CHAPTER I INTRODUCTION A. Background of the Study Philippines is an agricultural country. The geographical location of this country in the Tropic plays the major role to this fact. Aside from rice, Filipinos produce most of the crops that they use to make food that they serve in their dining tables. In the countryside, houses have different kinds of vegetables, fruits and root crops planted on their backyards. Because of this, majority of families in the countryside just pick their dishes from these plants. Philippines has been going through the industrialization process of social and economic change. It is a part of a wider modernization process where social change and economic development are closely related with technological innovation, particularly with the development of large-scale energy and metallurgy production. CEA (controlled-environment agriculture) is any agricultural technology that enables the grower to manipulate a crop's environment to the desired conditions. Philippines can use this kind of agriculture to use as an advantage of being an agricultural country. In most urbanized areas, houses do not have a permanent place that sunlight can pass through. There are a few plants that will grow with only one light in a windowless office or a one-room apartment whose single window faces into an air shaft. (House Plants, 1975) Artificial lighting is the answer for almost any kind of plant that can be grown if enough artificial light is provided, even in situations where no other light is available. Artificial lights allow regular people to plant whole gardens in places where no plant would ordinarily grow. Sunlight is a mixture of all visible wavelengths of light and if it hits the plants the pigments of the plants can absorb or reflect the selected wavelength. The researchers would like to know if separating each color and making it the only light it will have, would have an effect on the plant’s growth This study aimed to find a significant difference in the sprouting of a mongo plant when exposed to different colors of light specifically red, orange, yellow, green, blue, violet and white. In this case, the researchers chose the mongo plant since it grows quickly and the researchers can quickly gather the needed data immediately. A lesson in Biology I (You and the Natural World: Biology, p.107) on Chapter 7, Cell Metabolism-Energy and Photosynthesis stated that “chlorophyll absorbs most red, orange, blue, and violet light. It reflects green and yellow light, giving its body a green coloring”. This statement got the researchers curious and wondered if plants act differently to the green and yellow colors of light, then they should have different reactions and effects to every color of light. The researchers decided to pursue this study to determine whether plants have different reactions to different colors of light and identify these reactions individually. B. Statement of the Problem This study will determine and compare the effect of different colors of light on the growth of mongo plants. Sub-Problems: 1) What is the growth of the mongo plants exposed to different colors of light in terms of: a. Onset of true leaf b. Number of leaves c. Sprout height d. Biomass 2) Is there a difference between the growths of the experimental plants in each set-up in terms on onset of true leaf, number of leaves, sprout height and biomass? 3) Is there a difference between the growth of the controlled plant and the experimental plant in terms on onset of true leaf, number of leaves, sprout height and biomass? 4) Which color of light would be the best for the plant’s to grow? C. Hypothesis 1) There are different results because they are exposed to different colors of light. 2) There is difference between the controlled set-up is exposed to sunlight which has colors red, orange, yellow, green, blue and violet while the experimental set-ups are only exposed to one color. 3) There is a difference between the growths of the plants in each set-up. During the photosynthesis, colors yellow and green are reflected by the chlorophyll which means that the plants react differently to different colors of light. 4) The color red or blue is the best for the plant’s growth since this color. The colors orange, yellow and green don’t have any effects on the plant’s growth. D. Objectives of the Study This study aims to assess the growth of a mongo plant when exposed to different colors of light specifically red, yellow, green, blue, and white and verify if there is a significant difference. Furthermore, it aims to determine the best color of artificial light in growing mongo plants in terms of onset of true leaf, number of leaves, sprout height, and biomass D. Significance of the Study This study determines which color of light can give a better effect to the sprouting growth of mongo plants. This study improves CEA by minimizing the expenses but still having the same results. Using CEA in the Philippines’ agriculture could cause great improvements to the economy. Common housewives that like gardening inside their house can benefit from this study. Artificial lighting is useful when natural window light is insufficient. They make it possible to grow healthy plants in any spot in the house. They could plant flowering plants inside their home and make it as an alternative decoration or they could rather plant vegetable gardens and fruit trees in their backyard or just on pots to save money in preparing food. The results of this study could also help gardeners make plants grow healthier and flower abundantly. Businessmen more specifically flower shop owners could introduce artificial lighting to their gardens to sell beautiful