Journal articles on the topic 'Disease suppression; Rhizoctonia solani'
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1
Dignam, B. E. A., M. O'Callaghan, L. M. Condron, J. M. Raaijmakers, G. A. Kowalchuk, and S. A. Wakelin. "A bioassay to compare the disease suppressive capacity of pasture soils." New Zealand Plant Protection 68 (January 8, 2015): 151–59. http://dx.doi.org/10.30843/nzpp.2015.68.5834.
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Dynamic pathogen complexes can develop under pastures thereby substantially reducing potential productivity Suppression of such pathogen complexes is therefore of great importance and bioassays can quantify disease suppression in soils This study describes the development of a pasturerelevant system Rhizoctonia solani AG 21 induced dampingoff (wirestem) of kale (Brassica oleracea) As kale is not a component of traditional ryegrass clover pasture swards the assay allows assessment of general disease suppression considered more enduring in multiplehostmultiplepathogen systems A pathogenic Rhizoctonia solani isolate was obtained from New Zealand pastoral soil Inoculation of soils with this isolate resulted in a level of dampingoff disease comparable to that induced by reference Rhizoctonia solani isolate Rs0432 Significantly different levels of inoculuminduced disease incidence and progression were found in four distinct pastoral soils In combination with soil physicochemical data and environmental DNA approaches this bioassay can be used to further advance understanding of the influence of farm management practices on disease suppression in pasture soils
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Grosch, Rita, Franziska Faltin, Jana Lottmann, A. Kofoet, and Gabriele Berg. "Effectiveness of 3 antagonistic bacterial isolates to control Rhizoctonia solani Kühn on lettuce and potato." Canadian Journal of Microbiology 51, no. 4 (April 1, 2005): 345–53. http://dx.doi.org/10.1139/w05-002.
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Rhizoctonia solani causes yield losses in numerous economically important European crops. To develop a biocontrol strategy, 3 potato-associated ecto- and endophytically living bacterial strains Pseudomonas fluorescens B1, Pseudomonas fluorescens B2, and Serratia plymuthica B4 were evaluated against R. solani in potato and in lettuce. The disease-suppression effect of the 3 biocontrol agents (BCAs) was tested in a growth chamber and in the field. In growth chamber experiments, all 3 BCAs completely or significantly limited the dry mass (DM) losses on lettuce and the disease severity (DS) caused by R. solani on potato sprouts. Strain B1 showed the highest suppression effect (52% on average) on potato. Under field conditions, the DS on both crops, which were bacterized, decreased significantly, and the biomass losses on lettuce decreased significantly as well. The greatest disease-suppression effect on potato was achieved by strain B1 (37%), followed by B2 (33%) and then B4 (31%), whereas the marketable tuber yield increased up to 12% (B1), 6% (B2), and 17% (B4) compared with the pathogen control at higher disease pressure. Furthermore, in all experiments, B1 proved to be the most effective BCA against R. solani. Therefore, this BCA could be a candidate for developing a commercial product against Rhizoctonia diseases. To our knowledge, this is the first report on the high potential of endophytes to be used as a biological control agent against R. solani under field conditions.Key words: biocontrol, Rhizoctonia solani, field grown lettuce and potato, antagonistic bacteria, endophytes.
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Mazzola, Mark, and Yu-Huan Gu. "Wheat Genotype-Specific Induction of Soil Microbial Communities Suppressive to Disease Incited by Rhizoctonia solani Anastomosis Group (AG)-5 and AG-8." Phytopathology® 92, no. 12 (December 2002): 1300–1307. http://dx.doi.org/10.1094/phyto.2002.92.12.1300.
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The induction of disease-suppressive soils in response to specific cropping sequences has been demonstrated for numerous plant-pathogen systems. The role of host genotype in elicitation of the essential transformations in soil microbial community structure that lead to disease suppression has not been fully recognized. Apple orchard soils were planted with three successive 28-day cycles of specific wheat cultivars in the greenhouse prior to infestation with Rhizoctonia solani anastomosis group (AG)-5 or AG-8. Suppressiveness to Rhizoctonia root rot of apple caused by the introduced isolate of R. solani AG-5 was induced in a wheat cultivar-specific manner. Pasteurization of soils after wheat cultivation and prior to pathogen introduction eliminated the disease suppressive potential of the soil. Wheat cultivars that induced disease suppression enhanced populations of specific fluorescent pseudomonad genotypes with antagonistic activity toward R. solani AG-5 and AG-8, but cultivars that did not elicit a disease suppressive soil did not modify the antagonistic capacity of this bacterial community. When soils were infested prior to the initial wheat planting, all cultivars were uniformly susceptible to R. solani AG-8. However, when pathogen inoculum was added after three growth-cycles, wheat root infection during the fourth growth-cycle varied in a cultivar specific manner. The same wheat cultivar-specific response in terms of transformation of the fluorescent pseudomonad community and subsequent suppression of Rhizoctonia root rot of apple was observed in three different orchard soils. These results demonstrate the importance of host genotype in modification of indigenous saprophytic microbial communities and suggest an important role for host genotype in the success of biological control.
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Davey, Rowena S., Ann M. McNeill, Stephen J. Barnett, and Vadakattu V. S. R. Gupta. "Organic matter input influences incidence of root rot caused by Rhizoctonia solani AG8 and microorganisms associated with plant root disease suppression in three Australian agricultural soils." Soil Research 57, no. 4 (2019): 321. http://dx.doi.org/10.1071/sr18345.
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Soil-borne plant root disease caused by Rhizoctonia solani AG8 is prevalent in cereal farming systems worldwide, particularly in semiarid agricultural regions. A controlled environment study was undertaken using three Australian soils to test the hypothesis that OM input from crop roots and residues decreases infection by Rhizoctonia root rot via biologically mediated disease suppression. The specific aim was to determine the relative effect of two different OM inputs (wheat stubble or roots) on (a) abundance (DNA) of the pathogen R. solani AG8 and soil organisms putatively associated with disease suppression, and (b) incidence of Rhizoctonia root rot infection of wheat seedlings (% root infected). An increase in microbial biomass carbon (C) following OM amendment indicated a potential for enhanced general biological disease suppression in all soils. OM inputs also increased the population size (DNA) of certain bacteria and fungi putatively associated with specific suppression for Rhizoctonia root rot, suggesting a C resource-mediated change in microbial functions related to disease suppression. There were no significant changes to measured pathogens with stubble addition. However, OM inputs via root residues and rhizodeposits from living roots increased the populations of R. solani AG8 and Gaeumannomyces graminis var. tritici so that in subsequently planted wheat there was greater incidence of root disease infection and reduced plant shoot and root DM compared with that following OM input as stubble. Differences between soils in terms of plant and soil organism responses to each OM input suggest that abiotic factors modify the development of biological disease suppression and the expression of the disease.
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Wright, Peter J., Rebekah A. Frampton, Craig Anderson, and Duncan Hedderley. "Factors associated with soils suppressive to black scurf of potato caused by Rhizoctonia solani." New Zealand Plant Protection 75 (August 30, 2022): 31–49. http://dx.doi.org/10.30843/nzpp.2022.75.11761.
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Soils in which disease fails to develop despite pathogen presence are considered disease-suppressive. They offer sustainable, effective protection to plants against infection by soil-borne pathogens. Naturally disease-suppressive soils have been reported for diseases of a diverse range of agricultural crops worldwide yet the underlying mechanisms of disease suppression are still not completely understood. Two large greenhouse experiments, conducted during 2017/18 (Year 1) and 2018/19 (Year 2), determined that soils naturally suppressive to stem canker and black scurf of potato (caused by Rhizoctonia solani) are present in vegetable-arable cropping soils of the Auckland and Waikato regions of New Zealand. Soil was pre-treated with heat prior to inoculation with R. solani and compared with untreated and uninoculated controls to ascertain if stem canker and black scurf suppression was ‘general’, or ‘specific’ (i.e. transferable; possibly involving specific microorganisms). Rhizoctonia solani inoculation was also combined with transfer of one part test soil to nine parts of a known disease-conducive soil. Abiotic factors such as soil texture and organic matter content influenced black scurf incidence and severity. Soil microorganisms were also involved in disease suppression since black scurf incidence and severity markedly increased when they were eliminated or reduced by soil heat pre-treatment. Microbial profiling of the soils through sequencing revealed that taxa of geographically close soils of the same type had similar fungal and bacterial community structure and diversity even though they differed in their capacity to suppress black scurf. These results suggest that although the soil microbiome as a whole, was mainly responsible for soil disease suppressiveness, certain bacterial genera or species may play a role in black scurf suppression.
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Barnett, Stephen J., David K. Roget, and Maarten H. Ryder. "Suppression of Rhizoctonia solani AG-8 induced disease on wheat by the interaction between Pantoea, Exiguobacterium, and Microbacteria." Soil Research 44, no. 4 (2006): 331. http://dx.doi.org/10.1071/sr05113.
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Rhizoctonia solani AG-8 is a major wheat root pathogen; however, soils can become suppressive to the expression of disease under intensive cropping with retention of crop residues. This is in part due to the action of soil microorganisms. A step-wise approach was used to determine which microorganisms contributed to suppression of R. solani induced disease in a disease-suppressive soil. Using wheat-soil-pathogen bioassays it was determined that the interaction between 3 phylogenetically diverse groups of bacteria, Pantoea agglomerans, Exiguobacterium acetylicum, and Microbacteria (family Microbacteriaceae), was a major contributor to disease suppression. Inoculation of a sterilised soil with the combination of these groups resulted in greatly increased seedling shoot dry weight and reduced infection compared with diseased control plants with no bacterial inoculation, or inoculated with individual types of bacteria. These groups, however, did not reduce levels of pathogen DNA, although inoculation with suppressive soil (at 10% w/w) did reduce pathogen DNA. Root associated P. agglomerans and E. acetylicum promoted the growth of infected wheat plants and soil associated Microbacteria reduced root infection by R. solani.
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Rahman, M. A., R. Jannat, A. M. Akanda, M. A. R. Khan, and M. T. Rubayet. "Role of Chitosan in Disease Suppression, Growth and Yield of Carrot." European Journal of Agriculture and Food Sciences 3, no. 3 (May 10, 2021): 34–40. http://dx.doi.org/10.24018/ejfood.2021.3.3.266.
