Rice Diseases
Bakanae disease in Rice
Causal agent;- Gibberella fujikuroi
Host plant ;-
Maize (zea mays),Rice (Oryza sataiva),Sorghum (Sorghum spp),sugar cane (Saccharum officinarum).
Alternate hosts include Leucaena leucocephala, Lycopersicon esculentum (tomato), Musa sp. (banana) and Vigna unguiculata (cowpea). In Japan, the pathogen has been found on Panicum miliaceum.
Distribution;-
The pathogen is widespread in all rice-growing countries of the world. It has never been recorded on rice within the rice-growing area of South eastern Australia. In Queensland, the disease has been found on one occasion in a glasshouse but has never been found in rice fields.
Symptoms and Damage;-
Bakanae is a seedling disease, but it can be observed throughout the growing season. The earliest symptoms of bakanae are infected seedlings that appear to be elongated, thinner and slightly chlorotic when compared with healthy seedlings. .
The rapid elongation of infected seedlings can be up to 3 times taller than healthy seedlings. The rapid elongation of infected plants is due to the production of gibberellin, a plant hormone, by the fungus. Symptom development is influenced by the amount of inoculum present, the strain of the pathogen and the relative quantities of gibberellin and fusaric acid (which causes stunting) produced. Bakanae plants are often visible above healthy rice plants. If infected seedlings often progressively die from the seedling stage through to maturity. Infected plants survive to heading, the panicles they produce are usually sterile.
The flag leaf on mature plants is noticeable by its elevated, more horizontal stance. The fungus sporulates profusely on the stems of diseased plants near the water level, and after the water is drained, noticeable pink to white fungal growth appears at the base of the plants. This cottony growth produces masses of conidia which contaminate the outside of healthy seeds during harvest.
Disease cycle;-
Bakanae is primarily a seed
Causal agent;- Gibberella fujikuroi
Host plant ;-
Maize (zea mays),Rice (Oryza sataiva),Sorghum (Sorghum spp),sugar cane (Saccharum officinarum).
Alternate hosts include Leucaena leucocephala, Lycopersicon esculentum (tomato), Musa sp. (banana) and Vigna unguiculata (cowpea). In Japan, the pathogen has been found on Panicum miliaceum.
Distribution;-
The pathogen is widespread in all rice-growing countries of the world. It has never been recorded on rice within the rice-growing area of South eastern Australia. In Queensland, the disease has been found on one occasion in a glasshouse but has never been found in rice fields.
Symptoms and Damage;-
Bakanae is a seedling disease, but it can be observed throughout the growing season. The earliest symptoms of bakanae are infected seedlings that appear to be elongated, thinner and slightly chlorotic when compared with healthy seedlings. .
The rapid elongation of infected seedlings can be up to 3 times taller than healthy seedlings. The rapid elongation of infected plants is due to the production of gibberellin, a plant hormone, by the fungus. Symptom development is influenced by the amount of inoculum present, the strain of the pathogen and the relative quantities of gibberellin and fusaric acid (which causes stunting) produced. Bakanae plants are often visible above healthy rice plants. If infected seedlings often progressively die from the seedling stage through to maturity. Infected plants survive to heading, the panicles they produce are usually sterile.
The flag leaf on mature plants is noticeable by its elevated, more horizontal stance. The fungus sporulates profusely on the stems of diseased plants near the water level, and after the water is drained, noticeable pink to white fungal growth appears at the base of the plants. This cottony growth produces masses of conidia which contaminate the outside of healthy seeds during harvest.
Disease cycle;-
Bakanae is primarily a seed