APPLICATION OF PHYTOMONITORING FOR ESTIMATING THE WATER STRESS INDEX

Abstract

Cultivation of thermophilic vegetable crops in Siberian conditions is possible only if the limiting environmental factors of their habitat (heat and moisture availability) are brought to the optimum zone. This requires continuous phytomonitoring of habitat characteristics and plant status indicators performed by a phytomonitor with a set of sensors. Based on the results of phytomonitoring, the production process of the crops to be grown is managed in the real-time mode by conducting technological operations aimed at changing the limiting factor. A scheme has been developed for managing the production process of vegetable crops in canopies. To improve the heat supply, it is proposed to use protective screens with automatic control of inflow-and-exhaust ventilation. The basis is the automatic control scheme with feedbacks. Automatic ventilation control is carried out by measuring the air temperature inside the canopy and forming a signal to activate the mechanism drive. The water availability of plants is estimated by the value of the water stress index, calculated on the basis of measurements of air temperature and humidity and leaf temperature. An algorithm for calculating the water stress index has been developed and experiments have been conducted to measure the characteristics of the habitat and indicators of the state of plants in laboratory and field conditions. The characteristic of changes in the water stress index of plants inside and outside the canopy was obtained. Based on the value of the water stress index, it was concluded that the plants are adequately supplied with water. The results of the experiments showed high reliability of the phytomonitor and a set of sensors. Further studies will focus on improving the production process management system using phytomonitoring in real time based on the methodology of evapotranspiration calculation.