Diseases of Fruit Plantation Medicinal and Aromatic Crops

Cadang-Cadang

• The name Cadang-Cadang signifies 'dying-dying' from the dialect of Sioul area in Philippines and reflects the slow but persistent lethal progress of the disease. It is one of the most serious diseases of coconut in this country, which is also locally known as 'yellow mottle decline'.
  
• The slow reaction of the palm is a major problem to combat this disease. This disease is a slow killer, takes 5 to 8 years to die and thus only the older palms succumb. Young palms infected before yellowing stage, never bears fruits.
Soil: The disease incidence is influenced by poor nutritional status and poor soil structure. It is assumed that this disease is due to certain micro-nutrient deficiency, particularly copper or toxicity of nickel.

Symptoms

• The symptoms and its spreading nature have been generally accepted indicating its virus origin and the involved organism has been identified as viroid.
  
• The first visible symptom is the decrease in size of nuts, fibrous layer becoming thinner and thinner.
  
• Irregular yellow translucent spots appear in the pinnate of young leaves and turn orange-yellow mottling as the leaves mature and size and number of spots increase.
  
• On the lower surface of the leaves, a peculiar 'water-soaked' type of spot appears.
  
• Young leaves become short, brittle and frond as a whole become smaller and tend to remain in upright position in the crown.
  
• Both male and female flowers remain dwarf and the flower production usually ceases within second year after appearance of leaf symptoms.
  
• At a later stage, central fronds become bronze-yellow, main bud dies and falls showing crownless.
  
• As the disease progresses, roots generally deteriorate and rotting becomes extensive.
Management

• Clean culture, cutting and burning of infected palms are suggested.
• Replanting with resistant dwarf cultivars is recommended.
• Good soil management may suppress this malady.