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An attempt was made for controlling of Rhizoctonia canker caused by Rhizoctonia solani and southern blight caused by Sclerotium rolfsii in pot and field experiments under inoculated condition and also to increase the growth promoting factors and yield of carrot through the application of chitosan. Before setting the experiments in the field, laboratory experiments were carried out to select virulent isolates of R. solani and S. rolfsii and effective dose of chitosan on mycelial growth inhibition of virulent isolates of test pathogens. In the pathogenicity test, R. solani isolate R-1 and S. rolfsii isolate S-1 were found to be the most virulent against carrot seedlings. In vitro application of 1.0% chitosan was found to inhibit 100% mycelial growth of both tested pathogens. The field experiment was laid out following randomized complete block design with four treatments, where no treatment was done in T1, pathogen was inoculated in T2 and seed treatment and soil amendment with 1.0% chitosan was done in T3 and T4, respectively, in pathogen inoculated condition. Application of 1.0% chitosan as seed treatment or soil amendment significantly reduced post-emergence seedling mortality, incidence of diseases and enhanced seedling growth and also yields of carrot. On the contrary, post-emergence seedling mortality, incidence of Rhizoctonia canker and southern blight of carrot were highest in treatment T2 where soil was inoculated with pathogens. Chitosan could be used as an alternative of fungicide to suppress Rhizoctonia canker and southern blight in sustainable agriculture and improvement the yield of carrot.
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Tewoldemedhin, Y. T., S. C. Lamprecht, and M. Mazzola. "Rhizoctonia Anastomosis Groups Associated with Diseased Rooibos Seedlings and the Potential of Compost as Soil Amendment for Disease Suppression." Plant Disease 99, no. 7 (July 2015): 1020–25. http://dx.doi.org/10.1094/pdis-11-14-1211-re.
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Rhizoctonia spp. associated with rooibos in the Western Cape province of South Africa were recovered during the 2008 season by planting seedlings in rhizosphere soils collected from 14 rooibos nurseries. In all, 75 Rhizoctonia isolates were obtained, of which 67 were multinucleate and 8 were binucleate Rhizoctonia spp. The identity of these isolates to anastomosis group (AG) was determined through sequence analysis of the ribosomal DNA internal transcribed spacer region. The collection of multinucleate isolates included representatives of AG-2-2 (67%), AG-4 HGI (14%), AG-11 (5%), and R. zeae (3%). Binucleate AGs included AG-Bo (4%) and AG-K (4%) and an unidentified binucleate Rhizoctonia (3%). Rhizoctonia solani AG-2-2 was the most widely distributed species of Rhizoctonia detected among the 11 nurseries sampled. All AGs recovered from rooibos have been previously reported on crop plants in South Africa, with the exception of R. zeae. However, this is the first study to classify the Rhizoctonia AGs recovered from rooibos. In glasshouse bioassays, the most virulent Rhizoctonia AGs on rooibos and lupin were AG-2-2, AG-4 HGI, and AG-11. Although plant damage was less than that observed for lupin and rooibos, oat was significantly affected by AG-2-2 and AG-4 HGI. Two composts sourced from independent suppliers were evaluated for disease suppression under glasshouse conditions. Compost amendment suppressed damping-off by most R. solani AGs, except for AG-4 HGI. Furthermore, within AG-2-2, suppression by compost was isolate specific.
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Davey, Rowena S., Ann M. McNeill, Stephen J. Barnett, and Vadakattu V. S. R. Gupta. "Potential for suppression of Rhizoctonia root rot is influenced by nutrient (N and P) and carbon inputs in a highly calcareous coarse-textured topsoil." Soil Research 59, no. 4 (2021): 329. http://dx.doi.org/10.1071/sr20247.
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Bioassays were undertaken in a controlled environment to assess whether the potential for suppression of Rhizoctonia root rot of wheat, in a highly calcareous topsoil, was positively influenced by nutrient (nitrogen (N) or phosphorus (P)) addition and whether any disease suppression response to augmented nutrition was affected by the addition of carbon (C), either as a readily available C source (sucrose) or as wheat stubble. The soil was P deficient, which limited plant growth, populations of putatively beneficial soil microorganisms, and microbial activity and diversity. This ultimately reduced potential for suppression of Rhizoctonia solani AG8. Addition of fertiliser P to the soil increased R. solani AG8 DNA and percent root infection but not the effectiveness of the pathogen. A positive effect of P fertiliser on plant growth partially compensated for the negative effect of increased root infection. Addition of P increased DNA for Microbacterium spp. where labile C had been added and in the presence of plant roots. Stubble addition alone, after 6 weeks of incubation, increased DNA for Pantoea agglomerans, Trichoderma A and Microbacterium spp. although differences in microbial activity and diversity between stubble treatments were only detected after the bioassay had commenced and P was added. Fertiliser P addition to stubble-amended soil resulted in less Rhizoctonia infection compared with that in soil without P or stubble addition. Effectiveness of R. solani AG8 was decreased by 50% with stubble amendment. The application of N alone did not have a marked effect on plant growth or potential for suppression of Rhizoctonia root disease. Agronomic management practices that affect quantity and lability of C input to soil, when combined with strategic P fertiliser decisions, are likely to improve the potential for development of suppression of Rhizoctonia root rot disease in cereal crops on alkaline and highly calcareous soils.
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Zinati, Gladis M. "Compost in the 20th Century: A Tool to Control Plant Diseases in Nursery and Vegetable Crops." HortTechnology 15, no. 1 (January 2005): 61–66. http://dx.doi.org/10.21273/horttech.15.1.0061.
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The discovery of disease suppression in certain bark composts increased the interest in using compost as growing substrate to control root rot diseases caused by Phytophthora cinnamomi. Disease suppression mechanisms include antibiosis, competition, hyperparasitism, and induced systemic resistance. Although abiotic factors may influence disease suppression, the latter is often based on microbial interactions—the two common mechanisms being general for pythium (Pythium spp.) and phytophthora root rot (Phytophthora spp.) and specific for rhizoctonia (Rhizoctonia solani). The discovery of disease suppression agents in compost led to the development of biocontrol agent-fortified compost during the last decade of the 20th century. The suggested recommendations for future research and extension outreach may include 1) development of methods to manage bacterial and viral diseases through the use of compost; 2) exploration of the potential effects of fortified compost on insect pests suppression; 3) improvement of inoculation methods of composts with biocontrol agents to produce consistent levels of disease suppression at the commercial scale; 4) development of effective fortified compost teas for suppressing foliar diseases; 5) education of compost producers on methods of production of fortified compost that suppress specific diseases; and 6) education of end-users on uses of fortified compost and its by-products.
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Elsharkawy, Mohsen Mohamed, Shuhei Kuno, Mitsuro Hyakumachi, Yasser S. Mostafa, Saad A. Alamri, and Sulaiman A. Alrumman. "PCR-DGGE Analysis Proves the Suppression of Rhizoctonia and Sclerotium Root Rot Due to Successive Inoculations." Journal of Fungi 8, no. 2 (January 28, 2022): 133. http://dx.doi.org/10.3390/jof8020133.
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The soil-borne pathogens Rhizoctonia solani and Sclerotium rolfsii have emerged as major pathogens of radish (Raphanus sativus) worldwide. The induction of soil suppressive of radish root rot disease was evaluated in soil repeatedly inoculated with R. solani, nonpathogenic binucleate Rhizoctonia sp. AG-A W1 (BNR) and S. rolfsii. The repeated inoculations of soil with R. solani and BNR significantly suppressed the disease severity of R. solani and S. rolfsii compared to the control. In contrast, the repeated inoculation of soil with S. rolfsii significantly suppressed only the pathogen, S. rolfsii. The community structure was examined using PCR-DGGE (polymerase chain reaction denaturing gradient gel electrophoresis) method. The bands of Trichoderma sp. were observed in the first, second and third inoculations of the soil with BNR. Similarly, bands of Trichoderma sp. were observed in the second and third inoculations of the soil with S. rolfsii and R. solani. Compared to the control, disease severity was significantly reduced in the soil repeatedly inoculated with S. rolfsii and R. solani . In conclusion, Trichoderma species were accumulated in specific patterns depending on the applied fungal inoculum in the suppressive soil.
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Bienkowski, D., A. Stewart, R. E. Falloon, M. Braithwaite, L. L. Loguercio, and E. Hicks. "A disease assay for Rhizoctonia solani on potato (Solanum tuberosum)." New Zealand Plant Protection 63 (August 1, 2010): 133–37. http://dx.doi.org/10.30843/nzpp.2010.63.6553.
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Rhizoctonia solani is an important soilborne pathogen of potato causing black scurf on tubers and shoot/stolon canker on young plants These diseases reduce the quality of fresh and seed potatoes and may harm crop establishment A pathogenicity test has been developed for the study of biological suppression of diseases caused by R solani Disease expression from two R solani isolates was assessed in potato plants grown from tissue cultured plantlets or from minitubers The isolates were cultured in two media branwater or barley grainV8 juice which were compared as inoculants of potting mix at several standardised rates The proportions of diseased stolons and necrotic shoots were determined after 7 weeks growth in a greenhouse Significantly different levels of disease incidence were found between the isolates between inoculum concentrations for one isolate and (only with minitubers) between inoculum media Rates of inoculum that produced disease levels suitable for use in biocontrol assays were determined
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Scheuerell, Steven J., Dan M. Sullivan, and Walter F. Mahaffee. "Suppression of Seedling Damping-Off Caused by Pythium ultimum, P. irregulare, and Rhizoctonia solani in Container Media Amended with a Diverse Range of Pacific Northwest Compost Sources." Phytopathology® 95, no. 3 (March 2005): 306–15. http://dx.doi.org/10.1094/phyto-95-0306.
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Suppression of seedling damping-off disease caused by Pythium spp. and Rhizoctonia solani is a potential benefit of formulating soilless container media with compost. Thirty-six compost samples from Pacific Northwest commercial composting facilities were analyzed for a number of physical, chemical, and biological properties, including suppression of damping-off caused by Pythium ultimum, P. irregulare, and R. solani. The samples were produced from diverse feedstocks and composting technol ogies; this was reflected in a large degree of variability in the measured properties. When mixed with sphagnum peat moss and inorganic aggregates, 67% of the compost samples significantly suppressed P. irregulare damping-off of cucumber, 64% suppressed P. ultimum damping-off of cucumber, and 17% suppressed damping-off of cabbage caused by R. solani. Suppression of Pythium damping-off was related to the potential of compost to support microbial activity and a qualitative index of ammonia volatilization. Suppression of Rhizoctonia damping-off was not related to any one compost factor. Currently available compost products potentially could provide commercially acceptable control of damping-off caused by Pythium spp., but it is necessary to fortify composts with microbial antagonists for the control of R. solani.
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Ghini, Raquel, and Marcelo Augusto Boechat Morandi. "Biotic and abiotic factors associated with soil suppressiveness to Rhizoctonia solani." Scientia Agricola 63, no. 2 (April 2006): 153–60. http://dx.doi.org/10.1590/s0103-90162006000200007.
