System for indicating water stress in crops which inhibits data collection if solar insolation exceeds a range from an initial measured value

摘要

An apparatus and method for indicating whether irrigation of an agricultural crop is required based on the measurement of crop water stress. The apparatus and method include a plurality of sensors for sensing a plurality of conditions related to the agricultural area, including crop canopy and air temperatures, and relative humidity, from which the water stress condition of the crop can be determined, and for generating signals representative of each of the sensed parameters; an electronic device connected to the sensors receiving the sensor signals for determining therefrom the water stress condition of the crop; and an output device connected to the electronic device for visually displaying the calculated water stress index. The apparatus may be embodied in a portable unit that provides immediate analysis of environmental and crop data along with the crop water stress index. To ensure that measurements are taken under generally similar light conditions, an initial solar insolation value is compared to a value measured during each subsequent data collection. The canopy temperature measurement is rejected if insolation is not within a range of the initial value, thereby inhibiting calculation of the crop water stress index.