Correct option is D
The correct answer is (d).
Mycosphaerella fijiensis, the causal agent of Black Sigatoka disease in bananas, has the most prolonged symptomless infection phase among the listed pathogens. This pathogen can infect plants and remain in a symptomless or latent state for extended periods before causing visible symptoms, making it particularly challenging to control. It often remains hidden in infected tissue for a long time, only revealing symptoms when conditions are favorable for its growth.
Incorrect option-
Option (a) is incorrect because Phytophthora infestans causes late blight with a short incubation period; symptoms such as leaf blight appear quickly.
Option (b) is incorrect because Magnaporthe oryzae is the causal agent of rice blast disease, symptoms develop rapidly, making it easier to identify early infections.
Option (c) is incorrect because Botrytis cinerea is known as grey mold, it rapidly produces visible necrotic spots on many hosts shortly after infection.
