2 Does Caffeine affect how fast a plant will grow? If I have 3 of the same plants, and I water one with caffeinated coffee, one with water, and one with decaffeinated coffee, which one will grow the fastest?
3 Interesting factsCaffeine is found in many plant species where it acts as a natural pesticide.Caffeine is a stimulant drugCaffeine is found in many plants, beans, leaves, and some fruits.Humans have been using caffeine since the Stone Age.In humans caffeine is a central nervous system that temporarily wards off drowsiness and restores alertness.Caffeine is the worlds most widely consumed psychoactive substanceOne of the worlds primary sources of caffeine is the coffee beanTea is another common source of caffeineOver the years people have been putting caffeine into things like soap and shampooToo much caffeine can kill you
4 HypothesisIf I water a plant with caffeinated coffee, then it will grow faster than a plant watered with decaffeinated coffee, and one watered with water, because I think that the caffeine will increase the rate at which the plant grows.
5 Materials 3 plants of equal size and type Folgers caffeinated coffee Folgers decaffeinated coffeeWaterCoffee makerPitcherSunlightRulerPaperComputer/flash driveLog book
6 Procedure 1) purchase 3 plants of the same type and height 2) label the plants3) place all 3 plants in sunlight4) measure with a ruler the beginning height of each plant in my log book5) record the beginning height of each plant in a log book6) brew one pot of Folgers caffeinated coffee7) brew one pot of Folgers decaffeinated coffee8) fill a pitcher with water9) water plant #1 with the caffeinated coffee (every 2-3 days)10) water plant #2 with decaffeinated coffee (every 2-3 days)11) water plant #3 with water (every 2-3 days)12)Measure each plants growth after every watering13) record each plants growth in the log book14) determine which plant has grown the most15) check my hypothesis to see if it was correct
7 Control Variables The same type of plant Same amount of sunlight Same amount of liquids per plantEach plant got watered every 2-3 daysSame brand of coffee
8 Observations The Plant watered with regular water grew the fastest The Plant watered with caffeinated coffee grew the second fastestThe plant watered with decaffeinated coffee grew the slowestAlthough the amount of caffeine given to each plant was different, all three plants had the same color of leaves and soilAlthough all three plants started out at the same height, they all grew at different rates
9 Data Plant Number Type of Water Beginning Plant Height 10/30/09 Ending Plant Height12/03/09Plant GrowthPlant 1Caffeinated9 4/16 inch.10 0/16 inch.12/16 inch.Plant 2Decaffeinated9 13/16 inch.9/16 inch.Plant 3Plain water10 6/16 inch.1 2/16 inch.
10 Data AnalysisBy observing my experiment I noticed that the plant watered with plain water grew the most, the plant watered with caffeinated coffee grew the second most, and the plant watered with decaffeinated coffee grew the least. There was a significant amount of growth differential between the plant watered with plain water, and the plant watered with decaffeinated coffee.
11 ConclusionMy hypothesis was that the plant watered with the caffeinated coffee would grow the fastest. This was incorrect. It was in fact the plant watered with the plain water that grew the fastest, and the plant watered with the caffeinated coffee grew second fastest, and the plant watered with the decaffeinated coffee grew the slowest.I would probably pick a different type of plant for experiment next time because the plants I picked did not grow very fast. This made it harder to tell if the reason why one grew faster than the others was because of the caffeine or not.One new question that I have is, are there other reasons why the plants grew at different rates besides caffeine or no caffeine? Also, are there chemicals in both the caffeinated and decaffeinated coffee that could have slowed down the plants growth compared to the one that was watered only with the plain water? In addition to my other questions I also wondered if there were any errors that I could have made that may have altered the results of my experiment.
12 References The Naked Scientists Forum MyCaffeineAddiction.com Wikipedia EncyclopediaPlantingScience.org