4 proven methods of how to measure leaf area
You have a plant leaf and need to know how to measure leaf area. What is the most efficient way to do this calculation? And how about accuracy? Let’s consider these questions and find the most relevant solution for you.
How to measure leaf area with millimetre graph paper?
There are a couple of methods for measuring leaf area destructively— starting from old-fashioned and finishing with digital and innovative. The difference between them are in the accuracy, time consumption, easiness to work and, surely, price.
Let’s start with the simplest methods, available for anyone.
Millimetre Graph Paper and Squared Paper
If you are doing your first leaf area measurements ever, you can try the simplest method. Take a squared paper like a sheet of paper from your notebook. Find a pen or pencil. That’s it! Your first leaf area measuring kit is ready.
The same situation you’ll have, when choosing millimetre graph paper.
In fact, millimetre graph paper is a special kind of paper. Basically, it has one line per millimetre and centimetre index lines on letter-sized paper.
How to measure leaf area with graph paper?
- Place a leaf on top of the paper sheet.
- Fix leaf on the same position with your fingers or using double-sided cello tape.
- Outline a leaf using a pen or a pencil
- Count of millimetre squares
A quick hint: do not try to memorize your count, write it down.
However, this method is extremely clear and easy, there is one huge disadvantage. The results are not completely accurate. Plus, measuring leaf area with graph paper requires long hours. Particularly, if you are lucky to have more than one leaf to measure.
Leaf area with ImageJ and other solutions
PC software (ImageJ, Adobe Photoshop, WinFOLIA, etc.). To make leaf area measurement, you need to have a photo or scan of a plant leaf and further processing is based on work with leaf digital image. In most cases, this method provides quite precise results but you need to become a guru of using this software. Every application has specific options and conditions in order to measure the leaf surface area. Leaf Area Scanners — handhold, portable (LI-Cor, CID, WinDIAS). Good stuff for non-destructive methods of leaf area measurement. You need to take a leaf area scanner with you and go to the field. This equipment provides accurate results and is comfortable to use. But they are too expensive for an ordinary farmer or scientist. Also, they have a problem of saving data: you cannot synchronize your leaf area measurement with data cloud or your PC.
Mobile applications know how to measure leaf
Mobile apps. There are two known Android-based mobile apps to measure leaf area: Petiole and Easy Leaf Area. Both of them are free to download, have an affordable price and provide precise plant leaf data. The way how they work is almost intuitive: open app, calibrate the camera, place a leaf in front of a camera and press the button on the screen. The app shows leaf area measurement in square centimetres. However, Petiole goes a little bit further and provides more options for work. If you have more than one leaf area measurement, this app will show you average leaf area and also there is an option to make an experimental comparison of different leaves.
Instead of a conclusion, it would be good to highlight that you can reach your agriculture goal and measure leaf area with any of these methods.