Target Spot of Potato, Tomato and Capsicum

Alternaria solani

Names:

Black Spot of Capsicum
Early Blight of Tomatoes
Early Blight of Potatoes

Description:

A fungal disease causing dark brown to black spots usually with a series of concentric rings on leaves. The spot may merge to kill large areas of the leaf.

Potato.

The spots are angular, up to 20 mm wide and look leathery.
Round sunken pits develop and may merge to cause large sunken patches.

Tomato.

The spots on leaves are usually 6-12 mm diameter, somewhat oval and often with a yellow halo. On stems the lesions are elongated with obvious lines. On fruit the dark brown to black, sunken and concentrically lined or ringed lesion usually occurs near the stalk and causes rotting of one side of the fruit and extends into the heart. Tomato seedling may be killed when they are attacked near ground level.

Species Affected:

Capsicum, Eggplant, Nightshades, Potato, Tomato and other Solanaceous species.

Biology:

Favoured by warm moist weather.
Seed borne.
Spores from leaf spots are spread by wind, rain and insects.
Survives on plant debris for over a year.

Life Cycle:

Origin and History:

Distribution:

Significance:

Management and Control:

Plant healthy seed.
Remove and destroy infected plants, and weeds.
Keep crop growing vigorously.
Destroy infected crop residues.
Rotate with resistant crops.
Don't plant a susceptible crop for at least 3 years after the last susceptible crop.
Apply fungicides.

Capsicums and Tomatoes

Use clean seed.

Potatoes

Apply fungicides.

Related and Similar Species:

References:

Acknowledgments:

Collated by HerbiGuide. Phone 08 98444064 or www.HerbiGuide.com.au for more information.