flowers for their shops. Farmers could apply artificial lighting in their farms to industrialize their agriculture. This could help them produce fine rice, crops, fruits, vegetables and etc. E. Scope and Limitations This study is only limited to the determination of the effect of the different colors of light such as red, orange, yellow, green, blue and violet on the growth of the mongo plant (Vigna radiata) in terms of a) onset of true leaf, b) number of leaves, e) sprout height and f) biomass. The differences must be recorded in each pot of plant. There would be three pots assigned to a single color. By using different colors of light, the researchers can determine the light that can give a better effect to the sprouting growth of the mongo plant. Since mongo plant grows in a short span of time, the researchers can record and gather the information and data that they need. F. Definition of Terms Mongo Plant (Vigna Radiata) It Is the test subject. Used to determine if different color of light can affect its growth Plant Growth The basis of comparison for the researchers to distinguish which of the different color of light can be best for the plant’s growth. Factors to be compared are onset of true leaf, number of leaves, sprout height, and biomass. Colors of light Colors to be use are red, yellow, green, blue, and white. This will serve as the only light that the plant can have during growing process. Experimental group The group that is given a special treatment. In this study, the experimental group is the pot of plants that is given one different color of light. Controlled group The group that is not given any special treatment. In this study, the experimental group is the pot of plants that is exposed to the sunlight. Onset of true leaf the particular time that leaves may appear during photosynthesis using the artificial lights. Number of leaves the total number of leaves of the mongo plant after the investigation Sprout height height of the mongo plant after the investigation Biomass the mass of the mongo plant after the experimentation CHAPTER II REVIEW OF RELATED LITERATURE AND RELATED STUDIES According to Andrew Zimmerman Jones (1991), visible light spectrum is the section of the electromagnetic spectrum that can be seen by the human eye. It is also known as the optical spectrum of light with wavelength ranging from approximately 400 mm to 700 mm. The perceived color is dependent on the wavelength of the light. We actually interact with light in the form of white light which contains many or all of these wavelength ranges within them. When shining white light passes through a prism causes the wavelength to bend at slightly varying angles due to optical refraction. Therefore, the resulting light is split across the visible color spectrum. This results to rainbow characterized by airborne water particles acting as the refractive medium. The order of wavelength is best remembered by “Roy G Biv for Red, Orange, yellow, green, Blue, Indigo and violet. (http://physics.about.com/od/lightoptics/a/vislightspec.htm) When sunlight strikes the leaves of a plant, the light-wave energy is absorbed by the chlorophyll. The chlorophyll absorbs most red, orange, blue, and violet light. It reflects green and yellow, giving its body a green coloring (You and the Natural World, p.107). This means that plants react differently to different colors of light. With this in mind, artificial light was considered in this study. Artificial lighting is any lighting that is not sunlight. Generally speaking, artificial lighting is lighting which is man made, such as fluorescent, tungsten, mercury vapor, sodium vapor, halogen, compact fluorescent, et cetera. It can be turned on and off at a flick of a switch. There are also very special types of artificial light for specific purposes like infrared heat lamps, ultraviolet lights for plant growth http://wiki.answers.com/Q/What_is_artificial_lighting). The researchers would use colors red, blue, green, yellow and white as basis for the colors of the light bulbs in conducting this study. Natural daylight from the blue part of the spectrum is optimum for the initial stage of plant growth. Artificial light will work almost as well--fluorescent, incandescent, LED or high-intensity discharge lamps (like metal halide or high pressure sodium) as stated in the study “The Effect of Light on Plant Growth”. High intensity discharge lamps offer the best indoor lighting option, allowing for a controlled environment with faster production and quick growth from seed. (http://www.ehow.com/about_5251025_effect-lightplant-growth.html) Mung bean is commonly known in the Philippines as munggo or monggo is the seed of vigna radiata which is native to India. These beans are small, ovoid in shape and green in color. Mung bean seeds are either sprouted for fresh use or canned for shipment to restaurants. The sprouts are high in protein about 21-28%, calcium, phosphorus and certain vitamins. Because these beans can easily be digested it can replace scarce animal protein in our diet. Due to its major use as sprout, a high quality seed with excellent germination is required. The food industry prefers about 9-10 grams of fresh sprout for each gram of seed. Larger seed characterized with glassy and green color is oftentimes a preference. In mung bean, both upright and vine type of growth habit occur with plants varying from one to five feet in length. The pale yellow flowers are borne in clusters of 12–15 near the top of the plant. Mature pods are variable in color (yellowish-brown to black), about five inches long, and contain 10 to 15 seeds. Mungbeans grow best on fertile sandy, loam soils with good internal