Development of a Mobile Platform for Wheat Phenotyping

Plant phenotyping refers to monitoring traits or physical characteristics of plants. Crop scientists / breeders are interested to find relations between phenotypes and genotypes, which improves yields. Manual measurement currently is the primary method for phenotyping, which has several limitations, and requires intensive labor. Designing an affordable High-throughput Phenotyping Platform (HTPP) for monitoring wheat features in different stages of their growth can provide valuable information for crop-breeders to study correlation between genotypes and phenotypes. Conducting automatic field measurements can improve crop productions. In this paper, we discuss development of a mechatronic system, which is a wheeled mobile platform for HTPP of wheat. The system can measure traits such as, canopies height, temperature, vegetation indices, and is able to take high quality photos of the crop. The system includes software for data and image acquisition. The main contribution of this study is autonomous, reliable, and fast data collection, for wheat and similar crops.

It has been predicted that humanity will need more demand for food and resources in the future. More than 820 million people in the world were suffering hunger in 2018, which is mostly rising in African sub regions, Latin America and Western Asia. Also, there is a prediction that humanity will need double demand for food and resources by 2050. To improve agricultural industry, crop breeding should be closely influenced by genetic analysis of plants. Analyzing genetic features of a plant is a necessary practice in agriculture related research to make an interaction between crop-breeders and experts who use phenotyping to gather features of plants. However, phenotyping needs to be more advanced to provide more information. Measuring characteristics, such as plants height, temperature, greenness, and having high quality picture for image processing are challenging and time consuming. Our focus is on phenotyping of wheat, which is a valuable commodity for Canada, and using ground based mobile platform.

The importance of plant phenotyping has been discussed and clarified for improving agriculture industry and support future agricultural production in several reported literature. Phenoscope is a HTPP (High-throughput Phenotyping Platform) for indoor. This platform is equipped with a zenithal imaging system and makes watering automatically. A high-throughput non-destructive plant phenotyping platform, which has light curtain and spectral reflectance sensor is proposed in another paper. Biomass determination can be compared, and the combination impact of the calibration data sets can be measured. Phenobot 1.0 is another ground-based platform that is designed for tall and densely planted crop species. This field-based platform is auto-steered and self-propelled and is equipped with RGB (Red-Green-Blue) cameras that are positioned horizontally and vertically. This structure of the cameras provides 3D feature of the plants to measure plants height and stems diameter. Another platform is Pheno Trac 4, which is equipped by ultrasonic sensors and  infrared thermometers and is able to measure height and temperature of the plots. Other information such as biomass, tissue chlorophyll contents and water status can be drawn by use of hyperspectral sensor’s data.

Recently, we developed an affordable field based HTPP for monitoring wheat plants. This platform has several sensors, which are ultrasonic, infrared thermometer, and Crop Circle sensors used for measuring height, temperature and vegetation indices of the plants. In addition, this platform is equipped with RGB webcams that can capture images from each plot. Using the RTK-GPS antenna, these images and data are geo-tagged into the plot level.