Diseases like blight, blight, rot, mildew etc. of crop plants are caused by fungi.
(i) Helminthosporium oryzae fungus causes white or brown spot disease of rice. Due to this disease in 1942 there was a famine in then Bengal. The fungus Pyricularia oryzae causes blast disease of rice.
(ii) Phytophthora infestans fungus causes late blight of potato. The disease caused a famine in Ireland in 1843-47 and killed one million people. The fungus Alternaria solani causes early blight disease of potato.
(iii) Rust disease of wheat is caused by the fungus Puccinia graminis tritici. The fungus Erysiphe graminis tritici causes powdery mildew disease of wheat.
(iv) Peter the Great invaded Türkiye in 1722. There, hundreds of his horses were paralyzed and many died after eating argot-infested rye.
(v) Red rot disease of sugarcane is caused by the fungus Colletotrichum falcatum.
(vi) The fungus Exobasidium vexans causes blight disease of tea.