drainage; their growth is poor on heavy soils with poor drainage. Every transformation is an energy that occurs at the cellular and molecular levels. In cells, there are two basic patterns by which organisms transform energy, the autotrophic and heterotrophic pattern. In autotrophic cells, light energy is transformed to chemical energy that can be used by cells. Green plants contain this type of cell. Photosynthesis is a process by which living plant cells combine carbon dioxide and water in the presence of chlorophyll and light energy (You and the Natural World: Biology, Chapter 7, Cell Metabolism-Energy and Photosynthesis, p.107). The light excites the electrons to receive NADP and also splits water into oxygen and hydrogen. The light is the primary key to photosynthesis. Cold frames are less expensive than greenhouses, take up less space and are cheaper to keep warm. Their main disadvantage is that the gardener works outside and not inside in the warm and dry as with a greenhouse. In the vegetable garden, cold frames are frequently used for producing winter or early crops of such vegetables as carrots. The frame can be in a permanent position in the garden or moved, rather like a large cloche, onto the vegetable bed itself. The vegetables can be grown either directly in the soil or in growing bags. Another basic use is to afford protection and warmth to trays of seeds or seedlings. (http://mangorevolution.com/98/house- home/gardening/building-and-using-cold-frames-in-your-vegetable-garden) The researchers’ study relates to the study titled ‘The Effect of Different Genres of Music to Mongo Plant’s Growth’ by Generev Zerna Jungao and Rhoie Jhannarie Omlero which also determines the significant difference in plants’ growth but only using genres of music instead of colors of light. The researchers of the study aimed to know the best genre of music for growing plants by exposing mongo plants to a genre of music changed weekly, the first week was classical music, second week was jazz, third week was pop and the last was rock. The study concluded that jazz is the best and rock music was not good for plants. In a study on “The Effect of Short-Wavelength Light on Plant Physiology” the cultivation of lettuce and radish was experimented using different combinations of red and short-wavelength components and high pressure sodium lamps and it was found out that red and blue components are favorable for growth and nutritional quality of lettuce. The most striking sensitivity to illumination spectrum was observed for production of carbohydrates. In respect to the reference plants, content of nitrates in lettuce grown under the bicomponent illumination in red and short wavelength regions was by 15-20% lower with no significant difference among treatments where the shortwavelength was cyan, blue or UV. The results of this study confirmed that plant growth can be modulated by employing tailored spectrum provided by emission of different LEDs. Even illumination with spectrum consisting of two (2) components (one in red region and another in short-wavelength region) when properly selected can be beneficial in respect to illumination using conventional lamps. (http://www.lightinglab.fi/enlighten/publications/internetui_akvile.pdf In the study “Plant Growth Factors: Light”, states “light quality refers to the color or wavelength reaching the plant's surface. A prism (or raindrops) can divide sunlight into respective colors of red, orange, yellow, green, blue, indigo and violet.” The study also concluded that blue light is considered to be the primary responsible for vegetative leaf growth while red light encourages flowering. (http://cmg.colostate.edu/gardennotes/142.pdf) Synthesis In this research, significant differences between the growths of mongo plants exposed to different colors of light is observed. The researchers will monitor the growth of the plants exposed to artificial light from the very beginning of the growth stage; seeds, to sprouts, and to full grown plants. The researchers will observe and record significant differences between each plant to determine the important effects of different colors of light to plant growth. From the different related studies, the researchers have gathered different ideas. It is possible that the blue and red colors can greatly affect the growth of a plant. A study says that blue is responsible for leaf growth and red develops flowering. This study is somehow similar to the study ‘The Effects of Different Genre of Music to Mongo Plants Growth’ since both observe the significant differences of plant growth when exposed to different factors. This study focuses on the effects of colors of light while the other focuses on effects of genres of music. Also, the researchers of the other study used the same samples for the different treatments; they exposed the same mongo plants to different genres of music which is changed weekly. This study aims to determine the significant difference of the effects colors of light to plant growth at the same time. CHAPTER III METHODOLOGY A. Research Design This study aims to determine the best color of light for growing plants by comparing the growth of mongo from seeds to sprouts and to a plant which is exposed to different colors of lights. To attain this, the researchers would use two groups, the controlled group where a plant would only be exposed to sunlight and the experimental group where artificial lights would be used as an alternative for sunlight. The artificial lights in this study has variations of colors such as colors red, orange, yellow, green, blue, violet, and white. A plant would be exposed just to a single color throughout this whole