The purpose of our student generated lab is to determine, through research and experimentation, what kind of liquid food source is best suited for a plant and what will make it grow the fastest and healthiest. The problem we are investigating is whether or not the use of lemon-lime Gatorade will affect the plant’s growth and health in a negative or positive way when compared with the use of Brita filtered water and tap water. Tap water will be our constant while the other two will serve as the varying food sources. We chose to do this experiment that focused on Gatorade as a variable food source because we were curious as to the effects Gatorade would have on a plant. Even though the human body is 60% water and needs water to survive, Gatorade has been proven to have a more positive replenishing and nourishing effect to active humans than water (Beck 1). Since we knew that Gatorade has been proven to replenish electrolytes and nutrient levels within human athletes during activity, we thought that maybe it would have a notable effect on plants as well. However, we think that this notable effect will be a negative one due to the sugar and salt contents of Gatorade. Our hypothesis is that the plants watered with the tap water will be most successful and the Brita filtered water following, while we believe the plants watered with Gatorade will become flaccid. We chose to use Marigolds as our choice of plant since “After they're up, marigolds demand very little attention,”(Smittle 54) and since marigolds germinate and bloom fairly quickly and they “are one of the best annuals for growing indoors during the winter”(Winterrowd 50). Marigolds seem to be the easiest and best plants to use for this experiment since they thrive when watered “for longer periods at a time but less frequently”(Cardillo 14). We decided on this type of lab involving plants because we thought it would be interesting to find out what affects the Gatorade and different types of water sources had on the marigolds. We plan to discover the best way to feed a plant and how important the source of food is that plants are given.
In order for our plants to grow, they must obtain the essential nutrients needed for growth. “Sixteen chemical elements are known to be important to a plant's growth and survival. The sixteen chemical elements are divided into two main groups: non-mineral and mineral”(NCDA&CS, np). The non-mineral group consists of hydrogen, oxygen, and carbon. These nutrients are all obtained through the air by the plant, so there is little that can be done to regulate these. The mineral group is divided into 2 sub-categories: macronutrients and micronutrients. The macro category is then divided again in two: primary and secondary. The primary nutrients are nitrogen—which is essential in synthesis and in the transfer of energy, phosphorus—which is an important part of photosynthesis and it supports blooming and root growth, and potassium—which helps in the building of proteins and helps fruit quality. The secondary category consists of calcium—essential part of the plant cell wall structure, magnesium—helps to activate certain plant enzymes that are used in growth, and sulfur—improves root growth and seed production. The micronutrients needed for healthy plants are copper—important in reproductive growth, iron, chlorine, manganese, boron—vital for seed development, molybdenum, and zinc (Jobbagy np).
One important aspect to look at when conducting this experiment is osmosis. “Osmosis is the passage of water from a region of high water concentration through a semi-permeable membrane to a region of low water concentration”( Purchon, np). During osmosis, plant cells take on water, causing them to swell. This in turn makes them turgid, or rigid. Yet, because the wall of a plant cell is thick, the cells do not burst. This turgidity is very important in plants because it helps them to remain upright. This is why when a plant is dehydrated or deprived of water, it begins to wilt because there is no swelling in the cells to hold the plant in a “standing” position. This information will be important to keep in mind when observing and taking records of how our plants react to the different stimuli.
Many other experiments have been done in this fashion to gain a higher understanding of the effects of nutrient availability and food intake on vegetative growth. These experiments that test plant’s reactions to different stimuli have been recorded and put to use over the generations for many different areas. Some use this information for agricultural and therefore economic purposes, and some use this information for things like medicine. One important reason to test the effects of nutrient availability is to find out its effect on reproductive processes. One journal, Oecologia, by Alejandro Munoz did a study on the effects of nutrient availability on flower production to understand how it affected the plant and its proceeding generations:
Soil nutrient availability directly enhances vegetative growth, flowering, and fruiting in alpine ecosystems…Enhanced nutrient availability in the alpine ecosystem can also affect reproductive processes. Increased soil nutrient availability can result in the allocation of additional resources to greater fruit and see production or to the maturation of existing fruits, thereby reducing levels of seed abortion (Munoz np).
