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Download Publication ID: 3976
The pollination process in rice production is critical to overall productivity, as it directly impacts grain formation and yield. Optimal environmental conditions during pollination play a crucial role in the success of the crop, leading to potentially higher yields and better quality.
Rice plants have perfect flowers on the panicle, containing both pistils (stigmas, styles and ovaries) and stamens (two-celled anthers and filaments). Under normal conditions, self-pollination occurs when pollen grains fall from the anther onto the stigma. It takes about four to seven days for a full panicle to complete flowering.
Understanding the ideal pollination environment and the impacts of environmental stressors, such as high nighttime temperatures and excessive rainfall, is essential for optimizing yields.
For optimal rice pollination, certain environmental conditions must be met (Figure 1):
Figure 1. Ideal conditions allow for proper pollination.
Rice flowers, or florets, typically open for pollination during the early morning hours (Figures 2 and 3). The process usually begins around 9 a.m. and continues until noon, though this can vary slightly depending on the rice variety and environmental conditions. During this time, the anthers release pollen, which lands on the stigma, leading to fertilization.
Figure 2. Rice flowers, or florets, on rice panicle open for pollination.
Figure 3. Rice flowers begin at the tip, then move down the rice panicle.
High nighttime temperatures, especially those exceeding 75 F, can severely impact rice pollination. Elevated temperatures during the night can cause the following:
Figure 4. Anthers extended from the lemma and palea.
Figure 5. Two panicles that show multiple flowers during pollination.
Figure 6. Tips of the lemma and palea (hulls) are open and filaments are elongated.
Excessive rainfall during the heading and pollination stages can pose significant challenges including:
P3976_PollinationinRiceProduction_AG1224pdf / 2.23MB