Useful Image-Based Techniques for Manual and Automatic Counting Using ImageJ for Horticultural Research

Strawberry plants in the field, shown in ImageJ.

Counts (e.g., number of leaves, fruits, seeds, or plants) are a common type of data gathered in horticultural research. In many instances, using ImageJ can increase the ease and accuracy of gathering count data. When image processing can easily separate objects of interest from the background, automatic counting with ImageJ can eliminate tedious manual counting processes. Furthermore, additional plant growth data, such as leaf area, plant width, and canopy area, can be collected from the same image. The image processing and analysis techniques introduced in this article are easily accessible and simple to use and thus can be adopted not only by researchers, but also by Extension agents and students. This new 10-page publication of the UF/IFAS Horticultural Sciences Department is part of a series introducing various image-based measurements with ImageJ for horticultural research. Written by Lillian Pride and Shinsuke Agehara.

A Simple, Inexpensive, and Portable Image-Based Technique for Nondestructive Leaf Area Measurements

Cropped photo of a leaf in the ImageJ program prior to processing.

This new 6-page article, part of a series introducing various image-based measurements for horticultural research, introduces a simple, inexpensive, and portable image-based technique for nondestructive leaf area measurements. It uses an imaging apparatus made with ordinary office supplies to obtain leaf images in greenhouse or field environments. Leaf images are then processed and analyzed to measure leaf area using ImageJ, an open-source image processing program. Because both image capture and analysis are performed nondestructively, leaf area can be measured on the same leaf repeatedly, enabling the monitoring of leaf growth over time, as well as photosynthesis and transpiration. This technique is particularly useful to researchers and students studying leaf growth and physiology in greenhouse or field environments. Written by Shinsuke Agehara, Lillian Pride, Mariel Gallardo, and Jose Hernandez-Monterroza, and published by the UF/IFAS Horticultural Sciences Department.