By testing different stimuli, such as Gatorade or purified water, one can begin to understand what elements are needed to increase or decrease nutrient availability in order to tailor to a specific plant and enhance growth and reproduction. Some plants are stifled by the presence of too much nitrogen or fail with the lack of oxygen (Van Bodegom np). With information of this kind and other journals and experiments like it, we will be better able to mold our experiment after these and have more knowledge to therefore interpret our results. After researching these journals and reading about other scientists conducting these experiments, our group and others to come will have a better grasp on the situations/conditions needed in order to have the most successful outcomes. Another factor that was included in one of the journals concerned light availability. Seedling plants were affected by increased amount of photosynthetic daily light integral (DLI) flowered earlier, but the quality of the plant was reduced (Pramuk np). This information is critical to our experiment and to groups such as agricultural farmers as it pertains to knowledge in how to create the most successful crops. In general, there have been many experiments that test the effects of different stimuli to plant growth. Very closely related to our experiment, was one such experiment found in Plant Physiology and Biochemistry where the scientists tested the effect of salinity on marigolds. Their results concluded that;
Salinity can affect growth and yield of most crops; high salinity is known to cause both hyperionic and hyperosmotic effects in plants, leading to membrane disorganization, increase in activated oxygen species production and metabolic toxicity…Antioxidant resistance mechanisms may provide a strategy to enhance salt tolerance. Achieving a selection of genetically transformed salt tolerant plants is possible, once the mechanisms of salt effects and of the antioxidative responses of plants are identified. Despite the large body of literature on salt stress, to our knowledge little is known about the effects of salinity on this plant. Therefore there is a pressing need to know more in detail how an important economic plant as marigold responds and adapts to such conditions
This information makes it evident that experiments such as this and own our modified version of it are necessary and important to the scientific and even economic world. Knowing this information of how certain elements or environments affect the growth of plants such as marigolds allows scientists to control and influence these environments to their advantage. By reading these journals of other renowned scientists allows us to better understand the effects that different stimuli and conditions will have on our marigolds.
Materials and Methods:
In this lab, we will explore the effects of different hydration options for marigolds. The three hydration options we will be using are Peabody Hall tap water (control), Brita purified water, and Lemon-Lime Gatorade. Each of these water-alternatives will be tested on 30 marigolds, 10 per hydration method, each in their own ‘flowerpot’, ie plastic cup. To begin the experiment, each cup must be filled with 500 mL of soil. The marigolds should be planted Ļ inch into the soil in the center of the cup. Once planted, each cup should be labeled with a number (1 through 30) and the type of hydration it will be subjected to (Gatorade, Brita or Tap). After being planted and labeled, the cups will be placed in a greenhouse for safe and consistent keeping. The marigolds should be watered daily for the first 10-12 days with 100 mL of fluid (Cox, 2). For the days following the first 12, the marigolds will continue to be watered with 100 mL of liquid three times a week on Tuesday, Thursday and Saturday.
Each day, before watering the plants, the data sheet will be filled out. In order to maintain a statistically sound report, the data sheet consists mainly of numeric observations. The height of the plant, a leaf count, bud count, flower count, and measurement of leaf sizes will be conducted. Also, we will note the color intensity of the plant as well as the thickness. Finally, we will consider the moistness of the pot each day, deciding whether the amount of fluid we are providing is a good amount, too little or too much. Every Friday, we will photograph each plant individually and keep copies so that we will be able to explain the progress visually. We will maintain records by use of the data sheets and pictures taken from each observation period to be able to chart growth and development for final analysis. One last observation we will make is of the plants’ biomass at the end of the experiment. We will dry the plants out and weigh them to gain another concrete measurement of growth. We will include these weights and comparisons in the final analysis.
Originally, we considered using water from the Peabody water fountains as well as creek water from Peffer Park, however, decided against it because we believe that it would be a waste of time and supplies, yielding similar results as the tap water control. We chose to use tap water as a control because it is a very common source of hydration for people growing plants at their home. Since it is the most common source, it is known to be helpful to the plant’s growth but it is unknown whether it is the best option. The Brita water was chosen because it is advertised as “pure” implying that pure is better. Since ‘pure’ is considered to be healthier than tap water, we wish to test whether that is also the case in plants. In people, Gatorade replenishes more nutrients than water alone such as electrolytes (i.e salt), sugar, and potassium (The Science of Hydration np). Since these things seem to help people maintain good health, we wish to test, again, if this is the case in plants. In choosing a plant, we considered using tomato plants and green bean plants but decided that they would not be the best option for keeping data. Tomato plants may grow to be too large and we did not have much information concerning green beans so we chose to use a common flowering plant that would be easy for all people to identify with.
In order to maintain unbiased and consistent results, we will set a standard on what is “thick” and what is “intense” for each color. We will also be sure to have at least one person from the previous visit present so that the comparison will be in relation to the last. The rest of our measurements are numeric and so the data is quantifiable and statistically sound. Measurements will be done in metric using centimeters and ounces.
