CPCRI Advisory: Combating Fruit Rot in Arecanut Plantations

Understanding Fruit Rot Disease (Koleroga)

• Fruit rot disease, also known as koleroga, is a significant threat to arecanut plantations.
• Caused by fungi, bacteria,  or viruses, m  aking prevention and treatment challenging.
• Can lead to major crop losses, un  marketable produce, and sometimes plant death.

Favorable conditions for spread:

• • Heavy rainfall
  • Low temperatures (20 to 23°C)
  • High relative humidity (>90%)
  • Alternating sunshine and rain

Common symptoms include:

• • Brown or black spots on fruit
  • Softening and shrivelling of fruit
  • Mold growth
• Botrytis cinerea is a common fungus causing fruit rot in various crops.
• The disease can spread rapidly through wounds in leaves or fruit lesions.
• Some fungi produce toxins harmful to humans and animals.

CPCRI Advisory and Control Measures

• The Central Plantation Crops Research Institute (CPCRI) in Kasaragod issued an advisory for farmers.
• Immediate action recommended due to high prevalence in areas with incessant rains.

Key control measures:

a) Spray 1% Bordeaux mixture or Mandipropamid 23.4% SC (1ml per liter) on all bunches.

b) Apply spray even if fruit rot is not yet visible in the plantation.

c) For severe cases, spray both crown and bud regions to prevent bud and crown rot.

d) Do not mix other fungicides, pesticides, or nutrients with the spray.

e) Prepare Bordeaux mixture fresh with neutral pH (7).

f) Add a sticker-cum-spreader (1ml per liter) to the spray preparation.

g) Ensure proper mist spray of the fungicide.

Additional management practices:

a) Create proper drainage in the garden to avoid water stagnation.

b) Remove fallen diseased nuts from the garden.

c) Apply dolomite/lime (1kg per palm or based on soil test) in September.

d) After 2-3 weeks, apply recommended fertilizers:

• • 150g urea
  • 130g rock phosphate
  • 160g muriate of potash
  • 12kg FYM per tree

Importance of Timely Action

• Incessant rains have made koleroga quite rampant in some areas this year.
• Farmers who couldn't spray in July are experiencing high prevalence of the disease.
• CPCRI emphasizes the importance of taking control measures during breaks in rainfall.
• Prompt action can prevent further spread and minimize crop losses.
• Regular monitoring of plantations is crucial for early detection and treatment.
• Implementing the advisory can help protect arecanut crops and maintain their marketability.
• Proper management practices not only control the current outbreak but also help prevent future occurrences.