DISEASES OFMANGO AND ITS TYPES

Описание: DISEASES OF MANGO AND ITS DISEASE TYPES...
Session-9
DISEASES OF MANGO
9.1 ANTHRACNOSE
Causal organism: Colletotrichum gloeosporioides
Sub-division: Deuteromycotina
Symptoms
On leaves initially circular, light yellow brown spots are produced which soon enlarge with
dark brown to black margins. If infection is severe individual spots coalesce leading to
twisting of foliage and premature defoliation. On fruits Spots appear near the stem end as
small brown areas that enlarge rapidly and become black. Fruit pulp beneath the spots
become hard followed by cracking and decay at ripening.
Fig 9.1: Anthracnose of Mango
Disease cycle
Primary infection: Mainly through previous season infected leaves, defoliated branches,
mummified flowers and flower brackets.
Secondary infection: Mainly due to rain splash or wind driven rain water.
Favourable conditions:
Temperature of 25°C and R.H 95-97% along with Moist and humid condition favourable for
the disease.
Management
 Avoid over-crowding of orchards. Tree sanitation is important. Diseased twigs are
to be pruned and burnt (along with fallen leaves.)
 Spray carbendazim (0.1%) or Chlorothalonil (0.2% at 14 days intervals until
harvest.
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 Before storage, treat the fruits with hot water (50-55°C), for 15 minutes or dip in
Carbendazim solution 0.1%.
9.2 MANGO MALFORMATION
Causal organism: Fusarium moniliformae sub sp. subglutinans
Sub-division: Deuteromycotina
Symptoms
Vegetative malformation:
The affected plants develop excessive vegetative branches which are of limited growth,
swollen and have short internodes.Sometimes the branches show a bunchy top appearance,
compact leaves are formed in a bunch at the apex of shoot or in the leaf axil.
Floral malformation:
The flowering panicles instead of coming out as a normal one into just compact bunch of
hard flowers. Individual flower is greatly enlarged and has a large disc. The inflorescence
gets hypertrophied. The percentage of bisexual flowers in malformed panicles is very low.
The malformed heads dry up in black masses and persist on the trees for a long time.
Fig 9.2: Mango Malformation
Disease cycle
Primary infection: Through malformed inflorescence.
Secondary infection: Either by air borne conidia or by conidia carried by eriophid mite
Aceria mangiferae.
Favourable conditions:
Younger plants are more susceptible, vegetative malformation reduces with growing age.
Mild temp. (8-27 0C) and high RH more than 85% are conducive.
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Management
 It is advisable to avoid scion-stick from trees bearing malformed inflorescence for
proportion.
 Only certified saplings should be used for propagation.
 Healthy orchards located in disease prone pockets should be sprayed with
fungicides like carbendazim (0.1%).
 Spray 200ppm NAA before blossoming.