To conduct this experiment we are using 30 cups, 10 cm in diameter, 12 cm high. The soil is Miracle Gro and we will use 500 mL to fill each cup. The soil is pre-fertilized, so it will help to induce plant growth and encourage speedy germination (Miracle Grow Potting Mix np). The plants are American Seed brand seeds: Marigold, French Dwarf Double Mixed Colors. We will plant one seed per pot. The hydration sources are Lemon-Lime Gatorade from a 64-ounce container, Peabody Hall tap water from the second-floor South bathroom and Brita purified water. We will use a standard ruler with centimeters to measure the height of the plant. Otherwise, our data will come from our own abilities, counting and judging color and thickness.
Other options for conducting this experiment involve changing some of the factors and variables. We chose to use marigolds but someone may wish to conduct this experiment with another type of plant with different growth patterns and more observable traits. The easiest factor to change would be what it used to water/ ‘feed’ the plants. Although we chose to use Gatorade, tap water and Brita water, there are other stimuli that would affect plant growth differently. Some viable options could possibly be using pop because of its high sugar concentration, salt water because of its salt content, or red bull to test the effects of caffeine. These would be good options because each of these stimuli affects difference aspects of the plant and be an alternate to water.
To determine whether or not the plants that are being observed are healthy and successful, our experiment requires a regimented list of quantifiable data. In order to determine whether the plant is growing consistent with its feeding schedule or if it is spoiling, one must, “Avoid plants with dead, discolored or misshapen leaves. Yellow foliage may mean the plant has been over- or under watered. Foliage with a purple cast may signal cold damage” (Stoll, Online Journal). Leaves, however, are not the only signs of strength; the roots that grow beneath institute a sturdy base for all of the plant’s expansion. Another journal that focused on determining healthy plant growth stated, “…Healthy plants also have a healthy root system, which should be white and fibrous” (Bien, Online Journal). From the steady roots comes increase in bud count, thickness, plant height, leaf size, and color.
In order to distinguish what Marigold flower plant generates into the most vigorous plant, we have previously stated that our lab group is planning on measuring the plant height, leaf count, leaf size, bud count, flower count, plant color, and finally, thickness of the root base. An Internet site provided important data on how to measure each category. In order to capture every characteristic of each plant, techniques will include tracing an outline of each leaf on paper to record the augmentation. Counting of how many leaves grow will take place each recording date as well as the height from the base of the pot used for each Marigold. Finally, it is important that the group documents any noticeable color change. (Hess, Internet) The process of documentation will provide the most vital information to the project, so it is chief to remember to take all data carefully and make sure that it is precise.
It is important to realize that a table has already been established to keep track of all measurements that are recorded every Tuesday, Thursday, and Saturday of each week. All data and information dealing with the growth of the Marigolds will have to be reported in table or graph status to create a visual effect while explaining the process. Also, t-tests will be implemented to compare the biomass measurements of the three different plants with separate hydration methods. One t-test will be between tap water and Gatorade, the other between tap water and purified water. These two t-tests will compare the biomass measurements taken of all the plants and will show how the different hydration methods are related to each other and how similar they are.
As stated previously, since plants are most often watered with tap water, we chose to make this hydration method our control. As the weeks passed, it became clear why tap water is so frequently used to water plants because it proved to be very effective in the plants’ growth and was a cheap, convenient food source. Within the first week of watering six out of the ten plants hydrated with tap water had sprouted. Although small in size, these sprouts showed much growth for a period of one week’s time and the soil remained moist. In the second week all ten of the plants had sprouted and begun to grow small green leaves (refer to figure 2). On average the tap water plants had a height of about one inch in the second week. In the third week of watering the plants with tap water all the plants had grown about another half an inch and had about 5 or 6 leaves. In the fourth week of watering the plants were a vibrant green and looked very healthy, measuring about 2 to 2 1/2 inches with many leaves. During the sixth week of the experiment the average height of the plants were about 3 1/2 inches and the leaf count was around a hundred and by the end of week 6 the leaf count of the plants was over 140. In that sixth and final week of the experiment the tap watered plants were all healthy and green with buds and two of the plants had even bloomed (See Results Page for specific statistics). All of the tap watered plants contained healthy, extensive root systems that coiled around the bottom of the cup, suggesting a desire for deeper growing space (See Figure 5). The lengths of the roots were about two times as big as the height of the plants (See Figure 6). After drying and weighing the tap water hydrated plants, the masses ranged from .381g to .875g and averaged a mass of .6379g (See Plant Weights page).
