Late blight of potato is one of the most destructive diseases of potato. This disease was also responsible for the Great Irish Potato Famine in Ireland which was begun in 1845 when fungi like organism Phytophthora infestans speared in the whole Ireland and the potato crop did not recover from this disease upto 1852. Potato used to be one of the most staple food crops of Irish people at that time and they were used to take potato in every meal. As a result of this great famine, over one million people died of hunger and 2 million people emigrated from Ireland to South America and Great Britain to escape the starvation and poverty.
Diagnostic symptoms
Symptoms first appear as water-soaked spots, usually at the edge lower surface of the leaves. During humid conditions when relative humidity reaches above 90 % and temperature ranges from 8-22 oC, Phytophthora infestans produces sporangia and sporangiophores on the infected tissues of stem and leaves. This sporulation results in visible white growth on lesions. The plant can be killed within a week after first symptom appearance by this pathogen. This pathogen also infects tuber which can serve as primary source of inoculum.
Management
1. Use pathogen free potato seeds for planting.
2. Adopt cultural practices like crop rotation as this pathogen can also survive in soil in the form of oospores, field sanitation and crop residue management.
3. Grow resistant varieties like Kufri Giriraj, K. Giridhari, K. Sherpa, K. Swarna and K. Badshah.
4. Give prophylactic spray of Mancozeb @ 0.2 % and Copper oxychloride @ 0.3 %.
5. If attack is early in season give one spray of Ridomil @ 0.2%.
Tags
Irish Famine
Great Irish Potato Famine in Ireland
Irish Famine
Irish Famine
Bangal Famine
Bangal Famine
