Influence of environmental factors on seed germination characteristics of invasive weed yellow starthistle (Centaurea solstitialis).
In order to response of yellow starthistle (Centaurea solstitialis) to environmental factors (temperature, drought and salinity), were conducted three separate experiments in 6 replicates in 2019 at Agricultural Sciences and Natural Resources University of Khuzestan. Temperature treatments included (5, 10, 15, 20, 25, 30, 35 and 40°C), drought stress (0, -0.2, -0.4, -0.6, -0.8, -1 and -1.2 MPa) and salinity stress (0, 50, 100, 150, 200, 250, 300 and 350 mM), respectively. The results of Temperature indicated that the highest germination percentage was at 25(94%), 20(93/33%) and 30°C (92%). The lowest germination percentage was at 35°C (22.66) and at 40°C germination completely was inhibited. Based on the estimation of the logistic equation three parameters (x50), germination percentage and germination rate were reduced by 50% at -0.70 and -0.46 -MPa levels of drought stress, respectively. The salinity required to reduce by 50% were in germination percentage (182.35 mM) and germination rate (130.57 mM). the knowledge of seed biology of yellow starthistle can help to manage emergence in the future.