He Sunflower life cycle Is started when the seed is planted in places of warm climate where many hours of sunshine are received per year. Germination can be delayed five to twelve days after being planted, provided that the conditions of temperature and soil moisture are optimal.
Once the seed germinates, it is in charge of rooting deep into the earth. To the outside of the seed leaves only a stem, that is in charge of surpassing the surface of the earth. A single sunflower can develop roots up to 1.8 meters deep that support heights of up to three meters.
Scheme of the cycle of life Sunflower: born, dies and re reproduces.
Sunflowers are very particular plants, since they always try to orient themselves facing the sun and throughout their lives they develop strong and deep roots that allow them to reach significant heights in comparison with other flowers. Once they reach maturity, they are essential for the process of pollination of bees.
The life cycle of the sunflower is divided into six stages ranging from seed sowing to growth, death and renewal of the cycle of each flower, being a relatively fast cycle.
Sunflowers usually grow in summer, when the weather is warm. They are called in this way because the flower will always try to orient itself towards the star as it moves (Sieverson, 2017).
Sunflower Life Cycle Processes
1- Seeding the seed
The life cycle of sunflowers starts when these are small seeds. Normally, these seeds are covered by a thick layer that can be black with stripes of cream color or completely black.
Sunflower seed is protected by this layer when the weather is hostile. However, once the conditions are favorable for the seed to germinate and the temperature increases, this layer will fall, allowing the roots of the sunflower to sprout.
Sowing of sunflower seeds occurs during spring, when the temperature is warm. This is because sunflowers need to receive a lot of sunlight throughout their lives in order to grow.
2- Germination of the seed
Planted sunflower seeds begin to germinate or sprout after five days, although some seeds may take a little longer, taking up to 12 days to sprout.
The protective layer of the seed softens during this process due to soil moisture and, thanks to the increase in temperature, this layer falls, allowing the roots of the seed to sprout.
The first root that springs from the seed is anchored deeply in the earth and a single stem is in charge of surpassing the level of the earth. Once the stem grows and surpasses the level of the earth, it receives the name of seedling (Yastremsky, 2014).
3- Growth of the seedling
The seedling continues to grow as the temperature increases. In this same way, the root of the sunflower also grows deep, anchoring to the earth. This root can reach up to 1.8 meters deep, allowing the sunflower to grow tall and heavy.
As the seedling develops, it sends a message to the root so that it grows too. In this way, the root acts as if it were the anchor of a ship that in turn has the capacity to obtain water and nutrients from the earth.
This root will always consist of a preponderant axis (pivoting root) and several smaller roots radially located along the main root (Jones & Brundle, 2015).
The stem of the seedling will continue to grow and will develop more blade-shaped leaves as it becomes taller. This stem initially is hollow, smooth and rounded and will give way to the growth of a flower bud after thirty days. Once the button begins to grow, the stem becomes strong, angular and thick.
While the bud of the flower is young, it will follow the sun from east to west as it moves on the horizon during sunny days. In this way, the sunflower button will point east in the morning and west in the afternoon. This phenomenon ceases to occur once the sunflower reaches maturity.
The stem height of a mature sunflower can range from about 2.4 to 3.6 meters. Some researchers at Purdue University have noted that the best conditions to ensure the growth of a sunflower occur when the temperature reaches 25 ° C (Burghardt, 2008).
4- Flowering
The sunflower bud takes about three weeks to become visible at the end of the plant stem. This button begins to grow until finally it opens, taking shape of disc with yellow petals.
In the course of the week following its blossoming, the yellow petals of the flower are rolled back over the edges of the button head.
After a week the sunflower drops its petals and the secondary shoots located at the bottom of the stem can flower like smaller buds (Thomson, 2010).
5. Wilt
After a season of growth and life, the petals of the sunflower begin to fall and the flower begins a wilting process. Eventually, the sunflower button will shrink and release seeds so that they fall into the deeper parts of the soil surface.
Once the sunflower finishes its flowering process, the points in the central part of the bud swell to seed, taking about thirty days to mature. Once they mature, each seed dries and gradually falls to the ground and is taken by small rodents, birds or humans to be consumed as food.
As the seeds mature, the rest of the sunflower plant begins to shrink, taking on a yellowish color. This phenomenon happens because all plant energy is focused on the growth of new seeds (Royston, 1998).
6- Rebrote
Once the sunflower seeds settle in a suitable place, the sunflower's life cycle begins again.
When all seeds mature and fall naturally, the sunflower plant stops growing and only dies at nightfall, when the temperature drops (Phelps, 2015).
References
- Burghardt, J. (2008). Garden Guides. Retrieved from The Life Cycle of a Sunflower Plant: gardenguides.com.
- Jones, G., & Brundle, H. (2015). Life Cycle of a Sunflower. Book Life.
- Phelps, B. (2015). The Life Cycle of a Sunflower. PowerKids Press.
- Royston, A. (1998). Life Cycle of a Sunflower. Heinemann Library.
- Sieverson, D. (2017). com. Retrieved from Sunflower Lesson for Kids: Facts & Life Cycle: study.com.
- Thomson, R. (2010). A Sunflower's Life Cycle. New York: The Rosen Publishing Group.
- Yastremsky, M. (2014, July 22). The Petal Talk. Retrieved from THE LIFE CYCLE OF A SUNFLOWER: 1800flowers.com.