Indirect Measurement of Plant Height in Cotton (Gossypium hirsutum)

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Indirect Measurement of Plant Height in Cotton
(Gossypium hirsutum)

• Pam TurnerOklahoma State University

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MassaSonic Ultrasonic Sensor

• M-5000/95
• Conical Beam Angle 8o
• Min. Distance 1 ft
• Max. Distance 13 ft
• Output units 20 mAmps
• Operating temp. -20o C to 65o C

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Methods
Sonar Measurement

• Measure and record height from ground to face of
  sensor
• Place sensor over plant. It must be 4 40
  inches from the plant.
• Record reading provided by sensor (mAmps). Fifty
  readings are taken at each growth stage.
• Convert mAmps to inches.
• 3.7809 x Voltage Reading -3.1698
• 5) Value subtracted from sensor height to give
  plant height.

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Methods
Hand Measurement

1. Measure and record the distance between plant and
   face of sensor.
2. Using Microsoft Office Excel, subtract height of
   sensor from hand measured height to get plant
   height.

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Sensor Height 47.25 in. (120 cm) from
ground View Diameter 6.59 cm
Growth Stage 17 Leaf
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Sensor Height 41.5 in. (105.4 cm) from
ground View Diameter 5.79 cm
Growth Stage Square Growth Midpoint
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Sensor Height 43 in. (109.2 cm) from
ground View Diameter 5.99 cm
Growth Stage White Bloom
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Sensor Height 43 in. (109.2 cm) from
ground View Diameter 5.99 cm
Growth Stage Flowering 5-7 Days
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Sensor Height 42.5 in. (107.9 cm) from
ground View Diameter 5.92 cm
Growth Stage Developing Boll
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Sensor Height 55 in. (139.7 cm) from
ground View Diameter 7.67 cm
Growth Stage Developing Boll
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Cotton Sonar Height
y 0.96x 4.39 R2 0.95
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Plant Development 2006
Developing Boll
Square Growth Midpoint
17 Leaf
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Conclusions

• Where OSU cotton research is going
• Establish relationship between measuring plants
  by hand and measuring plants with ultrasonic
  sensor
• Develop a benchmark setting for cotton to look at
  plant or target biomass NDVI
• Establish a method for yield prediction