CHLOROPHYLL FLUORESCENCE AS AN INDICATOR OF CROP GROWTH EFFICIENCY

Nicole Williams, BiochemistryMentor: Susan Moran,

Maria Pilar Cendrero MateoArizona Space Grant Consortium Symposium

Tucson, Arizona April 20-21, 2012

IntroductionPhotosynthesis efficiency (PE)

Can be used to measure crop health.

Knowing PE can better guide farmers in applying their resources to yield better profits.

X Difficult to directly measure

FLuorescence EXplorer

FLEX

Fluorescence

Hypotheses1. Fluorescence is negatively correlated with heat dissipation.

2. Fluorescence is an indicator of plant photosynthesis efficiency.

ExperimentCrops Alfalfa (CUF 101)

Treatment No stress conditions

Measurements

November 4th and November 6th 2011Fluorescence baseline measurement at 5 amFluorescence measurements from 7 am to 4 pm

Study site University of Arizona’s Campus Agricultural Center (CAC).

Mike Ottman

LICOR 6400

Measurements:- Photosynthesis efficiency- Fluorescence- Heat dissipation

Measurements

Data Analysis• Time was spent analyzing the data from each

leaf using graphs from the data collected by each leaf.

• At this point it became clear there were instances of cloud cover or similar circumstances that influenced our measurements.

Averages

Bad Data

Results

0

5

10

15

0 2 4 6 8 10Diurnal Measurement

Fluo

resc

ence

(a.u

.)

0

500

1000

1500

2000

0 2 4 6 8 10

Diurnal Measurement

PARi

(μm

ol m

-2s-1

)

0

0.5

1

1.5

2

0 2 4 6 8 10

Diurnal Measurement

Heat

Dis

sipa

tion

(a.u

.)

0

0.2

0.4

0.6

0.8

0 2 4 6 8 10Diurnal Measurement

Phot

osyn

. Effi

cien

cy

We found a negative relationship between fluorescence and heat

dissipation.

r2 pval

0.66 0.0260

2

4

6

8

10

0 0.5 1 1.5

Heat Dissipation (a.u.)

Fluo

resc

ence

(a.u

.)

Fluorescence and photosynthesis efficiency were strongly correlated.

r2 pval

0.88 0.00170

2

4

6

8

10

0.4 0.5 0.6 0.7

Photosynthesis Efficiency

Fluo

resc

ence

(a.u

.)

Concluding Remarks• Fluorescence can provide information to guide

farmers in their crop management.

• These findings support plans for use of the FLEX satellite to produce global maps of fluorescence.

• Future work: – Fluorescence sensitivity to

• Crop type• Plant stress• Environmental conditions

FLEX

FLuorescence EXplorer

Thank You!