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Crop management may modify soil characteristics, and as a consequence, alter incidence of diseases caused by soilborne pathogens. This study evaluated the suppressiveness to R. solani in 59 soil samples from a microbasin. Soil sampling areas included undisturbed forest, pasture and fallow ground areas, annual crops, perennial crops, and ploughed soil. The soil samples were characterized according to abiotic variables (pH; electrical conductivity; organic matter content; N total; P; K; Ca; Mg; Al; H; S; Na; Fe; Mn; Cu; Zn; B; cation exchange capacity; sum of bases and base saturation) and biotic variables (total microbial activity evaluated by the CO2 evolution and fluorescein diacetate hydrolysis; culturable bacterial, fungal, actinomycetes, protozoa, fluorescent Pseudomonas and Fusarium spp. communities). The contribution and relationships of these variables to suppression to R. solani were assessed by path analysis. When all samples were analyzed together, only abiotic variables correlated with suppression of R. solani, but the entire set of variables explained only 51% of the total variation. However, when samples were grouped and analyzed by vegetation cover, the set of evaluated variables in all cases accounted for more than 90% of the variation in suppression of the pathogen. In highly suppressive soils of forest and pasture/fallow ground areas, several abiotic variables and fluorescein diacetate hydrolysis correlated with suppression of R. solani and the set of variables explained more than 98% of suppressiveness.
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Kasuya, Masahiro, Andriantsoa R. Olivier, Yoko Ota, Motoaki Tojo, Hitoshi Honjo, and Ryo Fukui. "Induction of Soil Suppressiveness Against Rhizoctonia solani by Incorporation of Dried Plant Residues into Soil." Phytopathology® 96, no. 12 (December 2006): 1372–79. http://dx.doi.org/10.1094/phyto-96-1372.
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Suppressive effects of soil amendment with residues of 12 cultivars of Brassica rapa on damping-off of sugar beet were evaluated in soils infested with Rhizoctonia solani. Residues of clover and peanut were tested as noncruciferous controls. The incidence of damping-off was significantly and consistently suppressed in the soils amended with residues of clover, peanut, and B. rapa subsp. rapifera ‘Saori’, but only the volatile substance produced from water-imbibed residue of cv. Saori exhibited a distinct inhibitory effect on mycelial growth of R. solani. Nonetheless, disease suppression in such residue-amended soils was diminished or nullified when antibacterial antibiotics were applied to the soils, suggesting that proliferation of antagonistic bacteria resident to the soils were responsible for disease suppression. When the seed (pericarps) colonized by R. solani in the infested soil without residues were replanted into the soils amended with such residues, damping-off was suppressed in all cases. In contrast, when seed that had been colonized by microorganisms in the soils containing the residues were replanted into the infested soil, damping-off was not suppressed. The evidence indicates that the laimosphere, but not the spermosphere, is the site for the antagonistic microbial interaction, which is the chief principle of soil suppressiveness against Rhizoctonia damping-off.
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Schlatter, Daniel, Linda Kinkel, Linda Thomashow, David Weller, and Timothy Paulitz. "Disease Suppressive Soils: New Insights from the Soil Microbiome." Phytopathology® 107, no. 11 (November 2017): 1284–97. http://dx.doi.org/10.1094/phyto-03-17-0111-rvw.
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Soils suppressive to soilborne pathogens have been identified worldwide for almost 60 years and attributed mainly to suppressive or antagonistic microorganisms. Rather than identifying, testing and applying potential biocontrol agents in an inundative fashion, research into suppressive soils has attempted to understand how indigenous microbiomes can reduce disease, even in the presence of the pathogen, susceptible host, and favorable environment. Recent advances in next-generation sequencing of microbiomes have provided new tools to reexamine and further characterize the nature of these soils. Two general types of suppression have been described: specific and general suppression, and theories have been developed around these two models. In this review, we will present three examples of currently-studied model systems with features representative of specific and general suppressiveness: suppression to take-all (Gaeumannomyces graminis var. tritici), Rhizoctonia bare patch of wheat (Rhizoctonia solani AG-8), and Streptomyces. To compare and contrast the two models of general versus specific suppression, we propose a number of hypotheses about the nature and ecology of microbial populations and communities of suppressive soils. We outline the potential and limitations of new molecular techniques that can provide novel ways of testing these hypotheses. Finally, we consider how this greater understanding of the phytobiome can facilitate sustainable disease management in agriculture by harnessing the potential of indigenous soil microbes.
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Wen, L., S. Lee-Marzano, L. M. Ortiz-Ribbing, J. Gruver, G. L. Hartman, and D. M. Eastburn. "Suppression of Soilborne Diseases of Soybean With Cover Crops." Plant Disease 101, no. 11 (November 2017): 1918–28. http://dx.doi.org/10.1094/pdis-07-16-1067-re.
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Field trials were conducted from 2010 to 2013 at four locations in Illinois to evaluate the impact of cover crops (cereal rye [Secale cereal], brown mustard [Brassica juncea], winter canola [B. napus], and winter rapeseed [B. napus]) on soybean [Glycine max] stands and yield, diseases, pathogen populations, and soil microbial communities. Cover crops were established in the fall each year and terminated the following spring either by using an herbicide (no-till farms), by incorporation (organic farm), or by an herbicide followed by incorporation (research farm). Although shifts in soilborne pathogen populations and microbial community structure were not detected, cover crops were found to induce general soil suppressiveness in some circumstances. Cereal rye and rapeseed improved soybean stands in plots inoculated with Rhizoctonia solani and decreased levels of soybean cyst nematode in the soil. Cereal rye increased soil suppressiveness to R. solani and Fusarium virguliforme, as measured in greenhouse bioassays. Cereal rye significantly improved yield when Rhizoctonia root rot was a problem.
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Shimizu, Yukari, Daiki Sagiya, Mariko Matsui, and Ryo Fukui. "Zonal Soil Amendment with Simple Sugars to Elevate Soil C/N Ratios as an Alternative Disease Management Strategy for Rhizoctonia Damping-off of Sugar Beet." Plant Disease 102, no. 7 (July 2018): 1434–44. http://dx.doi.org/10.1094/pdis-09-16-1279-re.
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Effects of monosaccharide-amended soils on suppression of Rhizoctonia damping-off of sugar beet were compared under controlled experiments. Suppressive effects of glucose, fructose, sorbose, and xylose were significantly (P < 0.001) greater than that of galactose or mannose but the effect of sorbose was reduced by soil treatments with antibiotics. Saprotrophic growth of Rhizoctonia solani in the laimosphere also was suppressed by glucose, fructose, sorbose, and xylose, whereas only sorbose repressed pericarp colonization. Sugar alcohols (mannitol, sorbitol, and xylitol) neither suppressed Rhizoctonia damping-off nor halted the saprotrophic growth of the pathogen. Seed germination was not affected by any of these six monosaccharides, whereas galactose and mannose inhibited seedling emergence significantly (P < 0.001) compared with the nontreated control or other monosaccharides. Soil fertilization with inorganic nitrogen at a C/N ratio of 20:1 negated the suppressive effects of glucose and fructose on both damping-off and saprotrophic colonization but improved seedling growth in carbonized soils. Obviously, microbial competition for mineral nitrogen was responsible for disease suppression; however, it delayed seedling growth after emergence. This paradox was resolved by adding glucose to the top 1-cm surface-soil zone at a C/N ratio of 50:1 or 125:1. This protected the laimosphere, resulting in effective disease suppression while complementarily enhancing seedling growth.
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Bonanomi, Giuliano, Gaspare Cesarano, Vincenzo Antignani, Claudio Di Maio, Francesca De Filippis, and Felice Scala. "Conventional farming impairs Rhizoctonia solani disease suppression by disrupting soil food web." Journal of Phytopathology 166, no. 9 (June 26, 2018): 663–73. http://dx.doi.org/10.1111/jph.12729.
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Reddy, M. S., R. K. Hynes, and G. Lazarovits. "Relationship between in vitro growth inhibition of pathogens and suppression of preemergence damping-off and postemergence root rot of white bean seedlings in the greenhouse by bacteria." Canadian Journal of Microbiology 40, no. 2 (February 1, 1994): 113–19. http://dx.doi.org/10.1139/m94-018.
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One hundred and twenty diverse bacterial strains were screened under greenhouse conditions for their ability to protect white bean seedlings from preemergence damping-off caused by Pythium ultimum and Rhizoctonia solani and postemergence root rot by Fusarium solani f.sp. phaseoli. Preemergence mortality or root rot increased with an increase in the inoculum concentration of fungal isolates. For further testing, 200 propagules/g soil of P. ultimum, 3 propagules/g soil of R. solani, and log 3 conidia/g vermiculite of F. solani f.sp. phaseoli were used, as these rates provided an optimal level (approximately 50%) of disease severity. Bacterial strains suspended in sterile distilled water were added to pathogen-amended soil or vermiculite at log 7 colony-forming units/g soil or vermiculite prior to seeding. Final healthy stand and root rot were recorded 4 weeks after planting. Nine bacterial strains on P. ultimum, five on R. solani, and nine on F. solani f.sp. phaseoli provided significant (P = 0.05) suppression of disease severity compared with the nonbacterized control. Bacterial strains were also tested in vitro against the mycelial growth of the fungi on solid and liquid media. There was no relationship between the ability of bacterial strains to inhibit fungal vegetative growth on solid culture media and their ability to suppress pathogen activity in the greenhouse, but, for a few strains, the reduction in disease was linked to reduced growth of the pathogens in liquid media.Key words: White bean, damping-off, root rot, Pythium ultimum, Rhizoctonia solani, Fusarium solani f.sp. phaseoli.
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Baysal-Gurel, Fulya, Md Niamul Kabir, and Prabha Liyanapathiranage. "Effect of Organic Inputs and Solarization for the Suppression of Rhizoctonia solani in Woody Ornamental Plant Production." Plants 8, no. 5 (May 24, 2019): 138. http://dx.doi.org/10.3390/plants8050138.
Full textAbstract:
Soilborne diseases are the most economically significant problem faced by Southern region nursery producers. The goal of this research was to improve Rhizoctonia root rot disease management through the use of soil solarization alone and in combination with biofumigant cover crops—arugula ‘Astro’ (Eruca vesicaria ssp. sativa), mustard green ‘Amara’ (Brassica carinata), and turnip ‘Purple top forage’ (B. rapa); good quality compost and mustard meal amendment. The experiments were established as on-farm trials in 2016 and 2017 with prevalent Rhizoctonia solani population in propagation beds. All three biofumigant cover crops, arugula ‘Astro’, mustard green ‘Amara’, and turnip ‘Purple top forage’ in combination with solarization were able to reduce the Rhizoctonia root rot in flowering cherry ‘Kwanzan’ plants in nursery propagation beds. Compost amendment increased the flowering cherry rooted cuttings growth (plant weight, root weight, and plant height) compared to other treatments. Soil solarization in combination with cover crops and organic inputs could be used as part of an integrated approach to manage Rhizoctonia root rot in nursery crop propagation beds.
