PATHOGEN SYMPTOMS MANAGEMENT

1. FLAT LIMB OF SAPOTA
COLLEGE OF AGRICULTURAL TECHNOLOGY
(Affiliated to Tamil Nadu Agricultural University, Coimbatore-3)
Kullapuram (Po),ViaVaigai Dam, Theni-625 562
STUDENT
Miss. GOWSIKA M
ID. No. 2015021041
COURSE TEACHER
Dr. PARTHASARATHY S
Asst. Professor (Plant Pathology)

2. • Common name
Flat limb of sapota
• Local name
Flat leaf disease, Fasiciation disease,
Flattened disease.

3. HISTORY
• Bose and Metha (1951) recorded fasciated twigs and
mummified fruits of sapota in Uttar Pradesh and could
isolate the Pestalotia only.
• Flat limb in sapota was first reported from Maharastra
and Gujarat by Singh (1972).

4. SIGNIFICANCE
• It can cause yield loss up to 40% by limiting
the fruit bearing of infected twigs.

5. DISTRIBUTION
 World
Mexico, America.
 India
Maharastra, Gujarat, Tamil Nadu, Karnataka, West
Bengal and Andhra Pradesh.

6. CAUSAL ORGANISM
• Anamorph stage (asexual stage)
Botryodiplodia theobromae
• Telomorph (sexual stage)
Botryospheria rhodina

7. SYMPTOMS
• Branches of affected trees become flat and
twisted.
• Leaves become thin, small and yellow.
• Infested plant produces cluster of leaves and
flowers on the affected twigs.
• Flowers remain infertile.

8. • If fruits are set they are undersized , hard and fail
to ripen.
• Foliage and fruit fall prematurely.
• If cold dry condition prevailed more branches
developed symptoms, but hot weather delayed
symptom appearance.
• If the summer onset flat limb branches produced
round, normal looking branches.

9. Flattened twigs
© www.eurekamag.com

10. PATHOGEN
The fungi produces pycnidia. Young conidia are
hyaline thin walled and single celled.
Matured conidia are dark brown in colour and two
celled.
They were ovoid to elongated and round at end.

11. © www.tnauagriportal.com

12. SYSTEMATIC POSITION
Kingdom - Fungi
Division - Ascomycota
Class - Dothideomycetes
Order - Botryosphaeriales
Family - Botryosphariaceae
Genus - Botryodiplodia
Species - B. theobromae

13. FAVOURABLE CONDITIONS
 High humidity
 Temperature of 24°C – 32°C.
 Frequent rains.
 Moist conditions favours the development of
disease (October to November)

14. MODE OF INFECTION
 Primary spread
Through ascospore from perithecia.
 Secondary spread
Wind borne conidia

15. INTEGRATED DISEASE MANAGEMENT
Collection and destruction of infested twigs.
Pruning of affected branches followed by spraying of
captan or thiram 0.3%.
Spraying of 0.1% Mancozeb or Mancozeb and
Metalaxyl 0.1% helps to effectively control the
disease.

16. REFERENCES
https://eurekamag.com> research
https://www.yumpu.com
Chaube.H.S, V.S Pundhur, ‘Crop diseases and their
management’, fourth edition 2005 PHI Learning
Private Limited, New Delhi.
Harry Waren Anderson, ‘Diseases of fruits and
vegetable crops’ J.V Publishing house, Jothpur.