1. The causal organism of coconut bud rot is Phytophthora palmivora, an oomycete fungus. (2) Coconut bud rot was first reported in 1834 in the West Indies and has since been reported worldwide in coconut growing regions. (3) In India, coconut bud rot is widely prevalent along the east and west coasts, affecting states like Tamil Nadu.

1. COLLEGE OF AGRICULTURAL TECHNOLOGY
(Affiliated to Tamil Nadu Agricultural University, Coimbatore-3)
Kullapuram (Po), Via Vaigai Dam, Theni-625 562
COCONUT BUD ROT
Student: Course Teacher:
I.Gayathri Dr. Parthasarathy .S
2015021036 Asst. Prof., Plant Pathology.

2. COCONUT BUD ROT
Causal Organism:
Phytophthora palmivora (Butler)

3. HISTORY
• The first report of bud- rot incidence was from Grand
Cayman, an island in the West Indies, in 1834 ( Tucker
1926 ).
• Since then Quillec et al. (1984) reported the incidence
from Sri Lanka, Indonesia, the Philippines, Colombia,
PapuaNew Guinea, Vanuatu, Fiji, French Polynesia and
the Dominican Republic.

4. • Butler was the first to identify the disease in 1907
and he named the pathogen as Pythium palmivora but
later transferred it to genus Phytophthora.
• In 1996, heavy incidence of bud rot disease was
reported from Kuttiadi, in Kerala, leading to the
destruction of thousands of coconut palms in that
particular region.

5. Worldwide :The disease is reported wherever coconuts are
grown. It is recorded on coconut from Cook islands,
Fiji, Papua New Guinea, Samoa, Tonga and
Vanuatu.
India :The disease is widely prevalent in East and West
coasts of India. In Tamil Nadu the disease is
found in Chengalpattu, Coimbatore, Cuddalore,
Villupuram and Vellore districts.
DISTRIBUTION

6. Systematic Position – Phytophthora palmivora
Kingdom : Fungi
Phylum : Heterokontophyta
Class : Oomycota
Order : Peronosporales
Family : Peronosporaceae
Genus : Phytophthora
Species : P. palmivora

7. Pathogen and its characters
• The fungus produces intercellular, non septate, hyaline
mycellium.
• Sporangiophores are hyaline and simple or branched
occasionally.
• The sporangia are hyaline, thin walled, pear shaped with a
prominent papillae. Sporangia releases reniform, biflagellate
zoospores upon germination.
• The fungus also produces thick walled, spherical oospores. In
addition, thickwalled, yellowish brown chlamydospores are
also produced.

8. Favourable conditions
• High rainfall, high atmospheric humidity (above 90
percent), low temperature (18-20oC) and wounds
caused by tappers and Rhinoceros beetles (Oryctus
rhinoceros)

9. Mode of Spread and Survival
• The fungus remains as dormant mycelium in the infected
tissues and also survives as chlamydospores and oospores
in crop residues in the soil.
• The disease spread is mainly through air-borne sporangia
and zoospores.
• Rainfall also helps in spreading the disease.
• Insects and tappers also help in the spread of the
inoculum from diseased trees.

10. Symptoms
• The earlier symptom is the yellowing of one or two
younger leaves. Black spots appear on spindle
leaves. Basal tissues of the leaf rots quickly and can be
easily separated from the crown.
• In the later stages the spindle withers and drops down.
• The tender leaf base and soft tissues of the crown will rot
into a slimy mass of decayed material emitting foul smell.

11. • Ultimately the entire crown falls down and the palm dies.
• In adult palms, the first visible symptom is the colour
change of the spear, which becomes pale and breaks at the
base and hangs down. The rotting slowly progresses
downwards, finally affecting the meristem and killing the
palms. This is accompanied by drooping of successive
leaves. Even then, nuts that are retained on the palm may
grow to maturity.

12. Pale leaf Leaf rot

13. Rotting of basal tissue Drooping

14. Integrated Disease Management
Cultural control
• Provide adequate drainage in gardens, good drainage
lowers the humidity in the plantation and reduces leaf
wetness, which is needed for spore germination.
• Cut down and burn affected trees , as soon as the
disease is seen.

15. • Plant palms atleast 10 m apart; wide spacing allows
air movement through the plantation, and reduces the
leaf wetness.

16. Resistant varieties
• Malayan yellow and red dwarf varieties are
susceptible to bud rot, but hybrids with dwarf and tall
parents are less so.
• The Polynesian Tall and Rennell Tall are said to have
good tolerance.

17. Chemical Method
• Remove all the affected tissue of the crown region
and crown drenching with Copper oxychloride
0.25%. Apply Bordeaux paste and protect it from rain
till normal shoot emerges. (Dissolve 100 gm of
copper sulphate and 100 gm of quick lime each in
500ml water separately and mix to form 1 litre of
Bordeaux paste).

18. • The infected tissues from the crown region should be
removed and dressed with Bordeaux paste sprayed with
1% Bordeaux mixture as pre-monsoon spray (May and
September).
• Leaf axil filling with Sevidol 8G, 25 g mixed with 200g
sand is recommended to red palm weevil infestation of
affected palms.
• Spray with Copper oxychloride 0.25% after the onset of
Monsoon.

19. REFERENCES
• V.K.Gupta, Y.S.Paul, Satish K. Sharma, 2017, Fungi
and Plant Diseases, Kalyani Publishers, New Delhi-
110 002. Pg No : 262,263
• vikaspedia.in
• www.pestnet.org
• https://www.drysrhu.edu.in
• www.ccari.res.in
• www.agritech.tnau.ac.in