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Mazzola, Mark, Jack Brown, Antonio D. Izzo, and Michael F. Cohen. "Mechanism of Action and Efficacy of Seed Meal-Induced Pathogen Suppression Differ in a Brassicaceae Species and Time-Dependent Manner." Phytopathology® 97, no. 4 (April 2007): 454–60. http://dx.doi.org/10.1094/phyto-97-4-0454.
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The effect of seed meals derived from Brassica juncea, B. napus, or Sinapis alba on suppression of soilborne pathogens inciting replant disease of apple was evaluated in greenhouse trials. Regardless of plant source, seed meal amendment significantly improved apple growth in all orchard soils; however, relative differences in pathogen suppression were observed. All seed meals suppressed root infection by native Rhizoctonia spp. and an introduced isolate of Rhizoctonia solani AG-5, though B. juncea seed meal often generated a lower level of disease control relative to other seed meal types. When introduction of the pathogen was delayed until 4 to 8 weeks post seed meal amendment, disease suppression was associated with proliferation of resident Streptomyces spp. and not qualitative or quantitative attributes of seed meal glucosinolate content. Using the same experimental system, when soils were pasteurized prior to pathogen infestation, control of R. solani was eliminated regardless of seed meal type. In the case of B. juncea seed meal amendment, the mechanism of R. solani suppression varied in a temporal manner, which initially was associated with the generation of allylisothiocyanate and was not affected by soil pasteurization. Among those tested, only B. juncea seed meal did not stimulate orchard soil populations of Pythium spp. and infection of apple roots by these oomycetes. Although application of B. napus seed meal alone consistently induced an increase in Pythium spp. populations, no significant increase in Pythium spp. populations was observed in response to a composite B. juncea and B. napus seed meal amendment. Suppression of soil populations and root infestation by Pratylenchus spp. was dependent upon seed meal type, with only B. juncea providing sustained nematode control. Collectively, these studies suggest that use of a composite B. juncea and B. napus seed meal mixture can provide superior control of the pathogen complex inciting apple replant disease relative to either seed meal used alone.
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Kiptoo, Judith, Aqleem Abbas, Ayesha Munawar Bhatti, Hafiz Muhammad Usman, Munsif Ali Shad, Muhammad Umer, Muhammad Nauman Atiq, et al. "RHIZOCTONIA SOLANI OF POTATO AND ITS MANAGEMENT: A REVIEW." Plant Protection 5, no. 3 (December 30, 2021): 157–69. http://dx.doi.org/10.33804/pp.005.03.3925.
Full textAbstract:
Potatoes are an annual and the most cultivated tuberous crop worldwide. Potatoes play an important role to fulfil the world’s basic food requirements because of enriched nutrients and delicious taste. Rhizoctonia solani is the most virulent and widely distributed soil-borne fungus that causes severe yield losses of potatoes globally. Several management practices have been adopted to overcome the yield losses inflicted by this fungus. Biocontrol agents play a significant role as mycoparasites and activate defense mechanisms through disease resistance genes to suppress pathogens. Compost is also applied as a soil amendment that increases soil fertility through the addition of organic matter in soil and nutrients uptake in organic form. Besides, it is a rich source of carbon and nitrogen which can address soil erosion, nutrients and organic matter depletion issues and restores soil fertility by adding organic matter and reducing the incidence of soil-borne pathogens in the soil. Biochar utilization in the agriculture sector is increasing day by day because of its great potential for disease suppression. Both biochar and compost are used commercially to improve plant growth and suppress potato diseases caused by R. solani. Therefore, in this review, we discussed the symptoms on potatoes, epidemiology and biological characteristics of R. solani and summarized to date control strategies mainly focusing on biological, chemical, biochar and compost approaches.
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Wen, Kui, Philippe Seguin, Marc St.-Arnaud, and Suha Jabaji-Hare. "Real-Time Quantitative RT-PCR of Defense-Associated Gene Transcripts of Rhizoctonia solani-Infected Bean Seedlings in Response to Inoculation with a Nonpathogenic Binucleate Rhizoctonia Isolate." Phytopathology® 95, no. 4 (April 2005): 345–53. http://dx.doi.org/10.1094/phyto-95-0345.
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Certain isolates of nonpathogenic binucleate Rhizoctonia spp. (np-BNR) are effective biocontrol agents against seedling root rot and damping-off. Inoculation of bean seed with np-BNR strain 232-CG at sowing reduced disease symptoms in bean (Phaseolus vulgaris) seedlings caused by R. solani. Molecular analyses of the spatial expression of three defense-associated genes were carried out using real-time quantitative reverse transcription-polymerase chain reaction (QRT-PCR) assays. This method allowed accurate quantitative evaluation of transcript levels of pG101 encoding for 1,3-β-D-glucanase, gPAL1 encoding for phenylalanine ammonia lyase, and CHS17 encoding for chalcone synthase in 1- and 2-week-old bean seedlings that were inoculated simultaneously with np-BNR and infected with R. solani, and in seedlings that were singly inoculated with either fungi or not inoculated. In the seedlings that were infected with R. solani only, results revealed that, following infection, activation of all defense-associated gene transcripts was achieved with significant increases ranging from 7- to 40-fold greater than the control, depending on the defense gene and tissue analyzed. Seedlings that were treated with np-BNR and infected with R. solani had expression similar to those that were treated with np-BNR only, but the levels were significantly down-regulated compared with those that were infected with R. solani only. These findings indicate that disease suppression by np-BNR isolate is not correlated to pG101, gPAL1, and CHS17 gene activation.
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Diab, H. G., S. Hu, and D. M. Benson. "Suppression of Rhizoctonia solani on Impatiens by Enhanced Microbial Activity in Composted Swine Waste-Amended Potting Mixes." Phytopathology® 93, no. 9 (September 2003): 1115–23. http://dx.doi.org/10.1094/phyto.2003.93.9.1115.
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Peat moss-based potting mix was amended with either of two composted swine wastes, CSW1 and CSW2, at rates from 4 to 20% (vol/vol) to evaluate suppression of pre-emergence damping-off of impatiens (Impatiens balsamina) caused by Rhizoctonia solani (anastomosis group-4). A cucumber bioassay was used prior to each impatiens experiment to monitor maturity of compost as the compost aged in a curing pile by evaluating disease suppression toward both Pythium ultimum and R. solani. At 16, 24, 32, and 37 weeks after composting, plug trays filled with compost-amended potting mix were seeded with impatiens and infested with R. solani to determine suppression of damping-off. Pre-emergence damping-off was lower for impatiens grown in potting mix amended with 20% CSW1 than in CSW2-amended and nonamended mixes. To identify relationships between disease suppression and microbial parameters, samples of mixes were collected to determine microbial activity, biomass carbon and nitrogen, functional diversity, and population density. Higher rates of microbial activity were observed with increasing rates of CSW1 amendment than with CSW2 amendments. Microbial biomass carbon and nitrogen also were higher in CSW1-amended mixes than in CSW2-amended potting mixes 1 day prior to seeding and 5 weeks after seeding. Principal component analysis of Biolog-GN2 profiles showed different functional diversities between CSW1- and CSW2-amended mixes. Furthermore, mixes amended with CSW1 had higher colony forming units of fungi, endospore-forming bacteria, and oligotrophic bacteria. Our results suggest that enhanced microbial activity, functional and population diversity of stable compost-amended mix were associated with suppressiveness to Rhizoctonia damping-off in impatiens.
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Maysixteen, Rica. "EFEKTIVITAS BIOPESTISIDA BERBAHAN AKTIF TRICHODERMA HARZIANUM PADA BERBAGAI FORMULASI DAN LAMA PENYIMPANAN DALAM MENGENDALIKAN PENYAKIT DAMPING-OFF TANAMAN KEDELAI (GLYCINE MAX (L.) MERILL)." Jurnal Bioindustri 5, no. 1 (November 30, 2022): 68–80. http://dx.doi.org/10.31326/jbio.v5i1.1351.
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Rhizoctonia solani is a soil-borne pathogen found in soybean plants. The attack can cause the soybean plants to collapse. The attack phase of Rhizoctonia solani occurs in the seedling phase of soybean plants. One of the control techniques for suppressing the attack of the fungus can be done with preventive measures using biopesticides. This study aims to determine spore viability, spore density, incubation period, disease incidence, disease severity, and effectiveness of control after the application of Trichoderma harzianum active ingredient biopesticide with different storage times. The research was conducted at the HPT Green House, Faculty of Agriculture, University of Jember. The experimental design used a factorial design and was repeated 3 times. The results showed that the effect of giving fish meal formulations on the germination ability of Trichoderma harzianum, incubation period, disease incidence, disease attack, and control effectiveness at 30 days of storage was able to suppress the attack of the fungus Rhizoctonia solani. The results of the analysis test were significantly different when compared to the control treatmen.
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Clocchiatti, Anna, Silja Emilia Hannula, Muhammad Syamsu Rizaludin, Maria P. J. Hundscheid, Paulien J. A. klein Gunnewiek, Mirjam T. Schilder, Joeke Postma, and Wietse de Boer. "Impact of Cellulose-Rich Organic Soil Amendments on Growth Dynamics and Pathogenicity of Rhizoctonia solani." Microorganisms 9, no. 6 (June 12, 2021): 1285. http://dx.doi.org/10.3390/microorganisms9061285.
Full textAbstract:
Cellulose-rich amendments stimulate saprotrophic fungi in arable soils. This may increase competitive and antagonistic interactions with root-infecting pathogenic fungi, resulting in lower disease incidence. However, cellulose-rich amendments may also stimulate pathogenic fungi with saprotrophic abilities, thereby increasing plant disease severity. The current study explores these scenarios, with a focus on the pathogenic fungus Rhizoctonia solani. Saprotrophic growth of R. solani on cellulose-rich materials was tested in vitro. This confirmed paper pulp as a highly suitable substrate for R. solani, whereas its performance on wood sawdusts varied with tree species. In two pot experiments, the effects of amendment of R. solani-infected soil with cellulose-rich materials on performance of beetroot seedlings were tested. All deciduous sawdusts and paper pulp stimulated soil fungal biomass, but only oak, elder and beech sawdusts reduced damping-off of beetroot. Oak sawdust amendment gave a consistent stimulation of saprotrophic Sordariomycetes fungi and of seedling performance, independently of the time between amendment and sowing. In contrast, paper pulp caused a short-term increase in R. solani abundance, coinciding with increased disease severity for beet seedlings sown immediately after amendment. However, damping-off of beetroot was reduced if plants were sown two or four weeks after paper pulp amendment. Cellulolytic bacteria, including Cytophagaceae, responded to paper pulp during the first two weeks and may have counteracted further spread of R. solani. The results showed that fungus-stimulating, cellulose-rich amendments have potential to be used for suppression of R. solani. However, such amendments require a careful consideration of material choice and application strategy.
