Difference Between Early Blight and Late Blight of Potato

The key difference between early blight and late blight of potato is that early blight of potato is a disease caused mainly by the fungus Alternaria solani while late blight of potato is a disease caused by the oomycete Phytophthora infestans.

Early blight and late blight are two diseases affecting Solanaceae vegetables. Both diseases are widely distributed. They are serious diseases commonly seen in potato and tomato, causing heavy losses for farmers. Alternaria tomatophila and Alternaria solani cause early blight in potato while Phytophthora infestans causes late blight of potato. Both diseases produce brown spots on leaves and stems.

CONTENTS

1. Overview and Key Difference
2. What is Early Blight of Potato
3. What is Late Blight of Potato
4. Similarities Between Early Blight and Late Blight of Potato
5. Side by Side Comparison – Early Blight vs Late Blight of Potato in Tabular Form
6. Summary

What is Early Blight of Potato?

Early blight of potato is a fungal disease seen on potatoes. It is caused by two different, but closely-related fungi: Alternaria tomatophila and Alternaria solani. These fungi live in soil and plant debris. They prefer to grow in warm and high humidity environments. Therefore, early blight in potato favours warm temperatures.

Late blight is an important disease since it causes serious damage to potato production. Small dark spots can be seen in the lower and older leaves of the plant when early blight disease occurs in potato.

What is Late Blight of Potato?

Late blight is one of the serious diseases seen in potato. It is caused by the microorganism Phytophthora infestans. Phytophthora infestans is an oomycete. This disease affects potato crops worldwide, causing serious economic losses. Hence, Phytophthora infestans is considered as the most important pathogen of potatoes. Moreover, it also infects tomatoes, just like potatoes. Late blight favours moist and cool weather conditions because Phytophthora infestans prefers to grow in moist and cool environments.

Late blight can cause the development of leaf rots or lesions. When the infection occurs at the seedling stage, it causes the seedlings to wilt or fold. At the adult stage, the stems become dark brown and rot-like while the leaves have water-soaked irregular lesions. Finally, large parts of the plant rot, eventually killing the plant.

What are the Similarities Between Early Blight and Late Blight of Potato?

• Early blight and late blight of potato are serious diseases which are widely distributed in the world.
• They cause huge damage to potato production.
• These two diseases are also seen in tomato and some other Solanaceae vegetables.
• Thought these diseases commonly appear in two different time periods, they can occur at the same time as well.

What is the Difference Between Early Blight and Late Blight of Potato?

Early blight of potato is caused by Alternaria solani. Meanwhile, late blight of potato is caused by Phytophthora infestans. So, the causative is the key difference between early blight and late blight of potato. Also, an early blight of potato is a fungal infection while late blight of potato is an oomycete infection. Thus, this is another difference between early blight and late blight of potato.

Moreover, the early blight of potato prefers warm temperatures and high humidity while the late blight of potato prefers cool, moist weather. This is also an important difference between early blight and late blight of potato.

Summary – Early Blight vs Late Blight of Potato

Early blight and late blight of potato are two widely distributed diseases. Both diseases are responsible for huge economic losses. Alternaria solani is the main causative fungus of early blight of potato. In contrast, Phytophthora infestans is the main causative agent of late blight in potato. So, this is the key difference between early blight and late blight of potato. Moreover, warm temperatures and high humidity favour early blight of potato while cool and moist weather favour late blight of potato. Both diseases produce brown spots on leaves and stems.

Reference:

1.“Integrated Pest Management.” Early Blight and Late Blight of Potato – CT Integrated Pest Management Program, Available here.
2. Shin, Malcolm. Phytophthora Infestans, Available here.

Image Courtesy:

1. “Early blight on tomato leaves (7871930010)” By Dwight Sipler from Stow, MA, USA – Early blight on tomato leavesUploaded by Jacopo Werther (CC BY 2.0) via Commons Wikimedia
2. “Phytophtora infestans-effects” (Public Domain) via Commons Wikimedia