Water consumption by Asteraceae weeds under field conditions

Abstract

Knowledge of weedy species' moisture demands is the basis for determining the relationships in relation to competition for water within agronomic plant communities, but it is also essential for assessing water balance in stands of cultivated plants. The aims of this work were to determine the flow of water in selected weed species from the Asteraceae family under field conditions and to verify the dependence of water flow on selected meteorological phenomena. Between 2006 and 2010, the water flow in Artemisia vulgaris, Conyza canadensis, and Lactuca serriola was studied under field conditions at a central European (Czech Republic) site. The sap flow rates (Q; kg per day) were measured by a sap flow meter. The growth stage, plant weight, and plant length at the end of the Q measurement periods were recorded. Adding the missing values of Q (kg h−1) was carried out by calculating Qcalc (kg h–1, calculated values), while Qfill (kg h–1, replaced values) was used for the final evaluation. In A. vulgaris, the average daily value of Qfill (kg per day) in individual years ranged from 0.020 to 0.148 (BBCH 67–75), while it ranged from 0.006 to 0.657 (BBCH 55–89) in C. canadensis, and from 0.002 to 0.327 (BBCH 59–85) in L. serriola. The experiments have demonstrated Q's dependence on global solar radiation and a vapor pressure deficit.