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Gwinn, Kimberly D., Bonnie H. Ownley, Sharon E. Greene, Miranda M. Clark, Chelsea L. Taylor, Tiffany N. Springfield, David J. Trently, James F. Green, A. Reed, and Susan L. Hamilton. "Role of Essential Oils in Control of Rhizoctonia Damping-Off in Tomato with Bioactive Monarda Herbage." Phytopathology® 100, no. 5 (May 2010): 493–501. http://dx.doi.org/10.1094/phyto-100-5-0493.
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Plants in the genus Monarda produce complex essential oils that contain antifungal compounds. The objectives of this research were to identify selections of monarda that reduce Rhizoctonia damping-off of tomato, and to determine relationships between essential oil composition of 13 monarda herbages (dried and ground leaves) and disease suppression. Herbages were grouped into five chemotypes, based on essential oil composition and effective concentrations for reducing growth by 50% for Rhizoctonia solani. Replicated and repeated disease control assays were conducted with monarda herbages in greenhouse medium, with or without Rhizoctonia. Percent survival, seedling height, and stem diameter were evaluated at 8 weeks. Survival, seedling height, and stem diameter in herbage-only treatments were not different from the control (no-herbage, no-pathogen) for most herbage treatments. In the pathogen control (no-herbage + Rhizoctonia), seedling survival was 10% that of the control. In pathogen-infested media, seedling survival ranged from 65 to 80% for treatments with thymol chemotypes and 55 to 65% for carvacrol chemotypes. Effective control of Rhizoctonia damping-off was correlated with phenolic monoterpenes; herbages classified as carvacrol chemotypes effectively protected tomato seedlings from Rhizoctonia damping-off disease without phytotoxicity. This study provides evidence that monarda herbages have potential as growing media amendments for control of Rhizoctonia damping-off disease.
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Mejdoub-Trabelsi, Boutheina, Rania Aydi-Ben Abdallah, Hayfa Jabnoun-Khiareddine, Ayed Faker, and Mejda Daami-Remadi. "Antagonizing Impact of Endophytic Fungal Isolates against Potato Black Scurf (Rhizoctonia solani)." International Journal of Phytopathology 11, no. 1 (April 30, 2022): 09–18. http://dx.doi.org/10.33687/phytopath.011.01.3897.
Full textAbstract:
Four endophytic fungal isolates, naturally associated with Solanum tuberosum L., were evaluated for their antagonistic activity against Rhizoctonia solani and their ability to suppress black scurf disease of potato tubers. To identify the potential implication of antifungal compounds in their inhibitory activity, cell-free culture filtrates were produced and tested for their antifungal potential against R. solani mycelial growth and for their protective effect against development of on potato tuber slices. Results showed that percent inhibition of R. solani mycelial growth, based on in vitro antibiosis tests, ranged between 16 to 59%. Hyphal damage and lysis were the most frequent stress responses exhibited by the target pathogen during its in vitro interactions with the potato-associated fungi tested. All Cell-free culture filtrates of tested fungi had significantly inhibited the radial growth of Rhizoctonia solani Rs20. The cell-free culture filtrates of Penicillium chrysogenum and Aspergillus niger had decreased pathogen growth by more than 60% over control. These two filtrates (P. chrysogenum and A. niger) were found to be the most effective in decreasing the decay incidence in potato slices by 36 and 40%, respectively, as compared to pathogen-inoculated and untreated control. Thus, the present study clearly demonstrated that fungal isolates, occurring ubiquitously within potato plants, may be explored as potent biocontrol agents against potato-associated fungal pathogens and as source of bioactive metabolites for R. solani suppression.
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Roget, DK. "Decline in root rot (Rhizoctonia solani AG-8) in wheat in a tillage and rotation experiment at Avon, South Australia." Australian Journal of Experimental Agriculture 35, no. 7 (1995): 1009. http://dx.doi.org/10.1071/ea9951009.
Full textAbstract:
Studies of a tillage x rotation field experiment begun in 1978 at Avon, South Australia, have demonstrated a decline in rhizoctonia root rot of wheat. In direct-drilled treatments the severity of rhizoctonia root rot culminated in 1983, with patches of poor plant growth accounting for up to 46% of the crop area, and then declined to negligible levels by 1990. Disease severity was significantly less in cultivated than direct-drilled treatments. In cultivated treatments the onset of decline was more difficult to determine, but by 1990 there was negligible rhizoctonia root rot in either tillage treatment, with no increase in disease from 1990 to 1994. Decline in rhizoctonia root rot occurred largely independent of rotation, although there were significant differences in root damage and patch area between rotations, with disease generally being more severe in wheat following pasture than following peas, medic, or wheat. When inoculum of R. solani was added to soil collected from the experimental site in 1985, wheat grown in soil from direct-drilled plots had significantly less disease than wheat grown in soil from cultivated treatments, indicating a possible development of suppression.
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Guillon, C., M. St-Arnaud, C. Hamel, and S. H. Jabaji-Hare. "Differential and systemic alteration of defence-related gene transcript levels in mycorrhizal bean plants infected with Rhizoctonia solani." Canadian Journal of Botany 80, no. 3 (March 1, 2002): 305–15. http://dx.doi.org/10.1139/b02-015.
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The role of arbuscular mycorrhizas in response of plants to soilborne root pathogens is unclear. A time course study was conducted to monitor disease development and expression of mRNA for the defence-related genes phenylalanine ammonia lyase, chalcone synthase, chalcone isomerase, and hydroxyproline-rich glycoprotein in bean (Phasoelus vulgaris L.) plants colonized by the arbuscular mycorrhizal fungus Glomus intraradices Schenck & Smith and postinfected with the soilborne pathogen Rhizoctonia solani Kühn. Precolonization of bean plants by G. intraradices did not significantly reduce the severity of rot symptoms. RNA blot analysis of the defence-related genes revealed a systemic increase in the four defence genes in response to R. solani infections. On the other hand, precolonization of bean plants with G. intraradices elicited no change in phenylalanine ammonia lyase, chalcone synthase, and chalcone isomerase transcripts. A differential and systemic alteration in the expression of all four defence genes was observed in all tissues only during the pathogenic interaction of arbuscular mycorrhizal beans. Depending on the time after infection with R. solani and the tissue examined, varying responses from stimulation to suppression to no change in transcript levels were detected.Key words: induced resistance, defence-related genes, RNA analysis, Rhizoctonia solani, Glomus intraradices.
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Abdelrhim, Abdelrazek, Yasser Mazrou, Yasser Nehela, Osama Atallah, Ranya El-Ashmony, and Mona Dawood. "Silicon Dioxide Nanoparticles Induce Innate Immune Responses and Activate Antioxidant Machinery in Wheat Against Rhizoctonia solani." Plants 10, no. 12 (December 14, 2021): 2758. http://dx.doi.org/10.3390/plants10122758.
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The phytopathogenic basidiomycetous fungus, Rhizoctonia solani, has a wide range of host plants including members of the family Poaceae, causing damping-off and root rot diseases. In this study, we biosynthesized spherical-shaped silicon dioxide nanoparticles (SiO2 NPs; sized between 9.92 and 19.8 nm) using saffron extract and introduced them as a potential alternative therapeutic solution to protect wheat seedlings against R. solani. SiO2 NPs showed strong dose-dependent fungistatic activity on R. solani, and significantly reduced mycelial radial growth (up to 100% growth reduction), mycelium fresh and dry weight, and pre-, post-emergence damping-off, and root rot severities. Moreover, the impact of SiO2 NPs on the growth of wheat seedlings and their potential mechanism (s) for disease suppression was deciphered. SiO2 NPs application also improved the germination, vegetative growth, and vigor indexes of infected wheat seedlings which indicates no phytotoxicity on treated wheat seedlings. Moreover, SiO2 NPs enhanced the content of the photosynthetic pigments (chlorophylls and carotenoids), induced the accumulation of defense-related compounds (particularly salicylic acid), and alleviated the oxidative stress via stimulation of both enzymatic (POD, SOD, APX, CAT, and PPO) and non-enzymatic (phenolics and flavonoids) antioxidant defense machinery. Collectively, our findings demonstrated the potential therapeutic role of SiO2 NPs against R. solani infection via the simultaneous activation of a multilayered defense system to suppress the pathogen, neutralize the destructive effect of ROS, lipid peroxidation, and methylglyoxal, and maintain their homeostasis within R. solani-infected plants.
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Sharma, K. K. "Induction of systemic resistance (ISR) against sheath blight of rice caused by Rhizoctonia solani Kuhn using biological seed treatment with Trichoderma." Journal of Applied and Natural Science 9, no. 3 (September 1, 2017): 1861–65. http://dx.doi.org/10.31018/jans.v9i3.1453.
Full textAbstract:
Sheath blight caused by Rhizoctonia solani Kuhn has recently noticed one of the most important diseases of rice on almost all the high yielding varieties in major rice growing area. In our study morphologically and molecu-larly characterized thirty rhizospheric isolates of Trichoderma (T. harzianum and T. virens) from different locations of Uttarakhand were evaluated for their mycoparasitic ability, disease (sheath blight) suppressing potential and inducing systemic resistance against Rhizoctonia solani. Maximum inhibition in hyphal growth (58.9 %) against R. solani was recorded with isolate PB 2 followed by PB 3 (53.4 %) in confrontation assay. Under glass house con-dition, minimum disease severity (13.6%) was recorded in the treatment where seeds were treated with PB 22 and this treatment also exhibited highest total phenol content (394 μl/g) 168 hours after pathogen inoculation. Total phenol content was also increased maximally (466 μl/g) before pathogen inoculation in the treatment where seeds were treated with PB 22. Moreover, high quality ISR activity was recorded with isolates PB 21, 3, 1, 4, 23, 2 and 16 as they reduced more than 34 percent disease and total phenol contents 456 μl/g, 449 μl/g, 442 μl/g, 440 μl/g and 440 μl/g, 438 μl/g and 431 μl/g were recorded for respective isolates indicated induction of resistance in paddy against sheath blight disease caused by R. solani.
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Chowdhury, Soumitra Paul, Jenny Uhl, Rita Grosch, Sylvia Alquéres, Sabrina Pittroff, Kristin Dietel, Philippe Schmitt-Kopplin, Rainer Borriss, and Anton Hartmann. "Cyclic Lipopeptides of Bacillus amyloliquefaciens subsp. plantarum Colonizing the Lettuce Rhizosphere Enhance Plant Defense Responses Toward the Bottom Rot Pathogen Rhizoctonia solani." Molecular Plant-Microbe Interactions® 28, no. 9 (September 2015): 984–95. http://dx.doi.org/10.1094/mpmi-03-15-0066-r.
