Background
Pigments in plants are what are responsible for color in plants, animals and all things. Pigments absorb some light waves, and the color that we see are the certain light waves that are not absorbed and instead reflected. The main pigment in plants is called chlorophyll A and B. These certain types of pigments are more dominant than any other pigment in a green plant, such as mung beans. During certain time of the years, different types of pigments are activated and the plants change colors, the leaves turn into colors such as red, yellow, and brown. Chlorophyll (the green colored pigment) absorbs both the red side of the spectrum (the longer wavelength), and blue side (the shorter wavelengths), but reflects the green part of the spectrum. This is shown in the chlorophyll/light absorption curve. The big dip in the middle of the spectrum represents both chlorophyll A and B’s non-absorption of that specific region of colored light. The reason for this drop is that the pigment doesn’t absorb the green wavelengths like it does with most of the other colors. Simply put, it reflects it. Some common types of pigments of light are chlorophyll, carotene, and xanthophyll. Each one of these pigments are responsible for a different type of color, respectively. Chlorophyll reflects shades of green, carotene reflects shades of orange, and xanthophyll reflects different shades of red and yellow. Plants grow by using a process called photosynthesis where light is absorbed by pigments and is converted into energy by going through a series of processes. Since light comes in different colors, different amounts of energy may be absorbed due to the dominant pigment in the plant.
Plants need certain conditions so that they can grow properly. Some of these conditions are temperature, water, oxygen, minerals, and light. All of these play a crucial role in the growth and health of a plant. The temperature of a plant varies on that species of plant and where it is growing. For example, warm seasonal vegetables will grow best when the temperature is between 60 and 70 degrees fahrenheit. Contrary to the warm seasonal vegetables, cool season vegetables will grow best while planted in environments with temperatures of 50 to 70 degrees fahrenheit. Water is another important part of plant growth. If there is not enough water, the plant will dry out in effect to this or on the contrary, if there is too much water, the plant could make for imbalanced plant growth, or potential death of the plant. Also, what kind of water the plant is being water with could affect the plant. For example, salt water could unevenly distribute nutrients, and softened water contains harmful amounts of sodium. The proper amount of water is always dependent on the plant and on the temperature of its environment. Both carbon dioxide and oxygen in plants are needed for the plant to function properly in the absorbing of the nutrients. Minerals are key to plant growth because without certain minerals, the plant will wither out and die. The minerals needed for keeping a plant healthy (in large amounts) are nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur. Likewise, the other nutrients needed (in small amounts) are iron, manganese, boron, zinc, copper, molybdenum, and chlorine. Finally, light. The reason for light being so important to the plant’s life is because without light, photosynthesis cannot happen, and without photosynthesis the plant cannot get the proper amount of energy to function, causing it to die. Different wavelengths of light have different amounts of energy too. Therefore a plant absorbing only red light wavelengths would not grow the same as one absorbing only blue wavelengths. There are some differences in the light that comes from the sun and the light that come from a light bulb. The energy emitted from the sun is greater than the energy emitted from a light bulb in the red and blue regions of the light spectrum. This means that the energy emitted from a light bulb in the form of a photon is not going to be able to give the plant the same amount of energy as the sun might in the field of light. However, different light bulb colors will give off different amounts of energy in different fields of light. Certain plants like certain light spectrum colors and because of this, certain plants grow differently than they would in a light that they don’t agree with. This experiment will test this theory and will find out what variables change the whole of the plant growth. Throughout the experiment, we will be testing different colors of light on the same plant in the same environment and we will measure their growth to prove this theory.
This theory also has real world applications because people could be able to create farms without sunlight, meaning less land consumption, and this could make thier plants/crops bigger, faster. We wouldn’t have to eat those harmful GMOs anymore or use chemicals to grow our crops, as a result of the effect the light will have on the plants. This is a safe and environmentally friendly way to potentially get food faster and in a healthy way, so our future generations will again love the fruits and vegetables put on the dinner table every night. In this experiment, we will also test the theory that different wavelengths of light can increase the rate of the mung bean growth. Producing more amounts of food without needing an extra amount of sunlight would be extremely helpful to us because of global warming. It is getting harder and harder for plants to survive outside because of heat and the roots of plants drying and dying so we should bring them inside and have them grow faster. We will house these plants in an environment with no external light, only our colored lights, so that our results will be the most accurate possible.