Soil Solarization and Gliocladium virens Reduce the Incidence of Southern Blight Sclerotium rolfsii in Bell Pepper in the Field

This experiment was conducted to assess the effect of Trichoderma harzianum, soil solarization, and biofumigant on southern blight dis-ease of carrot incited by Sclerotium rolfsii isolate CS 5. A series of in-vitro and in-vivo trials laid out to select a virulent isolate of S. rolfsii against the carrot variety New Kuroda and evaluated the mustard, cabbage, cauliflower, and broccoli leaf extracts for choosing an effec-tive biofumigant against test pathogen. Mustard was the most effec-tive in inhibiting the radial growth, and sclerotia formation (80.37 and 83.37%) of S. rolfsii (isolate CS 5) at 40% level of concentration followed by cabbage leaf extract (62.22 and 68.69%). On the contrary, a total of 10 isolates of T. harzianum were screened against the test pathogen on Potato Dextrose Agar (PDA) medium for choosing a dominant isolate of T. harzianum. The isolate Th-6 was found as the most active in inhibiting the radial growth (84.44%) of S. rolfsii fol-lowed by Th-1 (75.56%). In the application of T. harzianum, biofumi-gation, and soil solarization, the treatment appeared to be the most superior in reducing pre- and post-emergence mortality of carrot during secondary field trials. The lowest southern blight disease inci-dence (10.77%), and disease severity (12.78%) were found at the same treatment. Subsequently, the yield of carrot was increased 155.18% which might be due to the reduction of carrot disease as well as the addition of organic materials in the soil.

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Management of southern blight of bell pepper by soil amendment with dry biomass of Datura metel

Journal of Plant Pathology ◽

10.1007/s42161-021-00874-6 ◽

2021 ◽

Author(s):

Nadia Jabeen ◽

Arshad Javaid ◽

Amna Shoaib ◽

Iqra Haider Khan

Keyword(s):

Soil Amendment ◽

Bell Pepper ◽

Southern Blight ◽

Datura Metel ◽

Dry Biomass

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Development of mutants of Gliocladium virens tolerant to benomyl

Canadian Journal of Microbiology ◽

10.1139/m90-084 ◽

1990 ◽

Vol 36 (7) ◽

pp. 484-489 ◽

Cited By ~ 12

Author(s):

G. C. Papavizas ◽

D. P. Roberts ◽

K. K. Kim

Keyword(s):

Carbon Source ◽

Type Strain ◽

Wild Type Strain ◽

Carbon Sources ◽

Sclerotium Rolfsii ◽

Wild Type ◽

Gliocladium Virens ◽

Rhizosphere Competence ◽

Filter Paper Cellulase ◽

Type Strains

Aqueous suspensions of conidia of Gliocladium virens strains Gl-3 and Gl-21 were exposed to both ultraviolet radiation and ethyl methanesulfonate. Two mutants of Gl-3 and three of Gl-21 were selected for tolerance to benomyl at 10 μg∙mL−1, as indicated by growth and conidial germination on benomyl-amended potato dextrose agar. The mutants differed considerably from their respective wild-type strains in appearance, growth habit, sporulation, carbon-source utilization, and enzyme activity profiles. Of 10 carbon sources tested, cellobiose, xylose, and xylan were the best for growth, galactose and glucose were intermediate, and arabinose, ribose, and rhamnose were poor sources of carbon. The wild-type strains and the mutants did not utilize cellulose as the sole carbon source for growth. Two benomyl-tolerant mutants of Gl-3 produced less cellulase (β-1,4-glucosidase, carboxymethylcellulase, filter-paper cellulase) than Gl-3. In contrast, mutants of Gl-21 produced more cellulase than the wild-type strain. Only Gl-3 provided control of blight on snapbean caused by Sclerotium rolfsii. Wild-type strain Gl-21 and all mutants from both strains were ineffective biocontrol agents. Key words: Gliocladium, benomyl tolerance, Sclerotium, rhizosphere competence.

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