Jul 19, 2018
Assessing Canopy Structure of Soybean Plants
- 1UIUC
Protocol Citation: Isla Causon, Stephanie Cullum 2018. Assessing Canopy Structure of Soybean Plants . protocols.io https://dx.doi.org/10.17504/protocols.io.rmsd46e
License: This is an open access protocol distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Protocol status: Working
We use this protocol and it's working
Created: July 12, 2018
Last Modified: July 19, 2018
Protocol Integer ID: 13714
Find the Line number
Find the Line number
Use a map of the field to find the line number. Each line of Soybean has 4 rows. There are always 5 lines of Soybean next to each other. Between these 5 lines are 'buffers' which contian two rows of generic Soybean (for protective reasons). The lines follow a weaving pattern of accendnig numbers, so the next Soybean line will always be next to the previous one.
Chose the 2nd and 3rd row
Chose the 2nd and 3rd row
Sample leaves form the 2nd and 3rd row (the middle ones). This allows the outer rows (1st and 4th) to act as buffers and minise the variation within the line
Choose 3 plants
Choose 3 plants
Choose 3 plants that are representative of the whole line (not too small or too big). Use these plants to take measurements on.
An example of the height variation can be seen below.
Write down measurements
Write down measurements
Use the sheet below to write down measurements (or an equivilant sheet/spreadsheet).
Assess the plant
Assess the plant
Assess each plant in turn. Taking all measurements before moving on to the next plant.
Take a measurement of the overall plant height (cm)
Take a measurement of the overall plant height (cm)
Measure for where the stem reaches the soil (bottom), to the bottom of the top most flower bud (top).
Measure the height of the internodes (cm)
Measure the height of the internodes (cm)
For each internode, take a measurement (in cm) of the height of each internode. For the first internode, take a measurement from the ground to the beginning of the internode. Then measure from there to the bottom of another. Continue this until you reach the bottom of the top flower bud.
Measure the length of the secondary stems (cm)
Measure the length of the secondary stems (cm)
At each internode, see if there are any secondary stems (stems which come off the main stem). If there are, measure (in cm) the length of the stem (from the main stem to the base of the end leaf).
Measure the angle of the secondary stem
Measure the angle of the secondary stem
Use the protractor to measure the angle of the secondary stem to the vertical position (90 degrees form the ground). There is a grading system. The grade of 2 or 1 is an acute angle (less than 90 degress), the grade of -2 or -1 is an obtuse angle (more than 90 degrees), in between is the grade 0. If the angle is inbetween two grades (dotted lines), 0.5 can be used.
Count the number of tertiary stems
Count the number of tertiary stems
For each secondary stem, count the number of tertiary stems (also called petioles) that come off of the secondary stem.
Repeat up the plant
Repeat up the plant
Repeat these measurements up the plant, internode by internode, until the top of the plant is reached.
Measure the length and width of leaves (cm)
Measure the length and width of leaves (cm)
For each plant, divide the height of the plant by 3. Each third represents a different level of the canopy. There is the bottom third (lower canopy), the middle third (middle canopy), and the top third (upper canopy). In each level of the canopy, measure the length and width (cm) of 4 representative leaves. You will end up with 2 measurements for 12 leaves for each plant. Note that here may be leaves in the middle canopy layer, while their secondary stems attach to the stem in the lower canopy level - count these leaves as middle canopy.
Please note, these images show incorrect use of the ruler.
