scholarly journals Management of Gray Mold of Iceberg Lettuce by Biological Control Agents and Chitosan Formulations

2019 ◽  
pp. 1-7
Author(s):  
R. G. A. S. Rajapakse ◽  
M. P. T. Premarathna ◽  
Shyamalee Kohombange ◽  
D. G. N. S. B. Jayasinghe ◽  
H. A. S. Rohana ◽  
...  
Keyword(s):  
Biological Control ◽  
Gray Mold ◽  
Causal Agent ◽  
In Vitro Test ◽  
Trichoderma Asperellum ◽  
Biological Control Agents ◽  
Liquid Formulation ◽  
Fluorescent Pseudomonas ◽  
Iceberg Lettuce ◽  
Fresh Vegetables

Gray mold caused by Botrytis is the major problem in iceberg lettuce cultivation in poly tunnels in Sri Lanka. Currently management of this disease of lettuce depends mainly on foliar application of fungicides. Continues application of fungicides for control of gray mold could not be recommended as lettuce mainly consume as fresh vegetables. Therefore, studies were conducted to identify the causal agent, varietal resistance to pathogen and effective chitosan formulation and biological control agents on control of gray mold diseases of ice berg lettuce in poly tunnels. Causal agent of this disease was identified as Botrytis cinerea. Commercially grown varieties Eden and Maruli were equally susceptible to the disease. Different isolates of pathogen were shown different virulence levels on iceberg lettuce variety Eden. In vitro test showed that, almost complete inhibition of mycelia growth of all Botrytis isolates at 600 ppm chitopower 2 and liquid formulation of Trichoderma asperellum (4x105 conidia/ml) but 600 ppm chitopower 1 or liquid formulation of fluorescent Pseudomonas (106 bacteria/ml) or fungicide-Dicloran 75WP (3000ppm) were suppressed some isolates only. Studies in poly tunnel showed that lowest disease severity index (3.6% DSI) of gray mold in iceberg lettuce plants treated with Trichoderma asperellum and highest DSI (77.7%) in control treatment. Dicloran 75WP, chitopower 2 and fluorescent Pseudomonas were recorded 16.6%, 18.5% and 46.2% DSI respectively. Results revealed that Trichoderma asperellum bio control agent and chitopower 2 could be used as alternatives to synthetic fungicides in controlling of gray mold disease of iceberg lettuce grown in poly tunnels.

scholarly journals Isolation and Characterization of Endophyte Bacillus velezensis KOF112 from Grapevine Shoot Xylem as Biological Control Agent for Fungal Diseases

Plants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1815
Author(s):  
Kazuhiro Hamaoka ◽  
Yoshinao Aoki ◽  
Shunji Suzuki
Keyword(s):  
Biological Control ◽  
Downy Mildew ◽  
Biological Control Agent ◽  
Management Strategies ◽  
Gray Mold ◽  
Biological Control Agents ◽  
Bacillus Velezensis ◽  
Isolation And Characterization ◽  
Zoospore Release ◽  
Chemical Fungicides

As the use of chemical fungicides has raised environmental concerns, biological control agents have attracted interest as an alternative to chemical fungicides for plant-disease control. In this study, we attempted to explore biological control agents for three fungal phytopathogens causing downy mildew, gray mold, and ripe rot in grapevines, which are derived from shoot xylem of grapevines. KOF112, which was isolated from the Japanese indigenous wine grape Vitis sp. cv. Koshu, inhibited mycelial growth of Botrytis cinerea, Colletotrichum gloeosporioides, and Phytophthora infestans. The KOF112-inhibited mycelial tips were swollen or ruptured, suggesting that KOF112 produces antifungal substances. Analysis of the 16S rDNA sequence revealed that KOF112 is a strain of Bacillus velezensis. Comparative genome analysis indicated significant differences in the synthesis of non-ribosomal synthesized antimicrobial peptides and polyketides between KOF112 and the antagonistic B. velezensis FZB42. KOF112 showed biocontrol activities against gray mold caused by B. cinerea, anthracnose by C. gloeosporioides, and downy mildew by Plasmopara viticola. In the KOF112–P. viticola interaction, KOF112 inhibited zoospore release from P. viticola zoosporangia but not zoospore germination. In addition, KOF112 drastically upregulated the expression of genes encoding class IV chitinase and β-1,3-glucanase in grape leaves, suggesting that KOF112 also works as a biotic elicitor in grapevine. Because it is considered that endophytic KOF112 can colonize well in and/or on grapevine, KOF112 may contribute to pest-management strategies in viticulture and potentially reduce the frequency of chemical fungicide application.

