pathogens before sowing for effective and healthy crop production.Int J Appl Sci Biotechnol, Vol 4(3): 294-297

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