Causal organism:- ustilago noidea virus

Symptom

1. False smut start as light green ball of spores covered by a thin silver colored skin. The balls erupt exposing the orange spores.

2. As time passes spores turn dark green to black. Damage from smuts occur due to contamination of other grains by spores during harvest, miiling causing quality problems and discoloration during paraboiling and cooking.

Management

1. Excessive nitrogen increases diseases.

2. Use resistant varities

- Use of recommended doses of fertilizer.

- Deep ploughing in summer stubbles.

- Avoid flow of irrigation water from infected fields to healthy fields.

- Chemical spray: 2 spray of 0.1% Propiconazole (Tilt) solution (1 gm/lt water).

First spray before panicle emergence and second spray 10 days just after panicle emergence.

Symptoms: The fungus transforms individual grains into greenish spore balls of velvetty appearance.

Due to the development of the fructification of the pathogen, the ovaries are transformed into large velvetty green masses. Usually only a few spikelets in a panicle are affected.

1. Causal organism: Sarocladium oryzae (Sawada) W. Gams & D. Hawksw.

2. The pathogen generally attacks the upper most leaf sheath enclosing the young panicles.

3. Oblong or irregular spots with chocolate brown colour develop on the boot leaf sheath. Sheath rots disease of rice, caused by Sarocladium oryzae.

4. It inflicts damage to the uppermost flagleaf sheath by infecting the sheath covering the young panicles at the booting stage.

1. In one panicle, only few seeds showing the disease symptoms.

2. Individual grains of the panicle are transformed into yellow or greenish velvety spore balls.

3. The spore balls are covered by a membrane in the early stages, which bursts on further growth and the loose velvety pseudomorphs become visible.

1. Low temperature (20°C).
2. High relative humidity (>92%).
3. Moderate rainfall with intermittent clear and drizzling weather during flowering.
4. More prevalent in seasons favorable for good growth and high yields.
5. Host pants: Grasses and Wild rice.

Causal organism: Ustilaginoidea virens (Cke.)

Local name:

False smut is a fungal disease and is more severe in the years of high rainfall.

The farmers consider its incidence as an omen of Good Harvest.

Period of occurrence : Panicle emergence .

Extent of yield loss : Negligible, Udupi district 23% and DWR 3%.

• 1000 grain weight by 48%.

• Chaffyness by 40%.

• Seedling growth.

1. Symptoms become evident on infected grains after flowering: a grain turns into a large velvety mass (pseudomorph). The pseudomorphs are small to more than 1 cm in diameter, and enclose the floral parts. The colour changes from silvery-white to orange-yellow to olive-green when mature.

Common names of False Smut disease: False smut, green smut.

Preferred scientific name of False Smut: Ustilaginoidea virens (Cke.) Tak. (1896) [anamorph].

Distribution and Occurrence of False Smut: Found in coastal areas of Karnataka and sporadic (Singh, 1984 and POS report, 2009).

False Smut

Symptoms of False Smut

1. Symptoms of the false smut will be seen only after flowering.

2. The pathogen, Ustilaginoidea virens, grows in the ovary and transforms it into large, yellowish and velvety green balls, which become greatly enlarged at later stage.

3. The spore balls are covered by a membrane in the early stages, which bursts on further growth and the loose velvety pseudomorphs become visible.