RICE MORPHOLOGY IDENTIFICATION

Rice is native to tropical and subtropical regions of Southeast Asia and Africa.

Stem: Rice is an annual plant, the stem can be up to 1-1.8 m high, sometimes higher.

Leaves: Leaves are thin, narrow (2-2.5 cm) and 50-100 cm long.

Flowers: Small rice flowers of self-pollinating species grow in curved or drooping branched inflorescences, 30-50 cm long.

Seeds: Seeds are the type of fruit (small, hard seeds of cereal plants) 5-12 mm long and 2-3 mm thick.

Young rice plants are called seedlings. After soaking and incubation, people can sow germinated rice seeds directly into plowed and harrowed rice fields or through the seedling stage in separate fields so that the young rice plants can grow well, after a period of time, the seedlings are pulled out to transplant in the main rice field. The product obtained from the rice plant is rice grains. After removing the outer shell, the main product is rice and the by-products are bran and husk. Rice is the staple food of more than half of the world’s population (mainly in Asia and Latin America), making it the most consumed food by humans.

During the growth process, rice plants go through many different growth stages. At each stage, rice plants have clear identifying characteristics. This is an important basis for distinguishing and having reasonable solutions.

IMPORTANT GROWTH STAGES OF RICE PLANT

Based on farming practices and agronomic characteristics, rice plants are divided into 4 growth and development stages.

Seedling stage (also known as “Healthy seedlings”): is calculated from the time of sowing until 3.2 leaves appear (~20 days after sowing – NSS) (Lancashire et al, 1991). If it is transplanted rice, the seedling stage is the time the rice plant is in the seedling field or seedling tray.

Tillering stage (also known as “Sung bui”): is calculated from after the seedling has 3.2 leaves until the rice plant reaches the maximum number of shoots.

Heading stage (also known as “Deu bui”): is calculated from when the rice plant differentiates panicles until the rice flowers.

Ripening stage (also known as “Full grain”): is calculated from when the rice flowers bloom until ripe. In each growth stage, there will be reasonable technical solutions to maximize the yield potential of the rice plant.

Yield Components

Rice yield is formed and directly affected by 4 factors, called 4 rice yield components. Rice yield = Number of flowers/unit area x Number of grains/flower x Ratio of full grains x Grain weight

The yield components are closely related to each other and the more these 4 components increase, the higher the rice yield, until these 4 components reach the optimal balance, then the rice yield will be maximum. Exceeding this balance, if 1 of the 4 yield components increases further, it will adversely affect the remaining components, reducing yield.

The optimal balance between yield components to achieve high yield varies depending on rice varieties, soil conditions, weather and cultivation techniques.