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The commercially available inoculant Bacillus amyloliquefaciens FZB42 is able to considerably reduce lettuce bottom rot caused by Rhizoctonia solani. To understand the interaction between FZB42 and R. solani in the rhizosphere of lettuce, we used an axenic system with lettuce bacterized with FZB42 and inoculated with R. solani. Confocal laser scanning microscopy showed that FZB42 could delay the initial establishment of R. solani on the plants. To show which secondary metabolites of FZB42 are produced under these in-situ conditions, we developed an ultra-high performance liquid chromatography coupled to time of flight mass spectrometry–based method and identified surfactin, fengycin, and bacillomycin D in the lettuce rhizosphere. We hypothesized that lipopeptides and polyketides play a role in enhancing the plant defense responses in addition to the direct antagonistic effect toward R. solani and used a quantitative real-time polymerase chain reaction–based assay for marker genes involved in defense signaling pathways in lettuce. A significant higher expression of PDF 1.2 observed in the bacterized plants in response to subsequent pathogen challenge showed that FZB42 could enhance the lettuce defense response toward the fungal pathogen. To identify if surfactin or other nonribosomally synthesized secondary metabolites could elicit the observed enhanced defense gene expression, we examined two mutants of FZB42 deficient in production of surfactin and the lipopetides and polyketides, by expression analysis and pot experiments. In the absence of surfactin and other nonribosomally synthesized secondary metabolites, there was no enhanced PDF 1.2–mediated response to the pathogen challenge. Pot experiment results showed that the mutants failed to reduce disease incidence in lettuce as compared with the FZB42 wild type, indicating, that surfactin as well as other nonribosomally synthesized secondary metabolites play a role in the actual disease suppression and on lettuce health. In conclusion, our study showed that nonribosomally synthesized secondary metabolites of FZB42 are actually produced in the lettuce rhizosphere and contribute to the disease suppression by mediating plant defense gene expression toward the pathogen R. solani.
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Charova, Spyridoula N., Fredrik Dölfors, Louise Holmquist, Panagiotis N. Moschou, Christina Dixelius, and Georgios Tzelepis. "The RsRlpA Effector Is a Protease Inhibitor Promoting Rhizoctonia solani Virulence through Suppression of the Hypersensitive Response." International Journal of Molecular Sciences 21, no. 21 (October 29, 2020): 8070. http://dx.doi.org/10.3390/ijms21218070.
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Rhizoctonia solani (Rs) is a soil-borne pathogen with a broad host range. This pathogen incites a wide range of disease symptoms. Knowledge regarding its infection process is fragmented, a typical feature for basidiomycetes. In this study, we aimed at identifying potential fungal effectors and their function. From a group of 11 predicted single gene effectors, a rare lipoprotein A (RsRlpA), from a strain attacking sugar beet was analyzed. The RsRlpA gene was highly induced upon early-stage infection of sugar beet seedlings, and heterologous expression in Cercospora beticola demonstrated involvement in virulence. It was also able to suppress the hypersensitive response (HR) induced by the Avr4/Cf4 complex in transgenic Nicotiana benthamiana plants and functioned as an active protease inhibitor able to suppress Reactive Oxygen Species (ROS) burst. This effector contains a double-psi beta-barrel (DPBB) fold domain, and a conserved serine at position 120 in the DPBB fold domain was found to be crucial for HR suppression. Overall, R. solani seems to be capable of inducing an initial biotrophic stage upon infection, suppressing basal immune responses, followed by a switch to necrotrophic growth. However, regulatory mechanisms between the different lifestyles are still unknown.
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El-kazzaz, Mohamed Kamal, Kamal Elsayed Ghoneim, Mohamed Khaled Mohamed Agha, Asmaa Helmy, Said I. Behiry, Ahmed Abdelkhalek, Muhammad Hamzah Saleem, Abdulaziz A. Al-Askar, Amr A. Arishi, and Mohsen Mohamed Elsharkawy. "Suppression of Pepper Root Rot and Wilt Diseases Caused by Rhizoctonia solani and Fusarium oxysporum." Life 12, no. 4 (April 14, 2022): 587. http://dx.doi.org/10.3390/life12040587.
Full textAbstract:
Pepper is vulnerable to soil-borne fungal pathogens such as Rhizoctonia solani and Fusarium oxysporum. The potential of beneficial rhizosphere microorganisms to control R. solani and F. oxysporum f.sp. capsici was evaluated in pepper plants. Paenibacillus polymyxa and Trichoderma longibrachiatum were isolated from rhizospheric soil samples of healthy pepper plants. In vitro, both isolates caused clear reductions in the radial growth of root rot and wilt pathogens. Scanning electron microscopy displayed lysis and abnormal shape of the pathogens in dual cultures with P. polymyxa and T. longibrachiatum. The incidence and severity of root rot and wilt diseases were significantly reduced in pepper plants treated with the growth-promoting fungi (PGPF isolates; Fusarium equiseti GF19-1, Fusarium equiseti GF18-3, and Phoma sp. GS8-3), P. polymyxa, or T. longibrachiatum in comparison to the control. Moreover, the induction treatments led to increased pepper growth compared with their control. The defense related gene (CaPR4) expression was shown to be significantly higher in the treated plants than in the control plants. In conclusion, the antagonistic isolates (P. polymyxa and T. longibrachiatum) and PGPF isolates have a clear impact on the prevention of root rot and wilt diseases in pepper plants incited by R. solani and F. oxysporum f.sp. capsici. The expression of the CaPR4 gene added to the evidence that PGPF isolates generate systemic resistance to pathogen infections.
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ANEES, MUHAMMAD, MUHAMMAD ABID, SOBIA CHOHAN, MUHAMMAD JAMIL, NADEEM AHMED, LIXIN ZHANG, and EUI SHIK RHA. "In situ Impact of the Antagonistic Fungal Strain, Trichoderma gamsii T30 on the Plant Pathogenic Fungus, Rhizoctonia solani in Soil." Polish Journal of Microbiology 68, no. 2 (June 10, 2019): 211–16. http://dx.doi.org/10.33073/pjm-2019-021.
Full textAbstract:
Rhizoctonia solani is a soil-borne fungus causing a wide range of plants diseases. Trichoderma gamsii strain T30 has previously been reported as antagonistic against R. solani. Although there are a few studies about the influence of Trichoderma strains on the R. solani densityin a pathosystem in the presence of plant hosts, this report for the first time comprehensively describes in situ effects of a T. gamsii strain on the population density of R. solani in the soil microcosmic conditions. The population dynamics of R. solani were followed in the autoclaved and non-autoclaved soils in artificially prepared microcosms up to day 25 after co-inoculation with T. gamsii in the variable ratios (R1/T1; R1/T0.1; R1/T0.01 of R. solani/T. gamsii). The population density of R. solani was evaluated by qPCR. In the autoclaved soil, target DNA copies of R. solani increased in the control samples from 1 × 105 to 6.5 × 106. At R1/T0.01, the number of target DNA copies were not significantly changed until day 11; however, it decreased by around five times at day 25. At R1/T0.1 and R1/T1, the number of DNA copies was reduced to 2.1 × 106 and 7.6 × 105 at day 11, respectively and the reduction was as much as 17 times at day 25. In the non-autoclaved soil, the number of the fungal cells decreased at day 25 whether inoculated or not with Trichoderma indicating a general suppression by the soil microbiome. In brief, T. gamsii significantly inhibited the growth of R. solani in the soil in situ and there was a general suppressive effect of the natural microbiome.
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ERDEVİL, Aysel Zübeyde, and Ali ERKILIÇ. "Investigation of chemical and biological control possibilities of stem canker and black scurf (Rhizoctonia solani) diseases in potatoes." Mustafa Kemal Üniversitesi Tarım Bilimleri Dergisi 27, no. 2 (July 26, 2022): 253–65. http://dx.doi.org/10.37908/mkutbd.1080205.
Full textAbstract:
Aims: In this study, it was aimed to determine the effects of various chemical fungicides, plant activators and biological preparats on the suppression of mycelial growth and disease incidence caused by stem canker and black scurf pathogen Rhizoctonia solani. Methods and Results: In the experiment, the effects of fungicides (flutolanil, fluxapyroxad, fludioxonil, penflufen+Prothiconazole and tolclophos-methyl+thiram) and plant activators (ISR-2000, Crop-set, Aliette and Messenger Gold) on the mycelial growth of R. solani were determined under laboratory conditions. The antagonistic effects of biological preparats (T-22 Planter Box, Trianum-p, Serenade and Cedriks) against R. solani were also investigated. The effects of chemicals and biological preparats on the disease of R. solani were evaluated with micro-plot trials. According to the in vitro results; fungicides tolclophos-methyl+thiram and flutolanil inhibited mycelial growth 100% from 5 ppm. Among plant activators, the highest fungicidal effect was caused in Aliette with 31.5% inhibition at 1000 ppm. Commercial bio-fungal preparat Trichoderma harzianum, suppressed mycelial growth at varying rates between 3.8% and 66.9%. Commercial bio-bacterial preparats, Pseudomonas fluorescens (Cedriks) and Bacillus subtilis (Serenade) inhibited mycelial growth by 82.9% and 59.4% respectively. According to the results of micro plot experiments, the most successful treatments were determined as tolclophos-methyl+thiram, fosetyl-al and P. fluorescens. Conclusions: Among tested treatments, Tolclophos-methyl+thiram, fosetyl-Al and P. fluorescens treatments significantly suppressed the growth of R. solani both in vitro and in vivo. Significance and Impact of the Study: Although fungicides were found to be quite effective in laboratory conditions, they showed similar fungicidal effect as shown by plant activators and biological preparats in field conditions. Considering this effect, it is possible to say that plant activators and biological preparats may have potential as an alternative control method to registered fungicides.
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Hwang, J., and D. M. Benson. "Biocontrol of Rhizoctonia Stem and Root Rot of Poinsettia with Burkholderia cepacia and Binucleate Rhizoctonia." Plant Disease 86, no. 1 (January 2002): 47–53. http://dx.doi.org/10.1094/pdis.2002.86.1.47.