The second set of marigolds was hydrated with Brita filtered water. During the first week of watering, seven out of the ten plants watered with Brita had sprouted (refer to figure 1). Within the second week, all of the ten plants in this set had sprouted and had small, green leaves. The third week of the experiment, the average height of the plants watered with Brita filtered water was 1.75 inches with a leaf count of about 32 leaves. In the fourth week of the experiment all of the plants looked healthy and very green with a height of around 2 inches. In the sixth week of the experiment the plants had grown between 3 and 4 inches with an average leaf count of over 140 leaves. In the sixth and final week of the experiment, the plants watered with Brita filtered water were all large and healthy with a few plants in bloom (See Results Page). The Brita plants also had extensive and healthy root systems just as was found in the tap water plants; white with a main tap root with many root hairs branching off (Fig 7). Once weighed, the Brita water hydrated masses ranged from .490g to 1.059g with an average of .6756g (See Plant Weights page).
We decided to water the third set of plants with Gatorade to see if the nutrients helpful to humans would have the same effect on the marigold plants. In the first week of watering the plants with Gatorade none has sprouted (see figure 3). During the second week of the experiment all but one of the plants had sprouted and the average height of the plants was about half an inch with about 6 leaves. However, in the third week of watering with Gatorade, three of the previously sprouted plants had died and the other plants were about a week behind the Brita and tap watered plants in terms of growth (See Results Page). Beginning in the second week, the plants developed a sticky, moldy film across the top of the soil (see figure 4). By weeks 5 and 6 the soil of the plants had stopped absorbing the Gatorade given to them and the plants looked brownish and shriveled. Any remaining leaves were shrunken and a pale, sickly green. None of the Gatorade plants made it past an inch in height throughout the six weeks. When we uprooted the plants at the end and further observed the soil, there was moist, wet soil underneath the crust of moldy, sticky soil at the top (See figure 9). We also discovered that these plants had almost no root systems. The longest root wasn’t longer than two inches. Plants G2, 3, 4, 6, 9 were the only sprouts to have a very slim root system. Since Gatorade only had remnants of 5 original plants at the end of the experiment, there were only five plants to biomass. The plants were very small and incomparable to the other plants (see figure 8). The Gatorade masses ranged from .006g to .108g with an average of .0175g (See Plant Weights page).
After reviewing the data in order to determine which hydration method was most effective, we compared and contrasted the different statistics to find that the plants watered with Brita filtered water and tap water were successful while the Gatorade hydration method was not at all. In fact, after comparing numbers and using a t-test to compare biomasses between tap and Brita filtered, we believe that the Brita filtered water hydration was more effective than tap, what we originally thought would be the most successful. The Brita biomasses averaged .6756 g and B9 had the highest biomass of all the plants with 1.059g. The highest Gatorade biomass reached .108g which is completely incomparable to the tap water or the Brita hydration methods. So after reviewing the numbers, our hypothesis appears to be incorrect and Brita was the most successful. Our experiment in hydrating plants with Gatorade failed miserably and the effects that Gatorade has on a human being is not the same as the effect it has on plants. The sugar and salt content of the Gatorade was too concentrated and as plants don’t have a need for these nutrients, the plants didn’t receive the nutrients they needed to flourish. The ratio of sugar, salt and electrolytes in Gatorade is geared towards humans, not plants. We believe that possibly if the Gatorade solution was a little more diluted with water, the Gatorade hydrated plants might have had a better chance for survival. This theory may be explored more in further research or future investigation. As for why the Brita filtered water worked better than the tap hydration method, we think that the Brita filter may have removed many of the harsh chemicals and minerals found in tap water such as nickel and chlorine. Even though it wasn’t much of a significant difference between the two methods, the Brita had more initial sprouts and was further along in its growth at the end of the experiment. Both hydration methods had one flower bloom, but the Brita filtered method had many buds in addition to the blooms that were farther along than the Tap water method.
Our project was a smaller, modified version of many different experiments performed by scientists to understand the effects of different hydration methods on plant growth. By understanding the effects of different nutrients and ingredient ratios on the soil, gardeners and producers are better equipped to grow successful and healthy plants for the consumers. This information also might be found to be useful to manufacturers at Gatorade. This information could indicate if their product could ever be used for any other purpose. One question that we began to think about as the experiment progressed was what hydration method would actually be more successful than just regular water or Brita filtered water. The idea behind using the same replenishing method as Gatorade does for humans is an interesting concept and we began to wonder if there was a similar formula that would benefit plants.
