If you are measuring a plant in a pot, the ruler should begin at ground level.
The equation for the growth rate formula is (S2−S1)T{\displaystyle {\frac {(S2-S1)}{T}}}where S1=first measurement, S2=second measurement, and T equals the number of days between each. [3] X Research source This is an extremely general figure. Plant growth rate is extremely fluid and can be subject to major variations day by day. Currently, there is no way to accurately predict exact daily growth rate without the use of sophisticated laboratory equipment.
Repeat this process to find the width of the leaves. Measure the leaves at their widest part. Be as specific as possible; get the measurement down to centimeters and millimeters if you can.
You can calculate the leaf number growth rate. This modification of the growth rate formula will tell you how many leaves are approximately growing per day. The equation for this growth rate is (L2−L1)T{\displaystyle {\frac {(L2-L1)}{T}}}where L1=first leaf count, L2=second leaf count, and T equals the number of days between each. The leaf size formula is the same as the plant height formula. Instead of height, the variable is the surface area. The equation for the growth rate formula is (S2−S1)T{\displaystyle {\frac {(S2-S1)}{T}}}where S1=first surface area measurement, S2=second surface area measurement, and T equals the number of days between each. [4] X Research source
In the future, you can use this template to measure leaves with greater ease. Hold up the leaf at the bottom of the paper with it centered around the smallest circle. Mark the largest circle it fills without going over and record that as the leaf size.
If you do not have a drying oven, a food dehydrator set at the same temperature will also work. A conventional oven with a convection setting may work as well. Set it at 140 Fahrenheit for six hours. It will dry out the plants well enough, although a little moisture may remain. Do not leave a conventional oven on overnight.
If leaves fall off during cooling, keep them. Place the detached leaves on the scale with the rest of the plant.
The equation for this growth rate is (W2−W1)T{\displaystyle {\frac {(W2-W1)}{T}}}where W1=first dry weight, S2=second dry weight, and T equals the number of days between each.