Full textAbstract:
Strategies for applying Burkholderia cepacia (strain 5.5B) and Pesta formulations of binucleate Rhizoctonia (BNR) isolates (BNR621 and P9023) were evaluated for biocontrol of Rhizoctonia stem and root rot of poinsettia caused by R. solani. During propagation, one application of B. cepacia suppressed stem rot, while application of either isolate of BNR did not. In contrast, after transplanting rooted poinsettias, one application of either BNR isolate was more effective for suppression of stem and root rot than application of B. cepacia. Sequential application of B. cepacia at propagation followed by a BNR isolate at transplanting was more effective over the crop production cycle than multiple applications of one biocontrol agent or combination application of both biocontrol agents. Root colonization by both biocontrol agents after transplanting rooted poinsettias was affected by application strategy. The least root colonization by both biocontrol agents occurred in the combination application. The highest root colonization by the BNR isolates was observed in the sequential application that provided the most effective disease control. Application of different biocontrol agents during the different production phases of poinsettia was effective for disease control, but understanding the interaction between biocontrol agents and root colonization was important to develop the best application strategy.
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D'aes, Jolien, Gia Khuong Hoang Hua, Katrien De Maeyer, Joke Pannecoucque, Ilse Forrez, Marc Ongena, Lars E. P. Dietrich, Linda S. Thomashow, Dmitri V. Mavrodi, and Monica Höfte. "Biological Control of Rhizoctonia Root Rot on Bean by Phenazine- and Cyclic Lipopeptide-Producing Pseudomonas CMR12a." Phytopathology® 101, no. 8 (August 2011): 996–1004. http://dx.doi.org/10.1094/phyto-11-10-0315.
Full textAbstract:
Pseudomonas CMR12a was previously selected as an efficient biocontrol strain producing phenazines and cyclic lipopeptides (CLPs). In this study, biocontrol capacity of Pseudomonas CMR12a against Rhizoctonia root rot of bean and the involvement of phenazines and CLPs in this ability were tested. Two different anastomosis groups (AGs) of Rhizoctonia solani, the intermediately aggressive AG 2-2 and the highly aggressive AG 4 HGI, were included in growth-chamber experiments with bean plants. The wild-type strain CMR12a dramatically reduced disease severity caused by both R. solani AGs. A CLP-deficient and a phenazine-deficient mutant of CMR12a still protected bean plants, albeit to a lesser extent compared with the wild type. Two mutants deficient in both phenazine and CLP production completely lost their biocontrol activity. Disease-suppressive capacity of CMR12a decreased after washing bacteria before application to soil and thereby removing metabolites produced during growth on plate. In addition, microscopic observations revealed pronounced branching of hyphal tips of both R. solani AGs in the presence of CMR12a. More branched and denser mycelium was also observed for the phenazine-deficient mutant; however, neither the CLP-deficient mutant nor the mutants deficient in both CLPs and phenazines influenced hyphal growth. Together, results demonstrate the involvement of phenazines and CLPs during Pseudomonas CMR12a-mediated biocontrol of Rhizoctonia root rot of bean.
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Nofal, Ashraf M., Mohamed Abd El-Rahman, Asmaa A. Alharbi, and Tarek M. Abdelghany. "Ecofriendly method for suppressing damping-off disease caused by Rhizoctonia solani using compost tea." BioResources 16, no. 3 (July 29, 2021): 6378–91. http://dx.doi.org/10.15376/biores.16.3.6378-6391.
Full textAbstract:
Compost tea has a lot of potential for sustainable agriculture. The suppressive effect of compost tea on damping-off disease in beans (Phaseolus vulgaris), caused by Rhizoctonia solani, was investigated. The physicochemical properties of the tested compost tea showed the presence of dissolved solids (7070 mgL-1), organic matter (1280 mgL-1), nitrate (3840 mgL-1), and ammonium (90.0 mgL-1). The concentrations of phosphorus, potassium, calcium, and magnesium in compost tea were 22.7, 1540, 214, and 2.40 mgL-1, respectively. The highest inhibition of R. solani growth at a concentration of 30% compost tea filtrate was 87.0% and it was completely inhibited at a concentration of 50%. The application of compost tea or chemical fungicide (Rizolex-T) significantly decreased the pre- and post-emergence of damping-off and enhanced the plants survival. In spite of the total phenol content in bean plants infected with R. solani (15.6 µg·g-1 fresh weight), the treatment of infected plants using compost tea and the Rizolex-T caused further elevation in the phenol content, to 17.5 and 14.7 µg·g-1 fresh weight, respectively. These findings support the use of compost tea as a potential alternative to synthetic fungicides to help achieve environmental sustainability and food safety in farming.
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Larkin, Robert P., and Marin T. Brewer. "Effects of Crop Rotation and Biocontrol Amendments on Rhizoctonia Disease of Potato and Soil Microbial Communities." Agriculture 10, no. 4 (April 14, 2020): 128. http://dx.doi.org/10.3390/agriculture10040128.
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Rotation crops and biocontrol amendments were investigated for suppression of Rhizoctonia solani on potato (Solanum tuberosum) and their interactive effects on soil microbial communities. Greenhouse trials were conducted to evaluate selected rotation crops, including barley, common and “Lemtal” ryegrass, clover, potato, and combinations of barley with ryegrass or clover, for their effects on populations of R. solani and Rhizoctonia disease. Potato and clover preceding potato resulted in higher disease severity than most other rotations, whereas ryegrass reduced stem canker severity. In addition, all ryegrass treatments resulted in substantially higher populations of R. zeae. Field trials evaluating selected biocontrol treatments in combination with different rotations were conducted at two locations in Maine. Potatoes were treated with the biocontrol organisms Laetisaria arvalis, Trichoderma virens, or Bacillus subtilis and planted following rotation crops of barley and ryegrass, barley and clover, or potato. The barley/ryegrass rotation significantly reduced incidence and severity of stem canker and increased tuber yield at one location. Efficacy of the biocontrol treatments varied by rotation and location, with L. arvalis and T. virens reducing black scurf in some rotations and increasing some aspects of tuber yield at one location. Soil microbial community characteristics differed among rotation crops and biocontrol treatments. Significant crop by biocontrol interactions were observed demonstrating the complex interactions among rotation crops, biocontrol treatments, and soil microbial communities, as well as indicating that biocontrol can be enhanced within beneficial rotations.
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Poleatewich, Anissa, Isobel Michaud, Brian Jackson, Matthew Krause, and Liza DeGenring. "The Effect of Peat Moss Amended with Three Engineered Wood Substrate Components on Suppression of Damping-Off Caused by Rhizoctonia solani." Agriculture 12, no. 12 (December 6, 2022): 2092. http://dx.doi.org/10.3390/agriculture12122092.
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The use of wood-derived materials in soilless substrates for horticultural crop production is increasing; however, there is little information about the effects of wood on the incidence and severity of soilborne diseases of container-grown plants. The objectives of this research were to compare three differently processed wood substrate components blended with sphagnum peat and to investigate the effect of the peat:wood blend ratio on damping-off disease caused by Rhizoctonia solani using radish as a model system. In objective one, raw sphagnum peat was blended with three types of processed pine wood, screw-extruded, twin disc-refined, and hammer-milled, at a volumetric ratio of 70:30 and compared to a 70:30 peat:perlite mix. Radish plants grown in the hammer-milled wood and disc-refined wood had significantly lower damping-off disease severity compared to plants grown in the peat–perlite control. In objective two, sphagnum peat was blended with the three types of processed wood at a volumetric ratio of 90:10, 80:20, and 70:30 and compared to a 70:30 peat–perlite mix. The effect of the blend ratio varied by wood processing type. Higher percentages of Forest Gold and pine tree substrate resulted in lower disease severity. In both objectives, radish plants grown in any of the substrate treatments containing wood infested with R. solani tended to have lower disease severity compared to plants in the control. Results of this study indicate that the blending of processed pine wood-derived components into peat may enhance the natural suppression of damping-off disease of radish. Further research is needed to elucidate the mode of action of wood-derived materials on disease suppression in container-grown crops and to study the effects for other plant pathogens and crop species.
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Hewavitharana, Shashika S., and Mark Mazzola. "Carbon Source-Dependent Effects of Anaerobic Soil Disinfestation on Soil Microbiome and Suppression of Rhizoctonia solani AG-5 and Pratylenchus penetrans." Phytopathology® 106, no. 9 (September 2016): 1015–28. http://dx.doi.org/10.1094/phyto-12-15-0329-r.
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The effect of carbon source on efficacy of anaerobic soil disinfestation (ASD) toward suppression of apple root infection by Rhizoctonia solani AG-5 and Pratylenchus penetrans was examined. Orchard grass (GR), rice bran (RB), ethanol (ET), composted steer manure (CM), and Brassica juncea seed meal (SM) were used as ASD carbon inputs, with plant assays conducted in natural and pasteurized orchard soils. Subsequent studies investigated the effect of GR application rate used in ASD on control of these pathogens. In general, apple root infection by R. solani AG-5 was significantly lower in ET, GR, RB, and SM ASD treatments compared with the control. Among different ASD treatments, apple seedling growth was significantly greater when GR or SM was used as the carbon input relative to all other ASD treatments. R. solani AG-5 DNA abundance was significantly reduced in all ASD treatments, regardless of amendment type, compared with the control. In independent experiments, ASD-GR was consistently superior to ASD-CM for limiting pathogen activity in soils. ASD treatment with a grass input rate of 20 t ha−1 provided superior suppression of P. penetrans but grass application rate did not affect ASD efficacy in control of R. solani AG-5. The soil microbiome from ASD-GR-treated soils was clearly distinct from the control and ASD-CM-treated soils. In contrast, composition of the microbiome from control and ASD-CM-treated soils could not be differentiated. Comparative results from pasteurized and nonpasteurized soils suggest that there is potential for GR based ASD treatment to recruit microbial elements that persist over the anaerobic phase of soil incubation, which may functionally contribute to disease suppression. When ASD was conducted with GR, microbial diversity was markedly reduced relative to the control or ASD-CM soil suggesting that this parameter, typically associated with system resilience, was not instrumental to the function of ASD-induced soil suppressiveness.
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Copes, Warren E., and H. Scherm. "Plant Spacing Effects on Microclimate and Rhizoctonia Web Blight Development in Container-grown Azalea." HortScience 40, no. 5 (August 2005): 1408–12. http://dx.doi.org/10.21273/hortsci.40.5.1408.
Full textAbstract:
Rhizoctonia web blight, caused by Rhizoctonia solani and binucleate Rhizoctonia spp., is an annual problem in compact cultivars of container-grown azalea (Rhododendron spp.) in the Gulf Coast states. Increasing the space between plants is commonly recommended for suppression of the disease, but experimental evidence for the effectiveness of this cultural practice in container-grown azalea is lacking. During the summers of 2002 and 2003, disease severity was measured weekly in the inoculated center plant of plots consisting of 49 potted `Gumpo White' azalea plants growing in 3.8-L containers and having a canopy diameter of about 30 cm. Plant spacing within plots was 0, 6, 12, 18, or 24 cm, and plots were arranged in three randomized complete blocks. Evaporation, leaf wetness (LW), relative humidity (RH), and temperature were monitored in each plot. Disease severity increased steadily from mid-July to late August or early September, after which it leveled off or declined. Evaporation increased and the number of hours within the temperature range favorable for disease development (25 to 30 °C) decreased significantly with plant spacing (P < 0.05), but LW and RH were not significantly different among treatments. Plant spacing also had no significant effect on disease severity. Daily overhead irrigation and compact plant form likely contributed to the lack of effect of spacing on disease development.
