Plantation Crops

Eriophyid Mite (Aceria guerreronis K.,)

2.Eriophyid Mite (Aceria guerreronis K.,)

• Eriophid mite has reached epidemic proportion in recent times affecting production and productivity in many districts of
  

  * Kerala,
  * TN and
  * Karnataka.

Method of damage
• Mites feed underneath bracts at the stalk end of nuts which are whitish and soft with fast multiplying cells. Entry of mites will take place when nuts are of 3-4 months stage since younger nuts will have tightly covered bracts in the perianth region without any space for the entry of mites in the soft region of nuts.
Nuts :
• Sap is sucked from tender meristematic tissues of immature nuts (buttons at 3 to 4 months stage) under perianth lobes resulting in brown lesions. It invariably affects all the nuts of a tree and almost all the trees in a plantation. The mite being small, is carried away by the wind which acts as the agent of dispersal. Because of this reason it has become a difficult task to contain this pest from spreading quickly in a region.
• Reduction in size and quality of affected nuts: There will be reduced yield of copra with in the nut.
• Hardening of husk: The fibrous region in these nuts also becomes hard, hence dehusking becomes difficult.

Symptoms
• Premature nut shedding, when the infestation is severe.
• Size of nut and husk looses quality due to development of warts and splits on them.
• Malformation of nuts

Management / Control of mites.
• Twin reasons causing difficulty in mite control : The control of this mite has become a major problem because of Wind dispersal : speedy dispersal by wind and Faster rate of Multiplication : also due to its fast multiplication rate
• Root feeding : Root feeding of monocrotophos (10 ml in 10 ml water). However, a waiting period of 45 days has to be given before harvest.
• Spraying : Use of wettable Sulphur (@ 5 g/litre of water) or neemazal @ 5 ml /litre of water, or Monocrotophos ( for spray) or Dicofol @ 6 ml per liter of water ( Dicofol 20 EC = Kelthane)
• Nutrient Management : 5 kg Neem cake per palm + Recommended N and P + 31/2 kg MOP ( instead of recommended 2 kg) + 1 kg Gypsum (Gypsum = CaSO4.2H2O) + 50 g Borax per palm per year.