Introduction
Corn develops in several complex stages, which can vary based on the needed maturity period. The development stages are divided into five phases. The first stage is germination, the second one is vegetative growth, and flowering is the third. Fruiting and death are the fourth and fifth stages respectively. The five broad stages of corn development will be discussed in this paper.
Stages of Development
Stage 1: Germination
Immediately after a corn seed is planted, different metabolic reactions start to take place. With the right conditions, which include soil temperatures between 50 and 65 degrees Fahrenheit and adequate moisture, a radicle will protrude and elongate from the seed (Odell’s World, n.d.). A radicle is a rootlet that sprouts from a corn seed as part of the growth process (Wright, 2017). The emergence of the radicle is known as germination, and it can take up to 3 days after planting.
However, the germination period can be delayed depending on different factors, such as soil temperature, moisture, the residue at the top of the soil, and the depth of planting (Wijewardana, Henry, Hock, & Reddy, 2016). The radicle grows downwards whereby many side branch roots occur. Another leaf, known as the embryo leaf, emerges from the seed and grows upwards before penetrating the soil surface. Upon exposure to sunlight, this leaf unrolls and becomes green in color.
Stage 2: Vegetative Growth
After the emergence from the ground, the corn plant continues to grow and elongate over the next weeks to form a stalk (also known as a stem). At the same time, growth also takes place under the soil whereby the root system continues to grow and penetrate the soil to create anchorage for the elongating stalk above the ground. After six weeks, the roots system is fully developed to supply the plant with water and minerals. Above the ground, the first leaf emerges after 4 days while a second one forms within 10 days (Wright, 2017). Between 10 to 20 days, the leaves can carry out photosynthesis, thus providing food for the plant.
Photosynthesis is the process through which leaves trap sunlight in their chlorophyll to make food. After the emergence of the fifth leaf, ear shoots start developing. The stalk continues to elongate and by the time ten leaves are formed, the tassel emerges and grows quickly. At the same time, cobs start forming at the base of the leaves. With time, the cobs reveal silky hairs from their tops.
Stage 3: Flowering
The tassel (a branched structure containing male flowers) forms at the apex of corn stalks (Sharpe, 2017). Tassels emerge three days before the formation of silks at the top of the cobs. The silky heads of the cobs are the female part of the corn plant. After ripening, pollen grains in tassels are shed onto the silky hairs of the cob for fertilization. In the late evening or early morning hours, wind shakes the tassels thus releasing pollen grains, which land on the silky hairs of the cob (Wright, 2017). Pollination continues for approximately two weeks. At this stage, each silky hair is expected to come into contact with at least one pollen grain for pollination and the subsequent development of the kernel.
Stage 4: Fruiting
Fertilization occurs within one day after pollen grains land on the silky hairs. This process leads to the formation of young kernels, which are known as blisters (Sharpe, 2017). Within each kernel, a plant embryo develops. In about 20 days after pollination, the milking process starts (Sharpe, 2017).
During this process, the embryo together with its kernel swells before turning yellow or white in color due to the accumulation of starch. In the next 7 days, the kernel reaches the doughty stage by entering its full size with enough moisture and starch content (Sharpe, 2017). Afterward, the kernels start to dry and ripen. On the outside, the silky hairs begin to dry and turn brown in color. At this stage, the tassel has already turned brown and it dries out. At the same time, the development of leaves also stops. This stage marks the maturity of the corn, and it takes around 60 days from the planting date.
Stage 5: Death
After the kernels in the cob mature, they start to dry followed by the degradation of the entire plant. If not harvested, the corn husks dry completely and they may fall away and release seeds to the ground for the lifecycle to start again.
Conclusion
The lifecycle of corn is a complex process that takes approximately 2 months. When the seed is planted, it germinates if the right conditions are available. The radicle grows downwards, while the embryo leaf progresses upwards and breaks the soil. In the second stage, vegetative growth is experienced whereby the root system is established to provide water and minerals while the leaves start producing food through photosynthesis.
At the flowering stage, the male part (tassel) forms three days before the emergence of silky hairs at the head of the cob. During fruiting, fertilization takes place when pollen grains from the tassel land on the female silky hairs thus leading to the formation of kernels. At maturity, all growth process stop, and the corn start dying to release seeds back to the soil for the lifecycle to restart.
References
Odell’s World. (N.d.). Corn growth stages. Web.
Sharpe, K. (2017). The lifecycle of a corn plant. Web.
Wijewardana, C., Henry, W. B., Hock, M. W., & Reddy, K. R. (2016). Growth and physiological trait variation among corn hybrids for cold tolerance. Canadian Journal of Plant Science, 96(4), 639-656.
Wright, J. J. (2017). The lifecycle of a corn plant. Web.