Plant Physiology and Growth

Within a plant, there are many physiological processes that are constantly occurring to allow the plant to grow and survive. Chemical reactions within the leaves produce sugar molecules through the process of photosynthesis which are needed by the plant for growing new cells and tissues. Plants are generally able to store food (so sugar) in their seeds, roots, stems or other parts, which indicates at the same time that the sugar molecules produced by the Quinoa plant are stored in the seed that is consumed. The seeds have a high protein content and are therefore considered as a very healthy food ingredient.

The Quinoa plant is part of the C3 plants, which means that it falls under the category of temperate or cool- season plants. In contrast to this, C4 plants are called tropical or warm season plants. The main difference of these two categories is that C3 plants reduce directly Co2 by the enzyme ribulose bisphosphate carboxylase in the chloroplast. Besides that, C3 plants usually provide a higher percentage of crude protein. On the other side, C4 plants are known for a more efficient gathering of carbon dioxide and utilizing nitrogen from the atmosphere. (Betts, n.d )

Quinoa is part of the annual species which means that the plants perform their entire life cycle from seed to flower to seed within one grown season. (E.A. Oelke, n.d ) In contrast to this, plants which are part of the perennial category persist for many growing seasons, where biennial plants require two years to complete their life cycle.

The vegetative growth of Quinoa varies between 150 to 240 days, depending on the environmental conditions in the specific region. This is the active growth phase where the plant acquires new properties to reach the vegetative maturity. In this phase the Quinoa seeds are not produced yet. On the other side the reproductive phase is the period where the plant will produce flowers and seeds to each physiological maturity. This phase is largely depending on the photoperiod sensibility of each variety where the duration of the stages can be modified, depending on the length of the day and the temperatures. (Didier Bazile, 2016)

The photoperiod sensibility of Quinoa is manifested from early stage of development up to the advanced stages of grain filling. Quinoas short day response to photoperiod means that the duration of some development stages is longer when plants are grown during longer days. However the Quinoa plant is able to reach flowering in all ranges of photoperiod explored. Therefore the capacity of Quinoa to respond to photoperiod changes is only affected after flowering stages. (Bertero, n.d )

Quinoa is not able to fix atmospheric nitrogen, as the nitrogen fixing bacteria are not present in the plant. In contrast to this, legumes are able to fix atmospheric nitrogen by making use of the bacteria present in the root nodules which convert atmospheric nitrogen to ammonium or nitrates which can be used by the plant. Due to this it could be recommend to apply crop rotation with legume varieties which enrich the soil and are beneficial for the environment and biodiversity.

References

Bertero, H. D. (n.d ). Section 2.1:Environmental control of development . Date accessed: November 2016 from FAO : http://www.fao.org/3/a-i4042e/i4042e08.pdf

Betts, D. L. (n.d ). What is the difference between c3 and c4 plants? . Date accessed  December 2016 von k- State Research and Extension : http://www.midway.k-state.edu/livestock/docs/What%20is%20the%20difference%20between%20C3%20plants%20and%20C4%20plants.pdf

Didier Bazile, C. P. (21. June 2016). Worldwide Evaluations of Quinoa: Preliminary Results from Post International Year of Quinoa FAO Projects in Nine Countries. Dte accessed: December 2016 from Frontiers in Plant Science : https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4914551/

E.A. Oelke, D. P. (n.d ). Quinoa . Date accessed: December 2016 from Alternative Field Crops Manual : https://hort.purdue.edu/newcrop/afcm/quinoa.html