scholarly journals Biological Control of Powdery Mildew on Zinnia (Zinnia elegans, L) Using Some Biocontrol Agents and Plant Extracts

2010 ◽  
Vol 2 (4) ◽  
Author(s):  
Mahmoud Abdelnabi Hegazi ◽  
Gabr Abdelwanes El-Kot
Keyword(s):  
Biological Control ◽  
Powdery Mildew ◽  
Plant Extracts ◽  
Zinnia Elegans ◽  
Biocontrol Agents

Biological control of postharvest fungal rots of rosaceous fruits using microbial antagonists and plant extracts - a review.

2016 ◽  
Vol 68 (1) ◽  
pp. 41-66 ◽  
Author(s):  
Shazia Parveen ◽  
Abdul Hamid Wani ◽  
Mohd Yaqub Bhat ◽  
Jahangir Abdullah Koka
Keyword(s):  
Biological Control ◽  
Plant Extracts

scholarly journals Effect of Plant Extracts and Biological control agents on Rhizoctonia solani Kuhn

2021 ◽  
Vol 735 (1) ◽  
pp. 012079
Author(s):  
Muneer Saeed M. Al-Baldawy ◽  
Ahed A A H Matloob ◽  
Mohammed K. N. Almammory
Keyword(s):  
Biological Control ◽  
Rhizoctonia Solani ◽  
Plant Extracts ◽  
Biological Control Agents

scholarly journals Biological control of Podosphaera xanthii the causal agent of squash powdery mildew disease by upregulation of defense-related enzymes

2018 ◽  
Vol 28 (1) ◽  
Author(s):  
Yaser M. Hafez ◽  
Asmaa S. El-Nagar ◽  
Abdelnaser A. Elzaawely ◽  
Said Kamel ◽  
Hanafey F. Maswada
Keyword(s):  
Biological Control ◽  
Powdery Mildew ◽  
Causal Agent ◽  
Podosphaera Xanthii ◽  
Powdery Mildew Disease

scholarly journals First Report of Podosphaera xanthii Causing Powdery Mildew on Zinnia elegans in Taiwan

Plant Disease ◽  
2020 ◽  
Author(s):  
Yi-Ting Xiao ◽  
Yuan-Min Shen ◽  
Chao-Jen Wang ◽  
Tung-Ching Huang
Keyword(s):  
Powdery Mildew ◽  
Average Length ◽  
Zinnia Elegans ◽  
Flowering Plant ◽  
Tween 20 ◽  
Width Ratio ◽  
Podosphaera Xanthii ◽  
Bedding Plants ◽  
Taichung City ◽  
Voucher Specimens

Zinnia elegans L., known as common zinnia, is an annual flowering plant belonging to the Asteraceae family and native to North America. The plant has colorful flowers and is one of the popular ornamental bedding plants for gardening. In March 2020, powdery mildew symptoms were observed in a zinnia floral field with an incidence of >70% in Dacun Township, Changhua County, Taiwan. The symptoms were spotted on the stems, flower petals and leaves which appeared as irregular colonies and white patches on the surfaces. When disease progressed, most of the plant surfaces were covered by the white fungal colonies and became yellowish. Under microscopic examination, hyphal appressoria of the fungus were indistinct or slightly nipple-shaped. The conidiophores were unbranched, erect, straight, smooth to slightly rough, 75.0 to 200.0 × 10.0 to 15.0 µm (n=10), composed of a cylindrical, flexuous foot cell, 40.0 to 100.0 × 8.8 to 15.0 µm (n=10), and following 1 to 5 shorter cells. The conidia were ellipsoid to ovoid, 25.0 to 37.5 × 15.0 to 23.8 µm (n=60), with an average length-to-width ratio of 1.8 and contained fibrosin bodies. No chasmothecia were found. Three voucher specimens (TNM Nos. F0033680, F0033681, and F0033682) were deposited in the National Museum of Natural Science, Taichung City, Taiwan. To confirm the identification, the internal transcribed spacer (ITS) regions of the three specimens were amplified using primer pairs ITS1/PM6 and PM5/ITS4 (Shen et al. 2015) and sequenced from both ends. The resulting sequences were deposited in GenBank under Accession Nos. MT568609, MT568610, and MT568611. The sequences were identical to each other and shared a 100% identity with that of Podosphaera xanthii MUMH 338 on Z. elegans from Japan (Accession No. AB040355) (Ito and Takamatsu 2010) over a 475 bp alignment. Accordingly, the fungus was identified as P. xanthii (Castagne) U. Braun & Shishkoff (Braun and Cook 2012) based on its morphological and molecular characters. Pathogenicity was demonstrated through inoculation by gently pressing naturally infected leaves onto leaves of three healthy potted common zinnia that had been sprayed with 0.02% Tween 20. Additional three non-inoculated plants treated in the same way without inoculating the powdery mildew served as the controls. Powdery mildew colonies were observed on inoculated leaves after 10 days at room temperature, later the diseased leaves became yellowish and deteriorated. The morphological traits of the fungus on the inoculated leaves were similar to those of the first observed. In addition, the ITS sequence from a colony on the inoculated leaves was 100% identical to MT568609-MT568611, fulfilling the Koch’s postulates. All the controls remained symptomless. Z. elegans is known to be a host for different species of powdery mildew in the genus Erysiphe, Golovinomyces, and Podosphaera (Farr and Rossman 2020). In Taiwan, powdery mildew has been briefly reported on zinnia without detailed descriptions (Hsieh 1983). This study confirmed P. xanthii as a causal agent of powdery mildew in Taiwan and the awareness of the disease may benefit the floral industry. To our knowledge, this is the first confirmed report of P. xanthii on Z. elegans in Taiwan.

