Germination Ecology and Seedbank Characteristics of Bifora testiculata in Winter Cereal Cropping Systems

Abstract

Weed persistence in winter cereal systems is strongly influenced by germination ecology and seedbank dynamics, particularly for species such as Bifora testiculata, which exhibits episodic emergence patterns. The present study investigates the germination behavior and seedbank characteristics of B. testiculata under controlled and field-simulated conditions relevant to winter cereal cropping systems. Germination responses were evaluated under varying temperature regimes, moisture levels, and light conditions, while seedbank density and vertical distribution were assessed through soil sampling across different depths and cropping histories. Results indicated that B. testiculata seeds exhibited strong dormancy mechanisms, with germination significantly enhanced under cool stratified conditions typical of winter seasons. Alternating temperature regimes promoted higher germination compared to constant temperatures, suggesting an adaptive response to seasonal cues. Moisture availability was a critical determinant of germination success, while light exposure had a secondary but significant stimulatory effect. Seedbank analysis revealed a predominantly surface-concentrated distribution, with higher seed densities in the upper soil layers of recently disturbed fields. In long-term cereal systems, seedbank depletion was slower, indicating persistence through recurrent replenishment and partial dormancy cycling. The study also observed that conventional tillage influenced vertical redistribution of seeds, whereas reduced tillage systems favored seed persistence near the soil surface. These findings highlight the ecological adaptability of B. testiculata and its ability to synchronize germination with favorable seasonal conditions in winter cereals.