Abstract: In this experiment we observed and later identified the effects of certain herbicide application on plant growth. We planted a total of fourteen seeds in each of our eight different pots; seven soybean seeds and seven corn seeds. We designated four different treatment groups that were labeled the following; control, unknown, known, and extra treatment group. Over the course of two weeks the plants were placed in a greenhouse and given the proper measures to germinate. Then, the greenhouse staff administered an herbicide to our known group and an herbicide to our unknown group. Additionally, our group administered the extra treatment, Diet Coke, to our extra treatment group. We then made careful observations of each plant and concluded that our known herbicide was indeed Round Up, which resulted in the death of our soybean plants. After observing our unknown group, we hypothesized that the herbicide used was 2-4, D, which resulted in leaf and root decay of our soybean plants. Lastly, we concluded that the Diet Coke treatment resulted in steady growth of our plants, because of the added carbon, oxygen, and hydrogen that the pop provided for our plants.

Introduction:

The purpose of this experiment was to observe and later identify the effects of certain herbicide application on plant growth. In order to understand the following aspects and steps of the experiment, it is crucial that the basics of plant growth are discussed. Also, it is important to identify the plants used in the experiment.

For nearly 3 billion years life remained in constant development in the water, however it was when Plantae evolved that life on earth was forever changed. The first plants evolved about 470 million years ago, tracing back to a lineage of multicellular green algae. It was the migration of algae from water to land that kick started the colonizing of land-dwelling organisms. Plants can be classified as multicellular autotrophs that use chloroplasts in order to photosynthesize. The process of photosynthesis occurs in the leaves, utilizing sunlight as the initiator for the formation of sugars from carbon dioxide and water molecules, and results in the release of oxygen gas into the air. Today, there is a wide range of diversity in the plant kingdom (Singh-Cudy 55).

About 365 million years ago gymnosperms evolved, which later became the first plants to evolve the seed, which consists of the plant embryo and an encased supply of stored food. During the early stages of growth the seedling relies on the food storage as it’s main source of nutrients until it is large enough for its own leaves to begin making food through photosynthesis. The seedling’s roots burry down into the soil in order to anchor the new plant into its new source of water and minerals from the soil (Singh-Cudy 61). As soon as the seed begins to germinate we can identify if a plant is a monocot or a dicot. A monocot has only one seed leaf, which is usually long and thin, whereas a dicot has two seed leafs (“Monocots verses Dicots Explained”). For the purposes of this experiment we need to identify soybeans as dicots and corn as monocots.

Our experiment began by planting a total of fourteen seeds in each of our eight pots; seven soybean seeds and seven corn seeds. We separated our eight pots into four groups consisting of an unknown, known, control, and extra treatment group. Over the course of two weeks our plants were placed in a greenhouse where they were given time and the proper resources to germinate and begin growth. Our plants were then treated accordingly to the label that they were given in the beginning of our experiment. In our experiment our plant growth was manipulated using a known and unknown herbicide, as well as an extra treatment. After the plants were allowed two weeks of growth the greenhouse staff administered two different herbicides accordingly followed by our group’s administration of the extra treatment. It was then our responsibility to make observations of our plants and work to discover the identity of our unknown herbicide.

The known herbicide applied was Glyphosate, otherwise commercially referred to as Round Up. Round Up acts on the plant by prohibiting protein synthesis of tyrosine, phenylalanine, and tryptophan. The herbicide affects strictly dicotyledons. We hypothesized that if our known plants were indeed treated with the herbicide Round Up, then our treated soybean plants would die (“Agricultural Herbicides”). We predicted that the leaves of the treated soybean plants would show signs of browning and wilting, as well as death in the roots of the plants.

After making careful observations of our unknown group of treated plants we identified the herbicide used to be 2, 4-D commonly used to treat broad-leafed plants. 2, 4-D is a synthetic plant hormone that is absorbed through the leaves and then transported to the tissues of the plant. The herbicide leads to plant death, more selectively in the death of monocotyledons, by causing cells in the water and nutrient rich carrying tissues of the plant to divide and grow without stopping. We hypothesized that if our unknown plants were treated with 2,4-D, then our soybean plants would die. We predicted that the leaves of our soybean plants treated with 2, 4-D would decay and have shortened, decayed root lengths, while our corn plants may show minor signs of leaf decay (“2,4-D”).

Lastly, we observed the effects of our extra treatment, Diet Coke, on our corn and soybean plants. Diet Coke is a sugar-free soft drink that is sweetened with an artificial sweetener known as aspartame. This keeps the contents of the drink absent of sugar. Diet Coke consists mostly of carbonated water, which results from pure water into which carbon dioxide gas has been dissolved under pressure. Because plant growth requires components such as carbon, oxygen, and hydrogen, we predicted an increase in the overall growth of both plants (“Gardening Know How”).