Major diseases of Ginger are:-
1.Ginger Soft rot or rhizome rot: Pythium aphanidermatum/ P. vexans / P. myriotylum
- The infection starts at the collar region of the pseudostems and progresses upwards as well as downwards. The collar region of the affected pseudostem becomes water soaked and the rotting spreads to the rhizome resulting in soft rot.
- At a later stage, root infection is also noticed.
- Foliar symptoms appear as light yellowing of the tips of lower leaves which gradually spread to the leaf blades
- In early stages of the disease, the middle portion of the leaves remains green while the margins become yellow.
- The yellowing spreads to all leaves of the plant from the lower region upwards and is followed by drooping, withering and drying of pseudostem.
- Treatment of seed rhizomes with mancozeb 0.3% for 30 minutes before storage and once again before planting reduces the incidence of the disease.
- Cultural practices such as selection of well-drained soils for planting is important for managing the disease since stagnation of water predisposes the plant to infection.
- Seed rhizomes are to be selected from disease free gardens since the disease is also seed borne.
- Once the disease is located in the field, removal of affected clumps and drenching the affected and surrounding beds with mancozeb 0.3% checks the spread of the disease.
2.Ginger Bacterial Wilt: Ralstonia solanacearum
- Water soaked spots appear at the collar region of the pseudostem and progress upwards and downwards.
- The first conspicuous symptom is mild drooping and curling of leaf margins of the lower leaves which spreads upwards
- Yellowing starts from the lowermost leaves and gradually progresses to the upper leaves. In the advanced stage, the plants exhibit severe yellowing and wilting symptoms.
- The vascular tissues of the affected pseudostems show dark streaks. The affected pseudostem and rhizome, when pressed gently, extrudes milky ooze from the vascular strands.
- The cultural practices adopted for managing soft rot are also to be adopted for bacterial wilt.
- The seed rhizomes may be treated with streptocycline 200ppm for 30 minutes and shade dried before planting.
- Once the disease is noticed in the field all beds should be drenched with Bordeaux mixture 1% or copper oxychloride 0.2%.
3.Ginger Leaf spot: Phyllosticta zingiberi
- The disease starts as water soaked spot and later turns as a white spot surrounded by dark brown margins and yellow halo. The lesions enlarge and adjacent lesions coalesce to form necrotic areas.
- The disease spreads through rain splashes during intermittent showers.
- The incidence of the disease is severe in ginger grown under exposed conditions.
- The disease can be controlled by spraying Copper oxychloride 0.25 % or Mancozeb 0.2%.
- TamilNadu Agritech Portal