FrogEye Leaf spot
Causal organism: Cercospora nicotianae.
Symptoms of FrogEye Leaf spot Tobacco
1. Small roundish spot are developed on the leaves, especially on the older leaves.
2. The spots enlarge and become roughly circular in shaped.
3. The centre of the spots turns white or pale brown surrounded by a dark black margin resembling the eye of a frog.
4. More than one lesion coalesce together to form a bigger lesions and maximum portion of leaves dry down and finally fallen it.
|Symptoms of FrogEye Leaf spot Tobacco|
Disease cycle of FrogEye Leaf spot Tobacco
The fungus may over winter in the crop residues, plant debris and on the collateral host. From this source, the air borne conidia because primary infection then favourable condition, it may cause secondary infection.
Favourable condition of FrogEye Leaf spot Tobacco
• Close plantation.
• Frequent irrigation/rainfall.
• High Relative humidity, above 80%.
• Excess use of nitrogenous fertilizer.
• Windy weather.
• Insect infestation.
• Present of wounds.
Control Measure/Management of FrogEye Leaf spot Tobacco
A. Cultural method
Cultural method is good for minimizing the disease;
v Optimum fertilizer management.
v Optimum irrigation as a when necessary.
v Weeding of collateral host.
v Sanitation of the field.
B. Chemical method
v Spraying Bordeaux mixture usually 2 times at 10-12 days interval.
v Spraying of fungicides like Macuprax, Cupravit, Dithane M45 @ 2% solution at 2-3 times onset of disease at 20 days interval.