Identification of Aspergillus flavus Isolates as Potential Biocontrol Agents of Aflatoxin Contamination in Crops

2013 ◽  
Vol 76 (6) ◽  
pp. 1051-1055 ◽  
Author(s):  
L. J. ROSADA ◽  
J. R. SANT'ANNA ◽  
C. C. S. FRANCO ◽  
G. N. M. ESQUISSATO ◽  
P. A. S. R. SANTOS ◽  
...  
Keyword(s):  
Biological Control ◽  
Aspergillus Flavus ◽  
Filamentous Fungus ◽  
Microscopic Examination ◽  
Genetic Recombination ◽  
Aflatoxin Contamination ◽  
Biocontrol Agents ◽  
Biological Control Agents ◽  
Nit Mutants ◽  
The Stability

Aspergillus flavus, a haploid organism found worldwide in a variety of crops, including maize, cottonseed, almond, pistachio, and peanut, causes substantial and recurrent worldwide economic liabilities. This filamentous fungus produces aflatoxins (AFLs) B1 and B2, which are among the most carcinogenic compounds from nature, acutely hepatotoxic and immunosuppressive. Recent efforts to reduce AFL contamination in crops have focused on the use of nonaflatoxigenic A. flavus strains as biological control agents. Such agents are applied to soil to competitively exclude native AFL strains from crops and thereby reduce AFL contamination. Because the possibility of genetic recombination in A. flavus could influence the stability of biocontrol strains with the production of novel AFL phenotypes, this article assesses the diversity of vegetative compatibility reactions in isolates of A. flavus to identify heterokaryon self-incompatible (HSI) strains among nonaflatoxigenic isolates, which would be used as biological controls of AFL contamination in crops. Nitrate nonutilizing (nit) mutants were recovered from 25 A. flavus isolates, and based on vegetative complementation between nit mutants and on the microscopic examination of the number of hyphal fusions, five nonaflatoxigenic (6, 7, 9 to 11) and two nontoxigenic (8 and 12) isolates of A. flavus were phenotypically characterized as HSI. Because the number of hyphal fusions is reduced in HSI strains, impairing both heterokaryon formation and the genetic exchanges with aflatoxigenic strains, the HSI isolates characterized here, especially isolates 8 and 12, are potential agents for reducing AFL contamination in crops.

NEW ASSOCIATIONS IN BIOLOGICAL CONTROL: THEORY AND PRACTICE

1989 ◽  
Vol 121 (10) ◽  
pp. 829-840 ◽  
Author(s):  
Heikki M.T. Hokkanen ◽  
David Pimentel
Keyword(s):  
Biological Control ◽  
Pest Control ◽  
Environmental Risks ◽  
Theory And Practice ◽  
Biocontrol Agents ◽  
Biological Control Agents ◽  
Biological Pest Control ◽  
New Associations ◽  
Future Success ◽  
New Association

AbstractThe new association approach for selecting biological control agents has been reanalyzed in the light of recent data. The results support the conclusion that the new association approach is ecologically and statistically sound. One of the major advantages of this approach is its capacity to control native pests, which make up 60–80% of all pests. The specificity of biocontrol agents newly associated with the target hosts is similar to other biocontrol agents. In addition, the new association approach is as safe as the old association approach in terms of environmental risks. Recent trials in the use of new associations have been most encouraging, and suggest that this approach should contribute to the future success of biological pest control worldwide.

scholarly journals First Screening of Entomopathogenic Nematodes and Fungus as Biocontrol Agents against an Emerging Pest of Sugarcane, Cacosceles newmannii (Coleoptera: Cerambycidae)

Insects ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 117 ◽  
Author(s):  
Marion Javal ◽  
John S. Terblanche ◽  
Desmond E. Conlong ◽  
Antoinette P. Malan
Keyword(s):  
South Africa ◽  
Biological Control ◽  
Chemical Control ◽  
Entomopathogenic Nematodes ◽  
Biocontrol Agents ◽  
Sugar Production ◽  
Biological Control Agents ◽  
Sugarcane Stalk ◽  
Reduce Sugar ◽  
Steinernema Yirgalemense

Cacosceles newmannii (Coleoptera: Cerambycidae) is an emerging pest of sugarcane in South Africa. The larvae of this cerambycid beetle live within the sugarcane stalk and drill galleries that considerably reduce sugar production. To provide an alternative to chemical control, entomopathogenic nematodes and fungus were investigated as potential biological control agents to be used in an integrated pest management system. The nematodes Steinernema yirgalemense, S. jeffreyense, Heterorhabditis indica, and different concentrations of the fungus Metarhizium pinghaense were screened for efficacy (i.e., mortality rate) against larvae of C. newmannii. The different biocontrol agents used, revealed a low level of pathogenicity to C. newmannii larvae, when compared to control treatments.

Biological control of powdery mildew on Cornus florida using endophytic Bacillus thuringiensis

2019 ◽  
Vol 42 (2) ◽  
pp. 182-191 ◽  
Author(s):  
Emily Rotich ◽  
Margaret T. Mmbaga ◽  
Jacqueline Joshua
Keyword(s):  
Biological Control ◽  
Bacillus Thuringiensis ◽  
Powdery Mildew ◽  
Cornus Florida
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