Real-Time Assessment of Mandarin Crop Water Stress Index

Area of Science:

• Agricultural Engineering
• Remote Sensing
• Plant Physiology

Background:

• Conventional methods for detecting crop water stress are often laborious and time-consuming.
• Non-contact, non-destructive sensing offers continuous and automated monitoring capabilities.
• Infrared thermography presents a promising approach for real-time plant stress assessment.

Purpose of the Study:

• To evaluate the Workswell WIRIS Agro R infrared camera (WWARIC) for monitoring water stress in mandarin plants.
• To assess the camera's efficiency and speed in detecting water stress levels.
• To determine the viability of using WWARIC for optimizing irrigation scheduling.

Main Methods:

• A randomized complete block design with varying soil moisture levels (50-100% FC) was employed.
• Infrared imaging captured canopy temperature, alongside air temperature and vapor pressure deficit measurements.
• Crop Water Stress Index (CWSI) was calculated using Idso's approach and baseline equations, with WWARIC data correlated against relative leaf water content (RLWC).

Main Results:

• A high correlation (R² = 0.75) was found between WWARIC-derived CWSI (CWSIW) and Idso's CWSI (CWSI(Idso)).
• The WWARIC successfully identified water stress from 12m altitude using empirical, differential, and theoretical modes.
• The camera's real-time color map feature enabled immediate stress level determination without complex analysis.

Conclusions:

• The WWARIC is a precise, swift, and user-friendly tool for real-time detection of mandarin water stress.
• This technology significantly aids in scheduling irrigation, improving water management in agriculture.
• The study validates the practical application of infrared thermography for precision irrigation.