How does varying amounts of Plant food effect the rate of photosynthesis By: Austen Rubenstein Delaney Rubenstein Lars Scheibel Samantha Fox

Background Information  Independent Variable: Concentration of Plant Food (Osmucote)  We chose Osmucote plant because that’s what Mrs. Coury had lying around and we thought it good to use an established brand.

Background Information  Osmocote is an all-purpose plant food for indoor or outdoor plants.  It is used to transplant plants as well as mix and make your own potting soil.  It is a slow release plant food which helps to avoid chemical burn.

Background Information  Photosynthesis is the conversion of light energy to chemical energy.  It occurs in green plants, algae, and bacteria.  The chemical formula for photosynthesis is 6CO 2 +6H 2 O in the presence of sunlight to yield C 6 H 12 O 6 +6O 2.  Photosynthesis is divided into two sets reactions: light-dependent reactions and light-independent reactions.  Light reactions rely on colored molecules to capture the energy of light (photon). NADPH and ATP participate in the dark reactions.

Purpose  Do different concentrations of Osmocote plant food affect the rate of photosynthesis in bean plants?

Hypothesis  If more Osmocote plant food than the recommended amount is added to the bean plants, then the result will be an increase in the rate of photosynthesis until the bean plants can no longer efficiently utilize any more nutrients at which point the rate of photosynthesis will level out.

Basic Procedure  Plant 16 bean plants in four cups  Place plants in the greenhouse  Water the plants equally each day of class until soil is damp  Transfer plants to the light boxes  Add plant food to the cups to begin treatments  Record plant height  Perform floating leaf disk assay test  Record results in a table and perform statistical tests

Basic Procedure CupCup 1Cup 2Cup 3Cup 4 Amount of Osmocote Plant Food Recommended amount Control(no plant food) More than recommended amount Less than recommended amount

Basic Procedure Recommended = 82.4 Plant Food Balls Over = Plant Food Balls Under = 41.2 Plant food Balls

Data

Data (Recommended) t-Test: Two-Sample Assuming Unequal Variances (Control and Recommended Amount) Variable 1Variable 2 Mean40 Variance Observations12 Hypothesized Mean Difference0 df11 t Stat P(T<=t) one-tail t Critical one-tail P(T<=t) two-tail t Critical two-tail Confidence Value is

Data (Over) t-Test: Two-Sample Assuming Unequal Variances(control and Over the Recommended) Variable 1Variable 2 Mean Variance Observations12 Hypothesized Mean Difference0 df18 t Stat P(T<=t) one-tail t Critical one-tail P(T<=t) two-tail t Critical two-tail

Data (Under) t-Test: Two-Sample Assuming Unequal Variances(Control and Under Recommended) Variable 1Variable 2 Mean40 Variance Observations12 Hypothesized Mean Difference0 df11 t Stat P(T<=t) one-tail t Critical one-tail P(T<=t) two-tail t Critical two-tail Confidence value is

Limitations and Implications  Osmocote will keep a plant full for four months so more test time would have been useful in gathering data.  The lamp we used was smaller in size so all cups did not fit under the light evenly.

Limitations and Implications  Varying Vacuum treatments could cause the results from the FLDA (Floating Leaf Disk Assay) to be skewed -Too much vacuum treatment kills cells -Not enough vacuum treatment, causes the leafs not to sink

Conclusion  Plant containing over the recommended amount had a rate of photosynthesis greater than that of the other trials.

Works Cited