Image based Crop Monitoring Technologies in Protected Horticulture: A Review

TL;DR

This review discusses image-based crop monitoring technologies in protected horticulture, highlighting current systems, camera technologies, and future challenges in monitoring taller crops in semi-controlled environments.

Contribution

It provides a comprehensive overview of existing crop phenotyping platforms and explores future research directions for commercial-scale protected crop monitoring.

Findings

Various camera technologies are used for plant trait extraction.

Current systems mainly focus on small or short plants.

Future challenges include monitoring taller crops in semi-controlled environments.

Abstract

Future food security is a major concern of the 21st century with the growing global population and climate changes. In addressing these challenges, protected cropping ensures food production year-round and increases crop production per land area by controlling environment conditions. Maintaining the growth and health of crops in these facilities is essential to ensure optimum food production. However, this is a laborious work and is currently done manually. Image-based non-destructive plant phenotyping is an emerging research area that reduces the skilled labour cost while enhancing the monitoring of crop growth, health, and identifying phenotype-genotype relations for plant breeding. With the proliferations of protected infrastructures and targeted plants, different technologies and sensor setups are needed for image-based crop monitoring. Conveyor-type plant-to-sensor systems, bench-top or gantry-based systems are commonly found in research facilities focussing on phenotyping of small, relatively short, or movable model plants. This review examines the literature on crop monitoring and phenotyping platforms in both field and protected facilities and explains different camera technologies and their ability to extract different plant traits. The review highlights the future research directions of image-based monitoring of commercial scale protected crops where crops can be relatively tall or vertically supported under semi controlled environments, which presents new challenges and is rarely covered in the literature.