Blast disease is a serious fungal disease affecting rice fields worldwide, with significant incidences in Japan, India, Taiwan, and the United States. The disease thrives in humid and wet areas and can cause significant crop losses of up to 90%. The blast illness is prevalent in India’s southern coastal districts. This disease has a devastating impact on rice production and threatens food security in several nations. Let’s check out more information on Rice Blast disease management in Paddy farming below.
Rice is a type of cereal grain. It is produced from the seeds of Oryza sativa (Asian rice) or Oryza glaberrima (white rice) (African rice). Rice is the most commonly consumed human staple food. It is the essential staple meal in Asia. Rice is the world’s third most-produced agricultural commodity. “Paddy” refers to unmilled rice.
Rice Blast disease management in Paddy
The causal organism of Rice Blast Disease
Blast is an infection caused by a fungus called Pyricularia oryzae, which is in the class of Deuteromycetes. There are different types of organisms, and each can infect a different type of rice plant differently. The pathogen makes two poisons called Pyricularin and Picolinic acid, which stop the plant from growing, which can live on collateral host plants like Panicum repens, Digitaria magrginata, and others.
Rice Blast Disease cycle
Blast often affects all above-ground portions of a rice plant, including the leaf, collar, node, neck, and parts of the panicle, as well as the leaf sheath. The neck and nodes are infected separately or jointly, causing identical symptoms. Blast disease can cause plants to produce few or no grains. The fungus spreads mostly through the mycelium and conidia found in straw, seeds, and other hosts. Conidia carried by the wind can spread to other fields through irrigation water. Pieces of the fungus can be found all year long.
Types of Rice Blast in Paddy crop
- Leaf blast: Leaf blast causes round, yellow-brown lesions with a black border on the plant’s leaves.
- Neck blast: A neck blast causes restricted development and lower grain production by affecting the stem close to the panicle.
- Stripe blast: causes the stems and leaves to develop long, thin, yellow-brown stripes.
- Sheath blast: Affects the sheaths of the leaves, turning them yellow until they finally take on the color of straw.
- Boot blast: Impact the growing panicles, turning them yellow and brown.
Causes/conditions favorable for Rice Blast disease spread in the field
- Intermittent drizzles
- Cloudy weather