Effect of light colors on growth of Monggo plants CHAPTER 1 Introduction A. Background of the Study Light is the form of energy visible that is radiated by moving charged particles. Light is made of electromagnetic vibrations which have wavelengths distributed evenly between 14 to 30 millionths of an inch. Light is very important in a plant's life. Without light a plant could not grow, reproduce, or produce food and building materials. So all plants would eventually die off if there was no light for them to use... Which, unfortunately, would lead to the eventual death of almost all life on earth. Color is the visual perceptual property corresponding in humans to the categories called red, green, blue and others. Color derives from the spectrum of light (distribution of light energy versus wavelength) interacting in the eye with the spectral sensitivities of the light receptors. See, sunlight contains many colors of the visible spectrum, and the invisible. Plant growth may be affected. The Mung Bean, or commonly known as Monggo Seeds or beans, are small and ovoid in shape. They are not expensive, and they are commonly used in experiments. This plant is a suitable test subject because of its fast germination period and because it is less expensive. Plants are primary food providers; they sit at the bottom of the food chain. They can harvest their energy almost primarily from the sun's rays. At first glance sunlight seems to be invisible to the eye but once it is analyzed sunlight is made up of a spectrum of colors. Varying degrees of these colors have different effects on plant growth. B. Statement of the Problem Main problem: Does the color of light affect the growth of Monggo plants? Sub-problems: 1) What are physical characteristics of the monggo plants when exposed to red light, in terms of: a. Leaf color b. Plant height c. No. of Leaves 2) What are physical characteristics of the monggo plants when exposed to blue light, in terms of: a. Leaf color b. Plant height c. No. of Leaves 3) What are physical characteristics of the monggo plants when exposed to yellow light, in terms of: a. Leaf color b. Plant height c. No. of Leaves 4) What are physical characteristics of the monggo plants when exposed to green light, in terms of: a. Leaf color b. Plant height c. No. of Leaves C. Hypotheses of the Study There will be no significant difference in the physical characteristics of monggo plants exposed to different colors of light D. Objectives The main objective of this study is to determine whether different colors of light hinder or aid in the growth of Monggo plants. E. Significance of the study The results of this study make people aware that different colors of light can really affect plant growth. The results of the study could suggest a more efficient way in farming but in small quantities due to the cost of the material used to change the color of light. F. Scope and Limitations The study focused mainly on the height of the plant, number of leaves, color of the leaves, at the end of a four-week observation period. Only forty seedlings of monggo are to be used. Ten seedlings every color. Although many plants might be used in this experiment, we prefer to use Monggo seeds because it is affordable and available on the market. It grows faster than any other seeds and will meet the deadline for the experiment. G. Definition of Terms 1. Monggo - Mungbean commonly called monggo, is the cheapest source of vegetable protein with protein content of 20-25 percent. It is an excellent crop for green manuring, because it matures early, grows fast and produces abundant vegetative tops. 2. Soil -The upper layer of earth in which plants grow, a black or dark brown material typically consisting of a mixture of organic remains, clay, and rock particles. Loam type. 3. Height - The measurement from base(soil) to top (top stem). 4. Leaf - A flattened structure of a higher plant, typically green and blade-like, that is attached to a stem directly or via a stalk. Leaves are the main organs of photosynthesis and transpiration 5. Red Light - light emitted through a red colored cellophane 6. Blue Light - light emitted through a blue colored cellophane 7. Yellow Light - light emitted through a yellow-colored cellophane 8. Green Light - light emitted through a green colored cellophane CHAPTER 2 Review of Related Literature ● Monggo The mung bean, in other languages, choroko (in Swahili), monggo, moong, moog (whole) or moog dal (split) (in Bengali, Marathi), munggo or monggo (in East Timor), is the seed of Vigna radiate. Mung beans are commonly used in Chinese cuisine and are generally eaten either whole (with or without skins) or as bean sprouts or used to make the dessert "green bean soup". The starch of mung beans is also extracted from them to make jellies and "transparent" or "cellophane" noodles. Mung Beans can germinate within 48-72 hrs. How fast they grow depends on the temperature, if they are growing in darkness or light, & if they have been soaked overnight before planting. "Within the temperatures that mung beans can germinate & grow, the higher the temperature, the better the mung beans will germinate & grow." http://en.wikipedia.org/wiki/Mung_bean http://www.usc.edu/CSSF/History/2004/Projects/J1631.pdf ● Light Three principal characteristics of light affect plant growth: quantity, quality, and duration. Quantity Light quantity refers to the intensity, or concentration, of sunlight. It varies with the seasons. The maximum amount of light is present in summer, and the minimum in winter. Up to a point, the more sunlight a plant receives, the greater its