Citrus Gummosis

< Back to Package of Practice

What is Citrus Gummosis?

Gummosis is one of the main diseases which is represented by gum oozing from the cracks. Infection may occur from soil due to extended periods of moist and wet conditions. It is more common in heavy soil, ill drained and high-water table soils.

Susceptibility – Lemons & sweet oranges are highly susceptible, rough lemon & grapefruit are less susceptible whereas mandarins and sour orange are tolerant.

Causal organism– Phytophthora palmivora, P. citrophthora, P. nicotianae var. parasitica

Symptoms-

  • The characteristic symptoms are the brown gum oozing from the vertical crack of infected bark giving bleeding appearance.
  • The crack on bark would eventually open wider, dries and shed off which will lead to secondary infection by micro-organism.
  • The bark stays firm, dries and eventually cracks and breaks away from healthy bark.
  • Later, the damage on the bark results in the girdling of the bark and the trees eventually collapse and dies.
  • In such cases it is also known as collar rot or foot rot.
Fig- Symptoms of Gummosis on tree trunk.Source- https://ucanr.edu/blogs/Topics/blogfiles/62331.jpg

Mode of Spread –

  • Flood Irrigation
  • Repeated use of same land

Reason of severity-

  • Due to stagnation of water in the orchard for longer period improper drainage facility
  • Due to injuries on cut portion
  • The disease is more severe during the moist and cool condition.

Management-

Cultural PracticesChemical Control
Deep ploughing followed by soil solarization should be followed before plantation.Proper sanitation of orchard to be followed.Proper drainage facility should be followed.Avoid flood irrigation & root injuries.Keep grafting union 6 – 8 inch above soil surface. Paint the tree trunk with Bordeaux paste (1:1:10) at 2- 2.5 ft from the ground level.Drench the soil with Tebuconazole 25.9% EC @ 0.6ml per liter water. 

Source:

Book – High Density Cultivation of Nagpur Mandarin – ICAR-CCRI, IARI

Book – Darjeeling Orange: Its Cultivation and Management, Dr. Jaishree Pradhan & Dr. Jiwan Prakash Pradhan