Curvularia lunata as new causal pathogen of tomato early blight disease in Egypt

Abstract Tomato plants displaying early blight symptoms were collected from different localities in the provinces of Assiut and Sohag, Egypt. The causal pathogens were isolated on potato dextrose agar plates. Pathogenicity tests with 48 isolates were carried out under greenhouse conditions on tomato cultivar (CV 844). All tested isolates caused symptoms of early blight disease with different degrees. The highest disease severity on tomato plants was found after inoculation with isolate No. 6 followed by isolates No. 20 and No. 31. The most pathogenic isolates were identified by sequence analysis using ITS1 and ITS4 primers. The analysis of the amplified sequences from fungal isolates No. 6, 20 and 31 displayed 99 - 100% nucleotide identity with Alternaria solani, Curvularia lunata and A. alternata, respectively. To our knowledge, this is the first report of Curvularia lunata as one of the causal pathogens of early blight disease of tomato plants in Egypt.

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Efficacy of some conventional fungicides and essential oils against tomato early blight disease

World Journal of Advanced Research and Reviews ◽

10.30574/wjarr.2021.10.1.0103 ◽

2021 ◽

Vol 10 (1) ◽

pp. 094-104

Author(s):

Ahmed S. Abdel–Aty ◽

Elsayed A.M. Abdallah ◽

Ezzat A. kaduos ◽

Mohamed R. A. Gad

Keyword(s):

Early Blight ◽

Phenol Oxidase ◽

Plant Oils ◽

Garlic Mustard ◽

Tomato Plants ◽

Bitter Almond ◽

Causal Pathogen ◽

Blight Disease ◽

Main Components

Fungicidal activity of nine selected conventional fungicides, identified five plant oils and their combined effect against A. solani, the causal pathogen of early blight on tomato. GC-MS analysis of the tested oils indicated that terpene hydrocarbons (97%) with cinnamaldehyde as the major compound; sulfur compounds; fatty acids and organo-sulfur-containing compounds were the main components in cinnamon, garlic, mustard and onion oils, respectively. In vitro, Speedcide® (difenoconazole) and Cabrioduo® (Dimethomorph + Pyraclostrobin) were the most effective against the A. solani fungus with EC50 values of 94.6 and 88.6 ppm respectively. Toledo® (Tebuconzole) achieved EC50 value of 631.2 ppm. Roxyl-M® was significantly more effective than Roxyl–plus® or Remik®. Speedcide® alone or mixed with mandipropamid or azoxystrobin in Revus-Top® or Cruze® were the lowest effective in vitro. Garlic and mustard oils were more effective in liquid media than solid one. Cinnamon, onion, garlic and bitter almond oils caused moderate fungi-toxicity against early blight pathogen and could be implemented in the IPM program. Lower EC50 values were obtained in case of combinations of fungicides with oils than separate treatments. Effect of the active conventional fungicides and plant oils on disease indices, relative disease control, chlorophyll content, sugar contents and poly phenol oxidase in tomato plants was also studied.

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Induction of defense mechanisms from filtrates of saprophytic fungi against early blight disease in tomato

African Journal of Microbiology Research ◽

10.5897/ajmr2016.8106 ◽

2016 ◽

Vol 10 (44) ◽

pp. 1849-1859 ◽

Cited By ~ 2

Author(s):

Jussiê da Silva Solino Antônio ◽

Regina Freitas Schwan-Estrada Kátia ◽

Santos Batista Oliveira Juliana ◽

dos Santos Rodrigues Alencar Marianna ◽

Martins Ribeiro Lilianne

Keyword(s):

Defense Mechanisms ◽

Early Blight ◽

Saprophytic Fungi ◽

Blight Disease

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Evaluation of various plant extracts against the early blight disease of tomato plants under greenhouse and field conditions

Plant Protection Science ◽

10.17221/14/2011-pps ◽

2012 ◽

Vol 48 (No. 2) ◽

pp. 74-79 ◽

Cited By ~ 19

Author(s):

S.M.A. Nashwa ◽

K.A.M. Abo-Elyousr

Keyword(s):

Disease Severity ◽

Plant Extracts ◽

Mycelial Growth ◽

Early Blight ◽

Field Conditions ◽

Nerium Oleander ◽

Tomato Plants ◽

Infected Control ◽

Blight Disease

The antimicrobial activity of six plant extracts from Ocimum basilicum (Sweat Basil), Azadirachta indica (Neem), Eucalyptus chamadulonsis (Eucalyptus), Datura stramonium (Jimsonweed), Nerium oleander (Oleander), and Allium sativum (Garlic) was tested for controlling Alternaria solani in vitro and in vivo. In in vitro study the leaf extracts of D. stramonium, A. indica, and A. sativum at 5% concentration caused the highest reduction of mycelial growth of A. solani (44.4, 43.3 and 42.2%, respectively), while O. basilicum at 1% and 5% concentration and N. oleander at 5% concentration caused the lowest inhibition of mycelial growth of the pathogen. In greenhouse experiments the highest reduction of disease severity was achieved by the extracts of A. sativum at 5% concentration and D. stramonium at 1% and 5% concentration. The greatest reduction of disease severity was achieved by A. sativum at 5% concentration and the smallest reduction was obtained when tomato plants were treated with O. basilicum at 1% and 5% concentration (46.1 and 45.2 %, respectively). D. stramonium and A. sativum at 5% concentration increased the fruit yield by 76.2% and 66.7% compared to the infected control. All treatments with plant extracts significantly reduced the early blight disease as well as increased the yield of tomato compared to the infected control under field conditions.

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