study. Since this study is concerned about the significant effects of a color of light to a growing plant, the researchers would observe the growth of the mongo plant weekly from the very beginning of the experiment. Extraneous variables or factors that could affect on the behaviour of the subject being studied such as amount of water or intensity of light should be strictly maintained to be able to get the desired data from this investigation. All subjects would be watered everyday by 500mL of water. The plants from the experimental and controlled group would be exposed to the light for only six to eight hours per day for four weeks. B. Materials and Equipments: Materials Equipment soil 5 water cellophanes (red, yellow, green, blue, and white) water 6 cold frames ½ or 1 kilo of mongo seeds measuring cups 6 big sacks or cloth popsicle sticks 6 pots C. General Procedures: Preparation of Materials The flower pots would be filled with loam soil. Loam soil is an equal mix or sand, silt, and clay. Loam can make the plants grow healthier. Soil should be equal in every pot so that it won’t affect the subject materials or the factor that is being tested. Every sack should be divided into six equal parts. The sacks will be assigned to specific colors of light. The sacks will be used as the place for the seeds to grow into a sprout. The cold frames should have holes at the side; the holes will serve as the entrance of air for the plants to breathe. Each cold frame would have different colored water cellophanes: red, yellow, green, blue and white. The last frame would be assigned to the controlled group which doesn’t have any light. Preparation of Set-up a. Seeds Prepare the sacks; one sack should be assigned to a particular color of light. Pick ten mongo seeds for each sack which means there should be sixty mongo seeds for the five colors (red, blue, green, yellow and white) of light and sunlight. Lay 10 seeds on top of each sack. Water the seeds. Observe them for the whole day until they grow into sprouts. b. Sprout When the seeds grow and become sprouts, the researchers will transfer them into to pots. There should be exact distance between the seeds, approximately four inches away from one another to let the plants breathe when they grow. Remember that when the sprouts were still seeds, they were already assigned and exposed to different colors of light that is why the assignments of colors will still be the same. Each pot will be put into a cold frame. Each frame will be assigned to a specific color of light according to the previous assignments. Exposure to Treatment There should be one color assigned to each cold frame. And since the frames vary in color, every set-up should be unique and different from one another. Cellophanes should be attached on top of each frame so that when the light passes through, another color of light will appear. In the 6 frames, holes should be at least at one side to give plants natural air from the environment. Since there are only five water cellophanes, put the remaining cold frame without water cellophane in a spot where it can receive enough sunlight. Monitoring of Growth Now that the preparation for the set-up for this study is done, the next thing to do is to take care of the plants. All the subject materials should be watered everyday equally with 500mL with water daily. The plants should be exposed to light for only six to eight hours a day. a. Seed The researchers would observe the onset of true leaf and the number of sprouts that grew for each color assignment. The first three mongo plant that would grow corresponds to the three trials. These three mongo sprouts would be further observed for other characteristics. b. Sprout The researchers would observe the number of leaves, onset of true flower, number of flowers, and sprout height, at the end of each week. The biomass at the end of the experimentation would be measured. For the sprout height, popsicle sticks will be stuck on the soil beside each mongo plant sample where markings of weekly height level will be marked so as not to disturbed plant growth while measuring their height. The popsicle sticks would then be removed at the end of experimentation and each markings per week be recorded. E. Procedures/Instrument in Data Gathering The researchers would conduct observations and record significant differences between the seven set-ups every week in corresponding tables shown below. Example: Seeds Table # 1 Number of Sprouts & Onset of True Leaf Number of Onset of True sprouts Leaf Light (hours) Exposed T1 T2 T3 Tave T1 T2 T3 Tav e Red Yellow Green Blue White Sunlight Sprouts Table # Characteristic of Mongo Plants Number of Leaves Sprout Height Light (piece) (cm) Exposed T1 T2 T3 Tave T1 T2 T3 Tave Red Yellow Green Blue White Sunlight F. Biomass (g/unit area) T1 T2 T3 Tave Statistical Tools for Data Analysis The data that will be gathered will be analyzed and interpreted using appropriate tools. The average will be used to declare results of various parameters such as number of leaves, number of flowers, and sprout height. ANOVA will be used in order to know if there is a significant difference among results. FLOWCHART a. Seeds Prepare the sacks and assign colors. Pick 10 seeds for each treatment. Lay seeds on top of each cloth; expose seeds to artificial light. Water the seeds, observe until seeds grow into sprouts. b. Sprouts Transfer the sprouts into pots. Enclose each pot into a cold frame Monitor growth, water the plants with 500mL of water everyday Sunlight will change in color when passing in the frames glass. Assign colors to each frame according to the previous assignment. Put water cellophanes into each frame.