What it does
Flooded fields lead to abnormal plant growth. It limits oxygen and sunlight, thus limiting the plants' food.
Why and where it occurs
Rice stems have nodes, which break when tremendous pressure due to strong wind/rainfall occur.
Cloudiness lessens the process of food-producing photosynthesis. Less food makes rice plant to weaken and lodge.
Flooding can occur anywhere that water can back up. Some pests also attack rice crops grown in flooded fields. For example, the yellow stem borer Scirpophaga incertulas (Walker) is considered a major insect pest. It causes deadhearts (death of stems) at rice vegetative stage, whiteheads (empty panicles) at reproductive stage, and decrease in filled grains/low panicle weight at maturity. The female moth is yellow with conspicuous wing spot. During the day the females rest prominently on the leaves, while males are nondescript in appearance. The eggs are laid in a flat mass covered with hairs from the female’s body. On the average, a female lays 2.7 egg masses, which total about 200 eggs. Egg hatching is completed in 1-3 days.
The Ufra nematode Ditylenchus angustus is also a pest of rice in flooded field. It causes mottling or chlorotic discoloration at the base of young leaves and crinkling of internal tissues followed by distortion or twisting and withering of young leaves.
At the field level there are differences in the reaction of cultivars.
How to identify
Plants damaged by flooding are usually elongated and week. Plants lose color turning gradually white, and leaves have a mud film.
How to manage
Learn more
View full fact sheet: Flooding on IRRI Rice Knowledge Bank