Plantation Crops

Diseases

Koleroga or Mahali or Fruit rot of areca
• Cause : Phytophthora arecae
• Season: Monsoon, High humidity alternating with bright sunshine and rain.

Symptoms
• Water soaked lesions on the surface of fruit. Later the lesions spread over to other lesions giving dark green colour.

• Neergole: ?Initial sysmptom
• Boosargole: ? Later stages

Control of Koleroga in arecanut
Spraying of Bordeaux Mixture ( 1 %) as prophylactic or preventive spray

I Spray = Onset of monsoon ( i.e., After first monsoon showers)
II spray = 40 to 45 days of first spray and there after if necessay
III spray = If necessary In place of Bordeaux mixture we can also use COC (Copper Oxychloride) /Blitox @ 3 g per liter of water can be used.
Collection and removal of affected plant parts and burning ? To reduce the inoculum
Note : Entire surface of nuts has to be covered fully which can be achieved by applying the solution as a very fine spray.
Tying of plastic bags/straw/Areca leaf sheath: The fruit bunches at different stages of maturity are tied with plastic bags/straw/Areca leaf sheath at the onset of monsoon after drenching with 1 per cent Bordeaux Mixture.