Disease : Root (Wilt)

Root wilt ,which was seen mostly in the southern districts of Kerala is now observed throughout the State in varying intensities. However, the incidence is more in Alappuzha, Kottayam, Eranakulam and Pathanamthitta districts.

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  • The predominant symptoms of the disease are flaccidity, abnormal bending of the leaflets or ribbing of leaflets.
  • Flaccidity is due to impaired stomatal regulation resulting in excessive transpiration.
  • The leaflets curve inwardly to produce ribbing so that the whole frond develop a cup like appearance.
  • Foliar yellowing and marginal necrosis are other symptoms associated with this disease.
  • Diseased palms show extensive rotting of roots.
  • Main roots and rootlets start drying from tip in bearing palms.
  • Shedding of immature buttons is also noticed.
  • Drying of spathe and necrosis of spiklets is noticed in certain cases.
  • Severely affected palms produce fewer female flowers.
  • The nuts from the diseased palms have thinner kernel and husk.
  • The fibres are weaker and less firm.
  • The oil content may be reduced considerably.
  • The root wilt affected palms are susceptible to disease such as leaf rot and pests such as rhinoceros and red palm weevil.
  • The intensity of root wilt damage is usually aggravated by the infection by leaf rot pathogen.

Procedure for Observation

Look for the incidence of the disease in the garden.


Mere presence


Plant hopper Proutista moesta and lacewing bug Stephanitis typicus transmit Phytoplasma . Abiotic factors such as disturbance in uptake and translocation of nutrients, higher rate of transpiration and respiration, changes in nitrogen and phenol metabolism aggravate the disease.

Control Measures

  • Apply balanced doses of fertilizer at the rate of 0.34 kg N, 0.17 kg P and 0.68 kg K/ palm /year in the form of urea, rock phosphate and muriate of potash respectively (average management).
  • For good management apply N, P and K at the rate of 0.5 kg N, 0.32 kg P, and 1.2kg K/palm/year.
  • Under rain fed conditions, apply 1/3rd fertilizers during April-May and 2/3rd during September-October.
  • Apply 50 kg cattle manure or green manure and 1 kg of lime/palm/year.
  • Apply MgO @ 500g/palm/year in the Onattukara region and 100g MgO in the remaining areas.
  • Under irrigated conditions apply fertilizers in three equal splits (April-May, August-September and December-January).
  • Grow green manure crops like Sesbania, Cowpea, Calapagonium and Pueraria phaseoloides in the coconut basin and incorporate them in situ.
  • Apply Trichoderma and Pseudomonas fluorescence at the base to enhance soil health immediately after incorporating green manure.
  • Sequential spraying of Bordeaux mixture 1%, Mancozeb (0.3%) and Copper oxychloride (0.3%) so as to manage other fungal diseases associated with root wilt.
  • Irrigate palms during summer months.
  • Provide proper drainage.
  • Raise intercrops in rotation, adopting mixed cropping/mixed farming with recycling of organic matter.
  • Desilt the channel and strengthen the bunds during summer months when the crop is grown under the bund and channel system.
  • Remove all severely diseased and uneconomic palms, which produce less than ten nuts per year and replanting with hybrids CGD X WCT or Chandrasankara (COD X WCT).
  • Control the vectors of the pathogen by spraying 2 % neem oil garlic emulsion, covering both the surfaces of the leaves based on need.