Scientific Name Zingiber officinale Rosc.
Local Name Adhuwa
Family Zingiberaceae
State/World wide Sikkim, Darjeeling, Arunachal Pradesh, Asia and South East Asia
Common Name of Disease: 2. BACTERIAL WILT
Local Name of Disease -Ohelini bimar or’Prem rog
Causal Organism -Ralstonia solanacearum
Distribution of Disease in Sikkim

-Disease incidence in maximum in high rainfall areas of North, East, and some areas of West Sikkim and less in South Sikkim.

Disease Incidence -Moderate to high
Site of Infection

- The bacteria find their way to the roots of ginger by swimming in soil water. They enter the roots through the wound caused by nematode or mau extraction. Once inside the roots, they enter the water conducting tissues and via these they travel to the rhizome and the stem.

Dissemination of the Disease - It is a seed-borne and soil borne disease.


Symptom is noticed during July-August in Sikkim. In severe cases result in total loss of crop.The disease is characterized by drooping and wilting of leaves even in early morning. The base of the pseudostem turns grey to dark and soft. The cut ends of the pseudostem or rhizomes when pressed exude a milky substance. The leaf margin of the affected plants exhibits yellow bronze coloured symptom and they curl backward. Ooze test positive confirms that it is bacterial wilt.

Favourable environmental condition for disease
Water stagnation in the field during rainy season.Hot and humid weather condition favours the disease incidence. Injury caused to the rhizome during mau extraction makes the plant susceptible to the disease.

Mode of Transmission
Disease is transmitted to a healthy plot through infected planting material, mechanical transmission through human activities. Drainage / run off water flowing across the diseased plot carrying fungal spores to a non-contaminated plot at the lower elevation.

Life cycle of Organism
Plant Protection Measures: Seed should be selected from a diseased free source. Fresh land free from disease inoculums should be selected based on previous history. Crop rotation of 4-5 years should be followed to avoid disease incidence.
Crop rotation should not be done with solanacous crop like tomato, potato, chilly, brinjal etc. Rather growing Cruciferous crop like mustard, radish would suppress the pathogen.Planting should be done on raised bed with proper drainage. Thick mulching should be provided to check weed growth and to conserve moisture. FYM should be well decomposed to avoid white grub infestation. Planting of ginger should be done on sloppy land to avoid water stagnation. Seed treatment with Trichoderma spp.+Pseudomonas florescens before sowing can control disease.

Brief history of the disease
Pseudomonas solanacearum (Smith) (which is now renamed as Ralstonia solanacearum) Smith 1914 is a soil borne pathogen which typically invade a host via root injuries or at the point of emergence of the root hairs and lateral roots. Some evidence has been presented of the organism’s ability to enter leaves of certain host via stomata. Bryan (1915) infected nasturtium leaves with a suspension of R. solanacearum and recently we showed that naturally occurring leaf spots of capsicum was caused by R. solanacearum (Hayward & Moffett 1978).In India, rotation with finger millet or maize was effective in reducing wilt of eggplant and tomato (Shoe et al 1981).In china, 3 years of rice cultivation reduced bacterial wilt incidence of ground nut from 83% to1.5% (Wang et al 1983).

Bioinformatics Sub- DISC, SSCS&T