Germination Response of Avena sterilis to Soil Depth, Temperature Fluctuation, and Pre-Chilling Treatments

Abstract

Wild oat (Avena sterilis) is a highly competitive weed species that exhibits strong dormancy mechanisms, enabling persistence in diverse agroecosystems. The present study investigates the germination response of A. sterilis seeds under varying soil depths, temperature fluctuation regimes, and pre-chilling treatments to understand dormancy release and emergence behavior. Seeds were subjected to controlled burial depths, alternating and constant temperature conditions, and cold stratification periods prior to germination assays. Results indicated that soil depth significantly influenced emergence, with maximum germination observed at shallow burial depths, while deeper placement resulted in reduced emergence due to limited light penetration and altered oxygen availability. Temperature fluctuation treatments promoted higher germination compared to constant temperatures, suggesting that diurnal thermal variation acts as a key environmental cue for dormancy break. Pre-chilling treatments significantly enhanced germination percentage and reduced mean germination time, indicating effective dormancy alleviation through cold stratification. Interaction effects revealed that optimal germination occurred when pre-chilling was combined with alternating temperature regimes at shallow soil depths, whereas deeper burial suppressed seedling emergence regardless of temperature treatment. These findings demonstrate that A. sterilis possesses a flexible dormancy strategy regulated by environmental signals, enabling synchronized germination under favorable field conditions. The species’ ability to respond to temperature fluctuations and chilling exposure contributes to its successful establishment in temperate cropping systems. Overall, the study highlights the ecological adaptability of A. sterilis and underscores the importance of integrating knowledge of dormancy ecology into weed management strategies. Targeting seed bank dynamics through timely tillage and optimized sowing practices may help reduce emergence and improve long-term weed control in cereal-based agroecosystems.