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Schillinger, W. F., and T. C. Paulitz. "Reduction of Rhizoctonia Bare Patch in Wheat with Barley Rotations." Plant Disease 90, no. 3 (March 2006): 302–6. http://dx.doi.org/10.1094/pd-90-0302.
Full textAbstract:
Rhizoctonia bare patch caused by Rhizoctonia solani AG-8 is a major fungal root disease in no-till cropping systems. In an 8-year experiment comparing various dryland no-till cropping systems near Ritzville, WA, Rhizoctonia bare patch first appeared in year 3 and continued unabated through year 8. Crop rotation had no effect on bare patch during the first 5 years. However, from years 6 to 8, both soft white and hard white classes of spring wheat (Triticum aestivum L.) grown in a 2-year rotation with spring barley (Hordeum vulgare L.) had an average of only 7% of total land area with bare patches compared with 15% in continuous annual soft white wheat or hard white wheat (i.e., monoculture wheat). In years 6 to 8, average grain yield of both soft white wheat and hard white wheat were greater (P < 0.001) when grown in rotation with barley than in monoculture. Although both classes of wheat had less bare patch area and greater grain yield when grown in rotation with barley, monoculture hard white wheat was more severely affected by Rhizoctonia than soft white wheat. Soil water levels were higher in bare patches, indicating that roots of healthy cereals did not grow into or underneath bare patch areas. This is the first documentation of suppression of Rhizoctonia bare patch disease in low-disturbance no-till systems with rotation of cereal crops.
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Nuryanto, Bambang. "Penyakit Hawar Pelepah (Rhizoctonia solani) pada Padi dan Taktik Pengelolaannya." Jurnal Perlindungan Tanaman Indonesia 21, no. 2 (January 8, 2018): 63. http://dx.doi.org/10.22146/jpti.22494.
Full textAbstract:
Rice sheath blight disease caused by Rhizoctonia solani Kuhn (AG-1), is one of diseases currently growing and widespread in rice-producing areas in Indonesia. Widely planting of short-type and many tillers rice varieties with high doses fertilized, especially urea, can increase the severity of sheath blight disease. Sheath blight disease is becoming increasingly important role in the rice production system, especially in intensive rice farming. Therefore, it is necessary to analyze epidemic components affecting sheath blight development to determine their management strategies. The sheath blight disease is observed to develop more severe in low areas (0−200 m above sea levels) than in the moderate and high areas, severity of disease is seen to increase in short-type many tillers rice varieties. Initial inoculum are sclerotia and the mycelia in plant debris that have an important role in the rice sheath blight development. However, sclerotia may fail to germinate due colonized by various kinds of antagonistic bacteria in the soil. Bacteria that are antagonistic to R. solani can be isolated from paddy soil containing compost. Mature compost can suppress germination of sclerotia of R. solani by 14%, while in the mature compost enriched with antagonistic bacteria can suppress the germination of sclerotia by 28%. Relative humidity and temperature around the plant affect the development of rice sheath blight disease. Relative humidity decreased 2.8% when watering is only done by flooding the trench around, and decreased by 4.4% when flooding of land only 1 time per week. Sheath blight control by implementing some components in an integrated epidemic have higher chances of success in suppressing the disease development. IntisariPenyakit hawar pelepah padi yang disebabkan oleh jamur Rhizoctonia solani Kuhn (AG-1), merupakan salah satu penyakit yang saat ini berkembang dan tersebar luas di daerah-daerah penghasil padi di Indonesia. Penanaman secara luas padi varietas unggul tipe pendek beranakan banyak dan dipupuk dengan dosis tinggi terutama urea, dapat meningkatkan keparahan penyakit hawar pelepah. Penyakit hawar pelepah menjadi semakin penting peranannya di dalam sistem produksi padi sawah, terutama di daerah pertanian padi yang intensif. Oleh karena itu, perlu analisis komponen epidemi yang memengaruhi perkembangan hawar pelepah untuk menentukan strategi pengelolaannya. Pengamatan menunjukkan bahwa hawar pelepah berkembang lebih parah di daerah rendah (0−200 m dpl) daripada di daerah sedang dan tinggi, keparahan penyakit terlihat semakin meningkat pada varietas padi tipe pendek beranakan banyak. Inokulum awal berupa sklerosia dan miselium dalam serasah tanaman mempunyai peranan penting dalam perkembangan penyakit di pertanaman. Akan tetapi, sklerosia dapat gagal berkecambah karena dikoloni oleh berbagai spesies bakteri antagonis dalam tanah. Bakteri yang bersifat antagonis terhadap R. solani dapat diisolasi dari tanah sawah yang mengandung kompos. Kompos matang dapat menekan perkecambahan sklerosia sebesar 14%, sedangkan pada kompos matang yang diperkaya dengan bakteri antagonis dapat menekan perkecambahan sklerosia sebesar 28%. Kelembapan relatif dan suhu di sekitar tanaman padi memengaruhi perkembangan penyakit hawar pelepah. Kelembapan relatif menurun 2,8% ketika pengairan hanya dilakukan dengan cara penggenangan pada parit keliling, dan turun sebesar 4,4% ketika dilakukan penggenangan lahan 1 kali seminggu. Teknologi pengendalian hawar pelepah dengan menerapkan beberapa komponen epidemik secara terpadu mempunyai peluang keberhasilan tinggi dalam menekan perkembangan penyakit.
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Yin, Chuntao, Scot H. Hulbert, Kurtis L. Schroeder, Olga Mavrodi, Dmitri Mavrodi, Amit Dhingra, William F. Schillinger, and Timothy C. Paulitz. "Role of Bacterial Communities in the Natural Suppression of Rhizoctonia solani Bare Patch Disease of Wheat (Triticum aestivum L.)." Applied and Environmental Microbiology 79, no. 23 (September 20, 2013): 7428–38. http://dx.doi.org/10.1128/aem.01610-13.
Full textAbstract:
ABSTRACTRhizoctoniabare patch and root rot disease of wheat, caused byRhizoctonia solaniAG-8, develops as distinct patches of stunted plants and limits the yield of direct-seeded (no-till) wheat in the Pacific Northwest of the United States. At the site of a long-term cropping systems study near Ritzville, WA, a decline inRhizoctoniapatch disease was observed over an 11-year period. Bacterial communities from bulk and rhizosphere soil of plants from inside the patches, outside the patches, and recovered patches were analyzed by using pyrosequencing with primers designed for 16S rRNA. Taxa in the classAcidobacteriaand the genusGemmatimonaswere found at higher frequencies in the rhizosphere of healthy plants outside the patches than in that of diseased plants from inside the patches.DyellaandAcidobacteriasubgroup Gp7 were found at higher frequencies in recovered patches.Chitinophaga,Pedobacter,Oxalobacteriaceae(DuganellaandMassilia), andChyseobacteriumwere found at higher frequencies in the rhizosphere of diseased plants from inside the patches. For selected taxa, trends were validated by quantitative PCR (qPCR), and observed shifts of frequencies in the rhizosphere over time were duplicated in cycling experiments in the greenhouse that involved successive plantings of wheat inRhizoctonia-inoculated soil.Chryseobacterium soldanellicolawas isolated from the rhizosphere inside the patches and exhibited significant antagonism againstR. solaniAG-8in vitroand in greenhouse tests. In conclusion, we identified novel bacterial taxa that respond to conditions affecting bare patch disease symptoms and that may be involved in suppression ofRhizoctoniaroot rot and bare batch disease.
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Srđanov, Jovana. "The possibility of using biochar in plant protection from pathogens." Biljni lekar 50, no. 5 (2022): 322–33. http://dx.doi.org/10.5937/biljlek2205322s.
Full textAbstract:
Literature review showed, that the utilization of organic amendments has been proposed to decrease the incidence of plant diseases caused by soilborne pathogens. Biochar can be effective against both soilborne pathogens (e.g. Fusarium spp., Phytophthora spp., Rhizoctonia solani) and airborne (e.g. Botrytis cinerea, different species of powdery mildew). Five different mechanisms have been pro posed to explain biochar disease suppression: (1)-induction of systemic resistance in host plants; (2)enhanced abundance and activities of beneficial microbes, including mycorrhizal fungi; (3)-modification of soil quality in terms of nutrient availability and abiotic conditions such as liming eff ECT; (4)-direct fungitoxic effect of biochar; (5)-sorption of allelopathic, phytotoxic compounds that can directly harm plant roots and thus promote pathogen attacks. Potential side-effects of biochar have been reported, like the possibility of absorbing agrochemicals like herbicides, insecticides and fungicides, thus reducing their efficacy. A lot of investigations on the mechanisms underlying biochar disease suppression, as well as long-term field experiments, are very needed to make biochar a safe, affordable and effective tool for the control of these plant pathogens.
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Roekhan, Achmad, Ayu Ike Dayanti, Rahmania Oktaviani, Fibrianti Shinta, Nabilla Alya Anastasia, and Luqman Qurata Aini. "The Potency of UB Forest Chitinolytic Bacteria to Promote Plant Growth and Inhibit Damping off Disease on Soybean." Research Journal of Life Science 8, no. 1 (April 1, 2021): 25–33. http://dx.doi.org/10.21776/ub.rjls.2021.008.01.4.
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Damping off disease in soybean plants is caused by the fungal Rhizoctonia solani. The damping off disease causes a yield loss of up to 85-100%. The purpose of this study was determining the ability chitinolytic bacteria consortium of UB Forest's in suppressing damping off disease in vitro and in vivo as well as its potential to stimulate the growth of soybean plants. The research stages included isolation of the pathogenic fungus R. solani and the pathogenicity test. Rejuvenation chitinolytic bacterial isolates of UB Forest, test chitinolytic bacteria antagonist of UB Forest against R. solani fungus, test of Plant Growth Promoting (PGP) activities, synergy test of selected chitinolytic bacterial isolates, in vitro test for the inhibition of chitinase crude extract against R. solani, and inhibition test of chitinolytic bacteria consortium against damping off disease. The selected chitinolytic bacteria were code bacteria UB12, UB19, and UB52 with plant growth promoting activities with inhibition percentage of the pathogen R. solani of 73.9%, 67.4%, and 71.7%. The best chitinolytic bacterial isolates were the genus Bacillus sp. and Pseudomonas sp. The inhibition test of chitinase crude extract showed an inhibition percentage of 25-55%.