WILT DISEASE OF SUGARCANE
Causal Organism: Fusarium sacchari
Old: Cephalosporium sacchari
Vivek Kumar & Juhee Kumari
Student B.Sc.(H) Agriculture
School of Agriculture, GEHU (Dehradun)
INTRODUCTION:
The wilt disease of sugarcane was first reported from Bihar in 1906, and now it is a common and destructive disease occurring in many parts of our country such as U.P., Bihar, Haryana, Punjab, Gujarat, Andhra Pradesh, and Tamil Nadu.
It was first reported by Butler and Khan in 1913, from North India.
This disease caused great damage to sugarcane crop in the Deccan Plateau and to a lesser extent in other areas during 1965-67 and, because of it the sugar industry in the country was paralysed. This disease, however, often occurs in association with the red rot disease of sugarcane and is only second to red rot in causing economic loss to the crop.
Wilt of sugarcane appeared in epidemic form in many districts in Tamil Nadu during 1955-56 and, as a result, certain sugarcane varieties like Co419, Co449, Co453, Col 122 were withdrawn from cultivation. However, the disease is also known to occur in Bangladesh, Pakistan, Argentina, Philippines, South Africa, USA, Barbados, Trinidad, Columbia, Zimbabwe, and Mexico.
CLASSIFICATION:
Kingdom : Fungi
Division : Eumycota
Sub-division : Deuteromycotina
Class: Hypomycetes
Order: Moniliales
Family: Moniliacease
Genus : Fusarium
Species : sacchari
SYMPTOMS:
- The first symptoms of the disease become apparent only when the plant has grown for about 4-5 months.
- Then gradual yellowing and drying of foliage, shrinkage/withering of canes.
- If the affected canes are cut and examined, the pith will be Light to dark purplish or brown discolouration of ground tissue, pithiness and boat shaped cavities in the middle of the internodes.
- A characteristic disagreeable odour is also associated with this disease.
- Often a cottony white mycelium is seen in the pith region.
- The fungal mycelium is hyaline, septate and thin walled.
- The conidiophores are simple or branched and produce single celled, hyaline, oval to elliptical microconidia.
- Macroconidia are straight with 3-5 septa measuring 27-73 × 3.4-5.2 mm.
- Blastoconidia are either straight, sickle shaper or pike shaped with 2-3 septae. Moreover will be found as elliptical cell shaper structure with 1.-43x3.0-4.5 mm in size.
- High day temperature (30-35˚C).
- Low humidity (50-60%).
- Low soil moisture and alkaline soils.
- Excess doses of nitrogenous fertilizers.
- The fungus is soil-borne and remains in the soil as saprophyte for 2-3 years.
- The disease is primarily transmitted through infected seed pieces.
- The secondary spread is aided by wind, rain and irrigation water.
- Selection of healthy seed setts from disease-free area for planting
- Grow resistant varieties like Co 617 and B.P.17 are more resistant than other varieties
- Crop rotation, managing root borer, avoiding prolonged drought and water logging and hygienic practices.
- Many species of Streptomyces and Bacillus are known to be the natural antagonists of the wilt pathogen. However their commercial has not been worked out.
- Dipping the setts in 40 ppm of boron or manganese, or spraying the plants with either of these minor elements reduces the disease intensity.
- Sett treatment with fungicide like Bavistin, 0.1 per cent before planting.
- Apply carbendazim @ 2gm/lit of water at the root zone area and same as follow at 15 days interval.
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