In the future, if we decided to further investigate this issue of hydration methods and the effects of nutrient on plant growth, we might test out more products and expand the size and budget of the experiment. With greater resources, we could expand the degree to which we record data and possibly look into researching a “super-food” formula for plants. The lab group could have more variables to research, more sound ways of recording statistical and accurate data to help make more exact conclusions. In our experiment, having consistency between days and measurements was somewhat difficult as our resources were limited. With better tools and technology, our data and information could have been even more useful to other investigators and yield more interesting conclusions.
APPENDIX NOT INCLUDED ONLINE (SEE HARD COPY AND PICTURE DISK)
Beck, David E. “Fluids, Electrolytes, and Dehydration.” Ostomy Quarterly. 40 (Winter 2003): 66.
Bien, Linda. “Pick of the Plants; Know How to Select the Cream of the Crop.” The Post Standard. Final Edition (May 2005): E1.
Cardillo, Rob. “Hot Colors for Dry Times.” Organic Gardening. 50 (2003): 14.
Chaparzadeh, Nadar. "Antioxidative Responses of Calendula Officinalis Under Salinity Conditions." Plant Physiology and Biochemistry 42 (September 2004): 695-701.
Cox, Jeff. “The Magic of Marigolds.” Organic Gardening. 38 (1978): 68.
Hess, Kenneth Laferty. “Measuring Plant Growth.” Science Buddies. 2002.
http://sciencebuddies.org/mentoring/project_ideas/PlantBio_measuring_growth.shtml. 4 October 2005.
Jobbagy, Esteban G.; Jackson, Robert B. "The Uplift Of Soil Nutrients By Plants: Biogeochemical Consequences Across Scales." Ecology (September
“MiracleGro Potting Mix.” MiracleGro. 2002.
http://www.miraclegro.com/index.cfm/event/ProductGuide.product/documentType/product/category/%2FCategories%2FProducts%2FSoils%2FPotting+Soil+and+Amendments/documentId/9bc1eea5ad5baedbf4e90353fa98608f. 4 October 2005.
Munoz, Alejandro A. ""Bottomup Effects of Nutrient Availability on Flower Production."
Oecologia 143 (March 2005): 126-135.
North Carolina Department of Agriculture & Consumer Services. “Plant Nutrients.” 2005. North
Carolina Department of Agriculture & Consumer Services. 4 October 2005 http://www.agr.state.nc.us/cyber/kidswrld/plant/nutrient.htm#top.
Pramuk, Lee Ann. "Photosynthetic Daily Light Integral During the Seedling Stage Influences Subsequent Growth and Flowering of Celosa, Impatiens, Salvia, Targets, and Viola." HORTSCIENCE 40 (August 2005): 1336-1339.
Purchon, Nigel D. “Osmosis.” 23 February 2001. Gondar Design Biology. 4 October 2005
“Science of Hydration.” 2004. http://www.gatorade.com. 4 October 2005.
Smittle, Delilah. “Magnificent Marigolds.” Organic Gardening. 44 (1978): 54.
Stoll, Diana. “Dig Into Homework Before Buying Plants.” Home and Garden. (2005): 5.
Van Bodegom, Pete M. "Radial Oxygen Loss, a Plastic Property of Dune Slack Plant Species." Plant and Soil 271 (February 2005): 351-364.
Winterrowd, Wayne. “Marigolds.” Horticulture. 95 (1998): 50.
SAMPLE DATA SHEET
week plant height leaf count leaf size bud count flower count plant color thickness hydration notes
Week Monday Tuesday Wednesday Thursday Friday Saturday Sunday
10/25-10/31 pot plants and first watering mist plants water plants Take pictures of plants water plants
11/1-11/7 mist plants water plants mist plants water plants Take pictures of plants water plants
11/8-11/14 water plants water plants Take pictures of plants water plants
11/15-11/21 water plants water plants Take pictures of plants water plants
11/22-11/28 water plants thanksgiving thanksgiving thanksgiving thanksgiving pictures
11/28-12/5 water plants water plants Take pictures of plants water plants dry plants
12/6-1212/11 dry plants weigh plants finish report conclusions student generated lab report due
PLANT WEIGHTS DATA SHEET
2 .030 g
3 .018 g
4 .108 g
6 .013 g
9 .006 g
1 .609 g
2 .577 g
3 .820 g
4 .635 g
5 .490 g
6 .769 g
7 .525 g
8 .678 g
9 1.059 g
10 .594 g
1 .783 g
2 .652 g
3 .617 g
4 .582 g
5 .501 g
6 .854 g
7 .875 g
8 .381 g
9 .507 g
10 .627 g
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