Assessment of maize water status using a consumer-grade camera and thermal imagery

Abstract

The analysis of plant response to water deficits can help us to identify appropriate water-saving and irrigation methods. The goal of this study is to assess the potential of eight indices derived from a modified consumer-grade camera and a thermal camera for monitoring the relative water content (RWC) of maize. The study design was a randomized complete block design with three replications and 16 treatments with four levels of irrigation water percentage based on field capacity (100% Fc, 80% Fc, 60% Fc and 40% Fc), and four levels of nitrogen (without nitrogen, 100 kg N/ha, 200 kg N/ha and 300 kg N/ha) were used. RWC values were used to evaluate the performance of the eight crop water stress indicators. The results showed that the best performance results of the studied vegetation indices were DANS, CTSD and CTCV, respectively. As observed, R2 values were 0.88, 0.76 and 0.67, respectively. HIGHLIGHTS Low-cost modified camera and thermal camera was used to collect images of maize plants.; The performance of Tc-based indicators and vegetation indices for monitoring maize water status was assessed.; High correlations were found between indices based on thermal images with maize water status.; RGRI-Otsu method was used to improve the accuracy of Tc extraction and background elimination.;

Keywords

• maize
• modified camera
• otsu algorithm
• red-green ratio index
• relative water content