Soft rot of Ginger, a serious problem in Ginger crop
Ginger Zingiber officinale Rosc. (Family: Zingiberaceae) is an herbaceous perennial, the rhizomes of which are used as a spice. India is a leading producer of ginger in the world and during 2012-13 the country produced 7.45 lakh tonnes of the spice from an area of 1. 56 hectares.
Ginger is cultivated in most of the states in India. However, states namely Karnataka, Orissa, Assam, Meghalaya, Arunachal Pradesh and Gujarat together contribute 65 per cent to the country’s total production.
Major problems of Ginger crop growing.
1. Soft Rot diseases caused for Pythium aphanidermatum. Pythium vexans and Pythium myriotylum -- Fungi
2. Bacterial Wilt caused by Ralstonia solanacearum
3. Leaf spot diseases are caused by Phyllosticta zingiberi, Helminthosporium, Colletotrichum, Pyricularia
4. Root knot Nematodes (Meloidogyne spp., Radopholus smilis, Pratylenchus spp.) also infests ginger crop in some areas and some seasons.
5. Shoot borers (Conogethis punctiferalis) cause holes in the pseudostems leading to major crop losses
6. White grubs (Holotrichia spp.) are also major pests of ginger crop.
7. Rhizome Scale (Aspidiella hartii) sometimes attack ginger crop cause major losses.
Among them soft rot disease is more severe in high moist areas with little lower temperatures
Soft Rot disease is caused fungi Pythium aphanidermatum, Pythium vexans and Pythium myriotylum.
Symptoms of soft rot caused by Pythium spp.
Nature of Damage:
- The fungi builds up along with the soil moisture especially during the monsoons.
- Young sprouts are the more susceptible ones.
- The collar region of the pseudostem affected by soft rot becomes water-soaked.
- The rotting spreads reaching the rhizome.
- The rhizomes grow soft and begin rotting and hence the name ‘soft rot’
Leaf symptoms of soft rot caused by Pythium spp.
Symptoms of the disease
- Affected region becomes water soaked
- Middle portion of leaves are green while margins turn yellow.
- Yellowing spreads upward as well as downward to other regions.
- Pseudostems dry and wither
- The infected shoots are very easy to pull out from the soil.
Rhizome rot caused by Pythium spp.
Spreading of Disease
- Spreads through rhizomes
- Affected spores present in soil
Management of Disease
- The most important step here is to select soil that does not hold water soil must drain off water quickly.
- Seed rhizomes must be chosen from disease-free gardens.
- Drench with Ridomet75 gm per litre and drench in dry conditions and 2-3 gm per litre in wet or rainy conditions.
- After 6 days Neel Cu [Copper EDTA]5 gm per litre and drench in dry conditions and 1.5 - 2 gm per litre in wet or rainy conditions.
- Seed treatment with Ridomet 1 gm/L of water and spray on the seed rhizomes stored in dry conditions spray should done uniformly on the cut seed rhizomes. This seed treatment may help prevent the disease at later stages.
K SANJEEVA REDDY,
Senior Agronomist, BigHaat.
For more information kindly call on 8050797979 or give missed call on 180030002434 during office hours 10 AM to 5 PM
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