260 likes | 1.83k Views
The Effect of Detergent Concentration on Plant Growth. Erin Annunziato Ms. Pietrangelo. PJAS December 2010. Reason- Environment. laundry detergent in run-off fatal to plants human obstinacy more eco-friendly run-off. Hypothesis.
E N D
The Effect of Detergent Concentration on Plant Growth • Erin Annunziato • Ms. Pietrangelo PJAS December 2010
Reason- Environment • laundry detergent in run-off • fatal to plants • human obstinacy • more eco-friendly run-off
Hypothesis • If there is more than 5% laundry detergent in the water given to the plants, then the plants will not grow.
Types of Peas • Field Peas: • “split peas” • used in farming • Pisum arvense • Gardening Peas: • popular for home gardeners • sweeter and softer • Pisum sativum
Growing Pea Plants • Environment: • about 12-24º C (55-75º F) • moist soil • sunny or partially-sunny
Key Terms • photosynthesis: energy from the sunlight • water and carbon dioxide -> food and oxygen • detergent: cleans soiled surface (usually refers only to synthetic detergents) • soap- a kind of detergent (different chemical-makeup than synthetic detergents) • surfactants/surface active agents- consists of molecules that pull away dirt particles from surface • ANOVA- an analysis of variance
Lab Details • Independent Variable: concentration of detergent in the waterLevels: 1% detergent, 2% detergent, 3% detergent, 4%detergent, 5% detergent, 6% detergent, and 7% detergentTrials: 3Control: 0% detergentDependent Variable: Growth of plants (cm)Constants: type of plant, total amount of detergent/water added,, watering times and frequency, growing environment and time
Materials • Pisum sativum seeds • Tide Laundry Detergent • water • potting soil • 8 pots- 11 centimeter circumference; 9.5 centimeter height • graduated cylinder • ruler • 7 plastic bottles
Procedure • Plant 5 pea seeds 2 centimeters deep per 8 pots, each pot filled 6.3 centimeters with potting soil • Water the pots with pure water (0% detergent) every day until stems are at adequate heights to begin experiment • Measure test levels 1-7% detergent by mixing water and detergent in 500 mL water plastic bottles: • 1%: 5 mL of laundry detergent and 495 mL of water • 2%: 10 mL of laundry detergent and 490 mL of water • 3%: 15 mL of detergent and 485 mL of water • 4%: 20 mL of detergent and 480 mL of water • 5%: 25 mL of detergent and 475 mL of water • 6%: 30 mL of detergent and 475 mL of water • 7%: 35 mL of detergent and 470 mL of water • Water plants each pot with the same amount (100 mL) of corresponding concentration level every day. • Record the plant height in centimeters every third day.
Average Plant Heights (cm) Results Heights (cm) Measurement Day * These values have been gathered with only two trials, rather than three
Average Growth (cm) Difference in Heights (cm) Results Measurement Day
Addressing 6% • height of plant 1 decreased • cells may have shrunk • unlikely measurement error because there is a trend • plant 1 was the tallest • plant 3 increased, then decreased • plant 2 did not change then died
Null hypothesis: There are no differences in the observed heights between the treatment groups ANOVA: Results Source of Sum of d.f. Mean F Variation Squares Squares between 202.8 7 28.97 1.742 error 266.2 16 16.64 total 469.0 23 The probability of this result, assuming the null hypothesis, is 0.169 The null hypothesis is not rejected: There was no significant difference of the heights between the different groups that were treated with different concentrations of detergent
Conclusions • Hypothesis: • If there is more than 5% laundry detergent in the water given to the plants, then the plants will not grow. • I cannot support nor refute my hypothesis • 1-5% died, while 6% survived • not enough data • control survived
Sources of Error • inadequate sunlight • different starting maturity • small pots • human error • graduated cylinder
Improvements • more mature plants • growing lamps • same plant height • lower laundry detergent concentrations • larger growing space • regulate root depth
Extensions • root depth • soap • different plants
Thank you :) • Ms. Pietrangelo • My mother and my au pair