As the rice plant grows, the panicle will make its way up the inside of the culm, or stem. The flag leaf (final leaf) will appear and stick out sideways, indicating the rice is entering the booting stage of the reproductive phase.
The panicle will be visible in the boot, and a leaf sheath will protect the panicle until it starts to exsert, or push out, from the boot.
Heading is when the rice panicle starts to grow outside the boot. “Heading throughout an individual field takes about 10 to 14 days due to variations with tillers on the same plant and between plants in the field.”
Rice heading is said to be complete when 100 percent of the panicles have completely emerged from the boot.
After the panicles have completely emerged, it is time for pollination. The protective rice hull opens to reveal reproductive parts of each panicle. Flowering, or anthesis, is when the tiny flower, also known as a spikelet, opens for a couple of hours for pollination to occur. Panicles usually open to reveal the reproductive parts of the plant between 9 a.m. and 3 p.m.
According to the Arkansas Rice Production Handbook, “pollen grains are viable for about five minutes after emerging from the anther, whereas the stigma may be fertilized for three to seven days.”
The flowering process of the entire panicle takes about four to seven days. Then, the grain ripening or maturation phase begins.
Karen Moldenhauer, Charles E. Wilson, Jr., Paul Counce and Jarrod Hardke, “Rice Growth and Development,” Arkansas Rice Production Handbook (2012): 17.
 Ibid, 17.
 Ibid, 18.