Alka Kumari is presenting a seminar on late blight of potato to Dr. Meenakshi Singh. The seminar will cover the history, causal organism, symptoms, mode of spread, favorable conditions, and life cycle of the potato late blight pathogen Phytophthora infestans. It will also discuss control measures such as using resistant potato varieties, avoiding bruising of tubers during harvest, and regularly spraying fungicides like Brestan, Zineb, Bordeaux mixture, and Mancozeb.

1. PATNA UNIVERSITY
DEPARTMENT OF BOTANY
A SEMINAR PRESENTATION ON
“LATE BLIGHT OF POTATO”
SUBMITTED TO: SUBMITTED BY:
Dr. MEENAKSHI SINGH ALKA KUMARI
HOD, DEPARTMENT OF BOTANY ROLL NO.- 04
PATNA UNIVERSITY M.Sc. BOTANY
SEMESTER –I
SESSION: 2020-22

2. HISTORY
•Responsible for Irish Famine in
early 1840s.
•It has been reported in USA,
European countries, Canada,
Africa etc.
•The pathogen was first
described by M.J.
Berkeley(1846) and
subsequently named
Phytophthora infestans by
Anton de Bary(1876).

3. CAUSAL ORGANISM
• Phytophthora infestans , a group of organisms
sometime referred to as the “water molds”.
• Systematic Position
Kingdom Mycota
Division Eumycota
Sub-division Mastigomycotina
Class Oomycetes
Order Peronosporales
Family Pythiaceae
Genus Phytophthora
Species infestans

4. SYMPTOMS
• Water soaked spots appear
on leaves, turn purple brown
and finally black.
• Purplish brown spots on
tubers
• Tuber show rusty brown
necrosis spreading from surface
to the center.
• Light brown lesions develop
on stem which elongates.

5. MODE OF SPREAD
•Primary spread: The infected seed tubers
•Secondary spread: Rain splash and wind
FAVOURABLE CONDITION
• Cool( 12-15°C) and humid weather with rains
alternating with warm moist period.

6. LIFE CYCLE

7. CONTROL MEASURES
• Use resistant varieties- Kufri Naveen, Kufri
Jeevan, Kufri Alenker, Kufri Moti.
• Bruising of tubers at harvest should be avoided.
• Regular spraying during growing season gives
effective control-
 Brestan 600g/ha
 Zineb 0.2%
 Bordeaux mixture 1.0%
 Mancozeb (2Kg/ha)