Plant pathology

1. COLLEGE OF AGRICULTURAL TECHNOLOGY
(Affiliated to Tamil Nadu Agricultural University, Coimbatore-3)
Kullapuram (Po),ViaVaigai Dam, Theni-625 562
CARDAMOM DAMPING OFF
Student Course teacher
A.Hariharan Dr.Parthasarathy.S
2015021043 Assistant Professor (Plant Pathology)

2. Name of disease
• Common name:cardamom damping off-Pythium vexans
• Other names: soft rot and Rihzome rot-Rhizoctonia solani

3. History of disease
 Rhizome rot is a common disease occurring in cardamom
plantations during monsoon period.
 The disease was first reported by Park (1937). Subba Rao
(1938) described it as clump rot disease.
 The disease is widely distributed through out cardamom plantation.

4. Occurance
• World:
Indonesia,hong kong ,malaysia,singapore,pakistan india and
sri lanka.
• India:
karnataka,kerala, tamil nadu.
Inventor: Siddaramaiah (1988).

5. Economic importances
 Rhizome rot is one of the earliest noticed fungal disease .
 the incidence of the disease in cardamom hills of Kerala.
 occurring in Kerala and Karnataka, and is also called as clump rot
disease (Mayne 1942).

6. SYSTEMATIC POSITION
Kingdom:Chomista
Phylum:Oomycota
Class:Oomycetes
Order:Pythiales
Family:Pythiaceae
Genus:Pythium
Species:Pythium vexans

7. Life cycle-Sexual reproduction

8. Asexual reprodution

9. Symptoms
• Leaves turn pale and their tips become yellow. Gradually, these symptoms spread
over the entire leaf extending to leaf sheath resulting in wilting of seedlings.
• The collar portion decays and the entire seedlings die. Infection spreads in the
nursery beds resulting in death of seedlings in small patches.
• In grown up seedlings, rotting extends from the collar region to the rhizomes
resulting in their decay and ultimate death of the plant

10. Symptoms

11. Survival and spread
• It spreads to rhizomes and roots.
• Seed, soil and Water.

12. Favourable conditions
• High humidity, high soil moisture, cloudiness and low temperatures below 24° C
for few days are ideal for infection and development of disease.
• Crowded seedlings, dampness due to high rainfall, poor drainage and excess of
soil solutes hamper plant growth and increase the pathogenic damping-off.
• Cool and moist conditions due to rain or show at higher elevation .

13. Management
 Destruction of diseased clumps and Provide proper drainage
 changing the nursery site and Avoid crowding
 Soil drenching with one percent Bordeaux mixture or 0.25 percent copper
oxychloride at one-month interval has been reported to be very effective for
controlling the disease .
 Pre-treatment of nursery beds with fomaldehyde (0.2%).fungicides such as
Mancozeb and Brassicol (PCNB) were effective for disease control.

14. Reference
• Joseph, T., Suseela Bhai, R.and Naidu, R.,(1991). Capsule rot disease
of cardamom and its control. J. Plantn. Crops (Suppl.) 18: 264-268.
• Ramakrishnan, T.S. (1949). The occurrence of Pythium vexons de
Bary in South India. Indian Phytopath. 2: 27-30.