What is Citrus Tristeza Virus?
It is one of the most damaging diseases od citrus which is predominantly a bud union disease.
Susceptibility- All Citrus Species
Causal organism- Citrus Tristeza Virus (CTV)
Symptoms-
- Leaves – Yellowing, reduction in size and defoliation is the common symptoms of these disease.
- Stems & twigs – small branches and twigs with cracks on barks, pitting and twisting of stems occurs which later will die back.
- Fruits – The affected fruit are small size with increase in the thickness of rind.
- Roots – Root discoloration and rotting.
- As in the advances stages severe chlorosis and mottling occurs and eventually plant dries and wilt completely.
- The disease is also known as a quick decline disease due to reason that wilting symptoms on few trees shows overnight and completely dry up in 2 or 3 days.
| Stunting, yellowing of leaves, twig dieback and leaf defoliation | Death of sweet orange tree with fruits still hanging on the tree | Complete leaf defoliation and sudden death of sweet orange tree |
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Fig – Symptoms on fruits and leaves
Source – Kumar et. al., 2015
Source – Abubaker et. al., 2017 (First Report of Citrus tristeza virus (CTV) Disease in Commercial Citrus Orchards in Sudan)
Mode of spread-
- The disease may spread through the affected plant if not disposed properly
- Aphids (Toxoptera citricida) act as vector for spreading disease
Reason of severity-
- Lack of precautious measure for controlling vector
Management-
| Cultural Practices | Chemical Control |
| Maintain proper sanitation, proper tillage and good drainage system in the orchard. | The aphid should be controlled by spraying Dimethoate @ 1.5 ml per liter of water. Spraying Neem seed kernel extract @ 3ml per liter of water are also effective in controlling aphids.Foliar Spray – Abamectin 2% EC @ 1 gm per liter.Foliar Spray – Thiamethoxam 25 gm @ 1gm per liter |
Source –
Book – Field Problem of Fruit Crops, Dr. Amarjit Singh & Dr. Chander Mohan, PAU, Ludhiana
