Disease of Arecanut

   Koleroga

Koleroga is a major disease of arecanut causing serious losses.  The pathogen is a fungus Phytophthora palmivora. Spraying the bunches with 1% Bordeaux mixture before monsoon followed by another spray after 45 days is effective in preventing the disease.  Covering the bunches with polythene bags is an effective alternate method of control.

Yellow Leaf Disease

Yellow Leaf Disease of arecanut is characterised by typical yellowing of the lower whorl of leaves.  There is a gradual decline in yield.  The pathogen is identified as Phytoplasma.  It is spread through plant hoppers .  Practices for managing the disease are being evolved.

Anabe

Anabe disease is caused by a fungus Ganoderma.  It is controlled by root feeding with Calyxin  followed by Phytosanitation and isolation.                                   

Yellow Leaf Spot

Seedlings exposed to the sun are susceptible to this disease. The disease is severe during summer months and continue to infect seedlings until the onset of rains. Small brown spots on the  lamina,  which  later coalesce  to form large blighted areas. Severely affected palms exhibit shedding, drying and drooping of leaves.

Nut splitting

This is considered to be a physiological disorder rather than a pathological disease. The disease characterised by the cracking fruits known as 'Anduadakke roga' in Kannada. The disease is known as 'Achikeeral' in Kerala. This abnormality is seen in patches in individual gardens and are common in young palms. 
Premature yellowing of nuts followed by the cracking of fruits are other symptoms observed. Cracks develop near the  perianth  end  or at the  base or at both sides. Kernel also at times exhibit splitting.                                                                           

Inflorescence die-back and Button shedding

Die-back of inflorescence due to the association of micro-organisms    is reported to be associated with the low fruit set in arecanut. About 60% of the palms in the states of Karnataka and Kerala are infected by this disease causing severe shedding of buttons. No systematic survey has been conducted to assess the crop loss caused by this disease. Yellowing and drying of the rachis from the tip towards the base followed by shedding of female flowers (buttons).

(Source :Central Plantation Crops Research Institute,

 Kasaragod 671 124, Kerala, India)