Seed Dormancy and Germination Biology of Bifora radians as a Weed in Winter Cereal Cropping Systems

Abstract

Seed dormancy and germination ecology of Bifora radians were investigated to understand its persistence and emergence behavior as a problematic weed in winter cereal cropping systems. Laboratory and field experiments were conducted to evaluate the effects of temperature, moisture, light conditions, and burial depth on seed dormancy release and germination potential. Freshly collected seeds exhibited strong primary dormancy, which gradually decreased under favorable stratification conditions, indicating a requirement for after-ripening and environmental cues for germination. Germination was significantly influenced by temperature regimes, with higher germination percentages observed under cool conditions typical of winter cropping seasons. Alternating temperature cycles further enhanced germination, suggesting sensitivity to diurnal fluctuations. Light exposure promoted germination in surface-sown seeds, while deeper burial reduced emergence due to limited light penetration and altered temperature dynamics. Seed burial depth experiments revealed highest emergence from shallow soil layers, whereas deeper seeds remained dormant but viable, contributing to long-term seedbank persistence. Moisture availability played a critical role in breaking dormancy and supporting radicle emergence, with drought conditions strongly inhibiting germination. Seasonal field observations showed peak emergence during autumn and early winter following rainfall events, aligning with crop establishment periods. The species demonstrated a persistent seedbank strategy, enabling survival under repeated tillage and cropping disturbances. These adaptive germination traits contribute to its successful establishment and competitiveness in winter cereal systems. Understanding the dormancy mechanisms and germination requirements of B. radians is essential for predicting emergence patterns and optimizing timing of weed management interventions.