scholarly journals KARAKTERISASI DAN UJI AKTIVITAS BAKTERI RIZOSFER LAHAN ULTISOL SEBAGAI PEMACU PERTUMBUHAN TANAMAN DAN AGENSIA HAYATI CENDAWAN PATOGEN TULAR TANAH SECARA IN VITRO

2010 ◽  
Vol 10 (2) ◽  
pp. 123-130
Author(s):  
Andi Khaeruni ◽  
Gusti Ayu Kade Sutariati ◽  
Sri Wahyuni
Keyword(s):  
Biological Control ◽  
Plant Growth ◽  
Plant Pathogens ◽  
Nitrogenase Activity ◽  
In Vitro Test ◽  
Biological Control Agents ◽  
Plant Growth Promoting ◽  
Vitro Test ◽  
Growth Promoting

Characterization and activities assay of rhizosphere bacteria from ultisol land for plant-growth promoting and biocontrol agents of soil-borne fungus pathogens under in vitro test.  Although many studies have been conducted to identify the specific traits of the plant growth-promoting and bioprotecting rhizobacteria (PGPBR), they were limited to studying specific PGPBR isolates from ultisol lands.  We selected 273 isolates from bulk soil and plant rhizosphere and examined them for a wide array traits that might inhibit the growth of plant pathogens and increase early cucumber growth in ultisol soil.  A subsample of 25 isolates, all positively produce chitinase and sellulose enzymes, 18 positively produce protease and 7 were fluorescens on KB medium under UV lighting.  All isolates could produce IAA and be able to solubilize phosphor in vitro test, 10 exhibited low level of nitrogenase activity. Futher test showed that out of 25 isolates, 12  inhibited F. oxysporum, P. capsici, R. solani and S. rolfsii in vitro.  All isolates increased seed germination, but only 5 isolates significanty increased early cucumber growth in ultisol soil. The results suggest that rhizobacteria be able to produce extracelluler enzymes, siderophore, ACC deasiminase, and IAA or those which are able to solubilize phosphor in vitro may be potential to be uses as biofertilizer and biological control agents in ultisol land.

Yellow Brazilian Pepper-tree Leaf Galler (suggested common name) Calophya latiforceps Burckhardt (Insecta: Hemiptera: Calophyidae: Calophyinae)

EDIS ◽  
2017 ◽  
Vol 2017 (6) ◽  
Author(s):  
James P. Cuda ◽  
Patricia Prade ◽  
Carey R. Minteer-Killian
Keyword(s):  
Biological Control ◽  
North America ◽  
Natural Enemies ◽  
Host Plants ◽  
Classical Biological Control ◽  
Biological Control Agents ◽  
Pepper Tree ◽  
Brazilian Pepper ◽  
Close Relatives ◽  
Tree Leaf

In the late 1970s, Brazilian peppertree, Schinus terebinthifolia Raddi (Sapindales: Anacardiaceae), was targeted for classical biological control in Florida because its invasive properties (see Host Plants) are consistent with escape from natural enemies (Williams 1954), and there are no native Schinus spp. in North America. The lack of native close relatives should minimize the risk of damage to non-target plants from introduced biological control agents (Pemberton 2000). [...]

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