Evaluating plant stress conditions in paprika by comparing internal electrical conductivity, photosynthetic response, and sap flow

Abstract

A non-destructive analytical method to measure plant internal electrical conductivity (ECp) was developed to monitor plant responses to changes in environmental conditions. However, the relationship between ECp and plant physiological responses has not yet been established. The objective of the study was to evaluate the relationships among ECp, photosynthetic responses, and sap flow in paprika to monitor ECp in relation to changes in environmental conditions. High ECp levels were related to high photosynthetic rate, stomatal conductance, and transpiration rate. Sap flow in the plant was also associated with ECp with a correlation coefficient of 0.606. However, the sap flow reflected only water flux, while ECp was determined by both water and ion content in stems of paprika. The ECp was predicted using environmental factors including temperature, irradiation, and relative humidity. A comparison of measured and predicted EC(p)s could be used to detect unusual cultivation conditions for paprika such as drought and high temperature. Plant responses to water shortage were reflected by lower ECp compared to the predicted value.