Euphorbia davidii Subils, es una maleza anual que está presente en la zona centro de la provincia de Buenos Aires, Argentina. Se realizaron estudios para determinar el banco de semillas de esta especie y su distribución vertical en lotes agrícolas de Azul y Olavarría. Se extrajeron 240 muestras de suelo, provenientes de 60 puntos distribuidos al azar, a cuatro niveles de profundidad: 0-5 cm, 5-10 cm, 10-15 cm y 15-20 cm. Las extracciones se realizaron dos veces al año, en mayo y en septiembre. Las muestras fueron procesadas y las semillas separadas por tamizado en húmedo. Se evaluó germinación y viabilidad mediante la prueba de trifeniltetrazolio. Se cuantificaron 30.000 y 15.000 semillas m-2, para los lotes de Azul y Olavarría, respectivamente. En Olavarría, el 79% de las semillas se encontraron de 0-5 cm, de profundidad, el 14%, de 5-10 cm y el 7% restante de 10-20 cm. En Azul se observó una distribución vertical más homogénea. El 55 % de las semillas se encontraron de 0-5 cm de profundidad, un 24% de 5-10 cm, el 16% de 10-15 cm y el 5% en el muestreo más profundo. Las diferencias en la distribución se asociaron al manejo de los lotes. En ambas localidades la viabilidad de semillas, provenientes del estrato superficial, superó el 70%. Las semillas de estratos superficiales recolectadas en el lote de Olavarría, inmediatamente después de la dehiscencia, presentaron dormición, en cambio en las semillas provenientes del lote de Azul para el mismo momento de muestreo, no se observó dormición.

A crop–weed simulation model is presented to compare and evaluate integrated weed-management (IWM) strategies. Specifically, the model was parameterized for soybean crops in competition with Euphorbia davidii Subils. We used both weed and crop demographic data surveyed in agronomic fields of the central zone of the Buenos Aires province, Argentina, throughout two crop cycles (2011/2012 and 2013/2014). The proposed model underwent a calibration process and subsequent validation with a 70/30% data split, (N = 37). Two annual-based and one multiannual-based case studies were simulated to demonstrate the performance of the model. Different IWM strategies were compared under both operational and tactical planning horizons through the evaluation of different model outcomes (i.e., crop yield, interspecific competition, economic return, and environmental impact). Our results suggest that the inclusion of cultural management practices could reduce both weed interspecific competition by 46 to 97%, and weed seed production by 40 to 89 %. An increment in both expected crop yield, by 6 to 20%, and annual gross margin, by 44 to 199 USD.ha⁻¹, were obtained in silico for similar levels of environmental impact.

A crop-weed simulation model is presented to compare and evaluate Integrated Weed Management (IWM) strategies. Specifically, the model was parameterized for soybean crops in competition with Euphorbia davidii Subils. We used both, weed and crop demographic data surveyed in agronomic fields of the central zone of the Buenos Aires province, Argentina, throughout two crop cycles (2011/2012 and 2013/2014). The proposed model underwent a calibration process and subsequent validation with 70/30 % data split respectively (N=37). Two annual-based and one multiannual-based case studies were simulated to demonstrate the performance of the model. Different IWM strategies were compared under both, operational and tactical planning horizons through the evaluation of different model outcomes (i.e. crop yield, interspecific competition, economic return, and environmental impact). Our case studies results suggest that the inclusion of cultural management practices could reduce weed interspecific competition by 46 to 97 % and weed seed production by 40 to 89%. An increment in both expected crop yield, by 6 to 20%, and annual gross margin, by 44 to 199 US$.ha-1, were obtained in silico for similar levels of environmental impact.