Phenological Stages of Development of Tribulus terrestris L. (Zygophyllaceae R. Br.) Under the Conditions of the Thracian Lowland Floristic Region of Bulgaria

Abstract

The phenological stages of Tribulus terrestris L. in the Thracian Lowland floristic region of Bulgaria were studied. Growth characteristics of the species, the length of the vegetation period and the duration of each phenological stage were studied in three consecutive years. A detailed phonological spectrum was presented. A direct relation was established between the duration of the phenological stages, the calendar periods and the climatic features of the respective year