Anthracnose


Anthracnose
Anthracnose :
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C.O.: Colletotrichum gloeosporioides
Per.stage: Glomerella cingulata

Symptoms:

• Brown or dark circular or irregular spots formed on tender leaves
• Infected leaves shows “shot hole” appearance
• Tip of young branches gets dried from top to down
• Blossom blight is most destructive phase
• Blackish brown specks appear on peduncles and flowers which enlarge and causes death of flowers.
• Black spots formed on fruits slightly sunken.Spots coalesces and forms irregular big patches followed later by cracking and decay at ripening.

Predisposing factors:

• Humid and moist conditions are favourable for infection.
• Optimum temp for infection 250 C & RH. 95-97%.

Management:

• Collect disease leaves, twigs and fruits and destroy them.
• Prune infected twigs, branches and burn it.
• Pruning of diseased twigs should be followed by three sprays carbendazim 0.03% or copper oxychloride or Zineb @0.2%.
• Post harvest control: Hot water treatment at 51◦C for 15 min.
• Fruit dip at 55◦Cor 5min. in solution of benomyl (0.0125%) 2.5g/10liter water or thiabendazole 1000 ppm for 5 min


Malformation

Malformation
Malformation :
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C.O.: Fusarium moniliforme var. subglutinans Wollenw. & Reink.

Symptoms:

• Bunchy top phase (BT)
• Vegetative malformation (VM)
• Floral malformation (FM)

Management:

• Avoid using scion/stocks from infected plant.
• Select healthy diseases free plants for planting.
• Pruning of affected terminals 15-20 cm along with healthy portion & burn it.
• Spray 200 ppm NAA in first week of October followed by de-blossoming at bud burst stage.
• De-blossom early flowers.
• Foliar spray with carbendazim 0.05 % or benlate 0.20%
• Spraying of acericides for control of vector (mite).


Powdery mildew
Powdery mildew of mango :
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C.O.: Oidium mangiferae

The disease is reported to cause approximately 20 to 80 % fruits loss.

Symptoms:

• The characteristic symptom of the disease is the white superficial powdery fungal growth on leaves, stalks of panicles, flowers and young fruits.
• Premature flower and fruit drop.

Predisposing factors:

• Warm humid weather and cool nights favour the spread of the pathogen within and between trees.
• Cloudy weather with rains or heavy mist in morning and cool nights during flowering.
High wind velocity for 3-4 days, maximum temperature 30o C. minimum temperature 15o C and R.H. 73-84 % and minimum R.H 23 to 26 %.
• Unseasonal rains or mists accompanied by cooler nights during flowering are congenial for the disease spread.

Management :

• Three sprays with hexaconazole 0.005% or carbendazim 0.025% or weattable sulphur 0.2 % or dinocap 0.05 %,at fifteen day interval.