Techniques in crop management
By Rafael Pérez Vicente
July 24, 2022
UPDATED 12:00 PM EST
Since the beginning of times humankind has had one important concern regarding their safety and survival: food. Initially they thought that hunting and gathering would be a sustainable approach. However, they quickly came to realise that this didn´t ensure sufficient resources for everyone. Humans drifted onto gardening and domestication of animals to obtain resources, and with that emerged new technologies of crop and plant management.
Thriving to obtain healthy and adapted seeds for the environment to grow rapidly became an issue. As populations couldn´t control plagues, health and evolutionary path at the time. Nevetheless, techniques that helped to fight off this problems emeged with the second industrial revolution. As mass production and population growth spiked, the need for growing at faster and greater rates was one of the main targets for agricultural specialization.
Stemcuttings was one of the first techniques that emerged with the purpose of rapid propagation and cloning of species; obtaning organisms with no genetic diversity among each other. This agricultural technique consists on the “cutting” of a plant shoot (technical name for stem), where undifferentiated nodes of cells exist within the fragment; with the purpose of making them differentiate by providing specific conditions in temperature, humidity, light and CO2 concentrations.
This propagation method has allowed agriculturers to obtain new sprouts of the same plant with the same genetic information over and over. However, the it still has a few disadvantages. As an asexual and artificial form of reproduction, stemcuttings do not provide genetic diversity which makes them more susceptible to changes in the environment such as droughts, infections, plagues, etc. Additionally, cloning plants by stemcuttings usually makes rooting slower and greater chance of crop failure due to a lack of propagation, and usually artificial forms of rooting hormones such as auxins are needed.
On the other hand, micropropagation, a fairly recent form of plant reproduction in mass has been very promising for commercial horticulture. Also known as tissue culture, this technique allows scientists and farmers to grow in a larger scale and lesser volume multiple plants. The process involves a lab, which means that the plants are grown invitro (outside their normal and natural conditions in the environment). And it allows individuals to clone and reproduce plants with desired characteristics to induce genetic convergence onto advantageous traits such as fruit production, plague resistance, water intake, etc.
Tissue culture is done in a sterile environment where small cuttings from the apex or other undifferentiated parts of the plant are selected to be grown in agar gel. This gel contains nutrients, water, and important hormones such as auxins, gibberlins and cytokinins. It provides all the necessary conditions for the clump of cells in the test tube to differentiate and grow into a larger clump called a callus. Which then differentiates further and adopts a smaller plant form. This, can then be transferred into potting soil and grown as an ordinary crop.
Micropropagation still has a few disadvantages regarding its use. As not all plants can be micropropagated practically and growing at the lab is fairly expensive. However, the course for this agricultural process still has a long way to go.
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