Seedling Emergence Pattern and Cohort Dynamics of Papaver hybridum in Winter Cereal Fields of Mediterranean Regions

Abstract

Seedling emergence patterns and cohort dynamics of Papaver hybridum were investigated in winter cereal fields across Mediterranean agroecosystems to understand its temporal recruitment behavior and persistence in arable systems. Field experiments and observational surveys were conducted over multiple growing seasons to quantify emergence timing, cohort structure, and environmental drivers influencing population establishment. Results indicated that seedling emergence of P. hybridum occurred in distinct cohorts primarily during autumn and early winter, coinciding with the onset of rainfall and declining soil temperatures. A smaller secondary flush of emergence was recorded in early spring, influenced by intermittent rainfall events and soil moisture availability. Emergence intensity was strongly regulated by surface soil conditions, with shallowly positioned seeds contributing predominantly to early cohorts. Seedling establishment was highest under moderate temperature regimes and adequate soil moisture, while drought conditions significantly suppressed emergence. Cohort dynamics revealed that early-emerging cohorts had higher survival and reproductive success due to reduced crop competition during early cereal establishment stages, whereas later cohorts experienced strong suppression under closed crop canopies. Winter cereal density and canopy development played a critical role in regulating seedling survival, with higher crop density reducing light availability and limiting weed establishment. The species exhibited a bet-hedging emergence strategy, enabling long-term persistence through staggered recruitment across the season. Environmental variability, particularly rainfall distribution and temperature fluctuations, significantly influenced cohort size and timing. The findings highlight the adaptive emergence behavior of P. hybridum in Mediterranean cereal systems and its ability to synchronize recruitment with favorable environmental windows.