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Early Blight & Late Blight | Different Symptoms and causes

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Early blight and late blight are the most common diseases on tomato & potato. They usually take huge losses to farmers. Although the names of the two diseases are the only one-word difference, some growers do not know exactly about the difference between early blight and late blight.

First, we need to how to recognize their symptoms.

Difference between Early blight & Late blight

Causes

Early blight is caused by two different closely related fungi, Alternaria tomatophila, and Alternaria solani, which lives in soil and plant debris.

Late blight is caused by Phytophthora infestans, a microorganism which prefer moist and cool environments.


Conditions

Early blight

A suitable temperature is 24~29°C, relative humidity is 31~96%, which is warm and humid weather.

Late blight

The optimum humidity for sporangia germination to form zoospores is to reach saturation when there are water droplets.

The optimum temperature is 12~15°C.

Above 15°C, sporangia directly invade the host, but it takes a l…