Introduction

Leaf Area Measurement is a hard task for researchers with hundreds or thousands leaves to calculate leaf area. In this case study, we used different methods to measure leaf area of trees. We needed to compare the leaves of trees in big cities and in their natural conditions.

Brief About the Scientific Area

Trees in big cities are adopted for the surrounded conditions more than the same species of wood put down their roots in the natural conditions. In other words, we are speaking again about the influence of salt-affected soil, metal heavy, gases, etc.

We define the level of development for a tree by the degree of its organs’ development, particularly leaves. We researched differences between the natural territory, for example, parks, green areas – the leaves were larger and contain less heavy metals there. Instead, leaves grown in the streets were not so.

Leaf Area Measurement With Different Methods

PC-based method

We measured the leaf area index. For this task, we scanned leaves and put images into PC software. This program calculates shaded pixels. Then we transferred pixels to the area and the overall process took a lot of time. We did not know about ImageJ at that moment.

By the way, we used the unlicensed program. It seemed that it worked, brought some results but we cannot prove them and think that these results were accurate. This method was the simplest.

Scientific Methods

Other methods where scientific-based, for example, “carving” method, when we were doing die-cutting of leaves but again it was not precision. Taking the leaf and die-cutting from the other leaf, the measurements are not the same.

Correlation index is also discussed in the scientific literature but not works perfectly for our tasks.

Handy Method

Grid count method using millimetre graph paper bring the same results. Human error is presented: one person has seen a small square but another person has not seen. Measurements of leaf area are influenced by a human factor too much.

In other words, individual leaf surface measurement was very time-consuming and exhaustive work.

Digital Method of Leaf Area Measurement

We had six variations with three replicates. In fact, one breed of the tree gave 2,400 leaves. We had 5 – 6 tree breeds. So we had to take 2,400 leaves from each breed and measure leaf area of all leaves.

We spent 2 – 3 days for one variation. We have done only sampling and have not measured leaf area of all 2400 leaves but calculated the average measurement.

But with Petiole we measure the area of 10 – 15 leaves in a minute.

Conclusion About Leaf Area Measurement

Based on the scientific results of applying mobile application Petiole, we believe that it is a good tool for individual leaf area measurement. It helps to save efforts and time. Also, it increases the number of leaves, which we measured. Nice tool for our plant laboratory.