capacity for producing food via photosynthesis. You can manipulate light quantity to achieve different plant growth patterns. Increase light by surrounding plants with reflective materials, a white background, or supplemental lights. Decrease it by shading plants with cheesecloth or woven shade cloths. Quality Light quality refers to the color (wavelength) of light. Sunlight supplies the complete range of wavelengths and can be broken up by a prism into bands of red, orange, yellow, green, blue, indigo, and violet. Blue and red light, which plants absorb, have the greatest effect on plant growth. Blue light is responsible primarily for vegetative (leaf) growth. Red light, when combined with blue light, encourages flowering. Plants look green to us because they reflect, rather than absorb, green light. Knowing which light source to use is important for manipulating plant growth. For example, fluorescent (cool white) light is high in the blue wavelength. It encourages leafy growth and is excellent for starting seedlings. Incandescent light is high in the red or orange range, but generally produces too much heat to be a valuable light source for plants. Fluorescent growlights attempt to imitate sunlight with a mixture of red and blue wavelengths, but they are costly and generally no better than regular fluorescent lights. http://extension.oregonstate.edu/mg/botany/light.html ● Light Triggers Photosynthesis Plants require sunlight to produce food. Leaves are green because the pigment in them---called the chlorophyll---absorbs all other colors of light and reflects green light. When chlorophyll absorbs light energy, it triggers the photosynthesis process through which that light energy is converted into sugars. For the plant to grow, it needs to have this process operating at its prime, with the maximum amount of food being made to give the plant the fuel to grow. ● Sources of Light Natural sunlight has a lot of blue and red coloring in it, but these are imperceptible to the human eye. The plant uses blue wavelengths of light to create food for leaf production, and the red and orange wavelengths will encourage flowers. Plants most effectively use sunlight to grow. Fluorescent lights can be used to grow plants before they flower, since this lighting source is full of blue light. Red spectrum lights will encourage flowers to grow. Many incandescent light bulbs have red light, but heat from the bulb being placed too near the plant can cause damage. ● Rate of plant growth due to color of light Plants grow faster under certain colors of light. The reason for this is because chloroplasts can only absorb certain wavelengths of light because of the pigments they contain. There are 2 photo systems in plants called photo system I and II. PS I absorb light on the wavelength of 700nm while PS II absorbs 680nm because of their utilization of chlorophyll A and B. These two frequencies are known as the peak absorption points because they are the wavelength at which light is most strongly absorbed. Different forms of chlorophyll and other photosynthetic pigments absorb other other frequencies of light, but PS I and PS II are what is used for synthesizing ATP and reducing power which plants use to grow. The visible spectrum of light is between 380-750nm for humans. Therefore, PS I and II require red light to perform photosynthesis. As stated before, however, there are other photosynthetic pigments present in plants and other phototrophic species such as bacteria and algae that absorb other pigments. An example of this is the carotenoid pigment that absorbs primarily blue light as does chlorophyll A and B. Blue light contains more energy than red light but for PS I and II and plant growth both are needed. Studies in the 50's showed that the rate of photosynthesis increased under far-red and red light compared to other frequencies. http://wiki.answers.com/Q/Do_plants_grow_faster_under_certain_colors_of_light#ixzz1U9AczkLF ● Colors Absorption Natural sunlight gives off the entire light spectrum and offers plants what they need in terms of lighting. Blue lighting is most notable in summer and will encourage the plant to grow vegetation. Red and blue light combined as seen in spring encourages a plant to flower. A combination of other spectrum colors or dark light will see the plant grow leggy and sparse and eventually inhibit the plants ability to photosynthesize eventually killing the plant. Plants need a limited spectrum of at least blue or red light to thrive. ● Artificial Lighting Plants can be grown naturally outdoors in a sunny spot where they will receive full or partial sunlight during the day. Plants can also be grown indoors under artificial lighting. Metal halide bulbs produce blue light, which encourages growth. They are good for leafy plants such as salad greens and herbs. High pressure sodium bulbs produce red light, which encourages the plant to flower and fruit. These bulbs are good for flowers or fruiting plants. Growing plants indoors means the hours of sunlight can be manipulated achieving faster growth and out-of-season crops. Plants need light for three different processes. Phototropism is the plant's ability to move towards sunlight to maximize its sunlight uptake. Photoperiodism is the plant's reaction to the length of daylight it receives, which triggers the plant to flower at the appropriate time of year. The third process is photosynthesis which is the plant's ability to produce its own food by absorbing and converting the sun's energy into sugars. http://www.ehow.com/info_8038497_light-color-affecting-plant-growth.html#ixzz1U9Eex6Hd
