Climate effect on <i>Avena fatua</i> field emergence dynamics: A 38‐year experiment in the semiarid Pampean region of Argentina

Climate events modulate weed population dynamics mainly by influencing field seedling emergence patterns. Field experiments aiming to study the influence of climate on early-stage establishment weeds are utmost importance from a practical and strategic decision-making management point view. The objective this was analyse effect variations Avena fatua in southwest area semiarid Pampean region Argentina. patterns A. were monitored 1977 2015. Seedling counts destructively sampled at weekly intervals. Three quadrats (1 m2 each) randomly distributed 5 ha experimental with high natural density absence crop. Results show that strategy species is highly plastic striking variation response year-to-year signals. strategies classified as staggered, early, medium late based both chronological hydrothermal-time parameters. In short-term, precipitation regimes during after-ripening phases largely explained resulting strategy. long-term, combined reduction frequency mean minimum temperature correlated an increase staggered pattern. also out adaptability under study, further suggesting bet-hedging fitness could diminish risk decline changing scenarios. From agronomic perspective, occurrence extended window would complicate definition optimal time for control. Thus, tailoring decisions Southern Oscillation Index (SOI) episodes (neutral, negative or positive) forecast plus implementation models lead more accurate sustainable decisions.