Competitive Interference of Silene nocturna in Durum Wheat Under Rainfed Mediterranean Farming Conditions

Abstract

Field investigations were conducted to evaluate the competitive interference of Silene nocturna on durum wheat (Triticum durum Desf.) under rainfed Mediterranean farming conditions, with emphasis on crop yield reduction, resource competition, and interference intensity across varying weed densities. Naturally infested and artificially supplemented plots were used to establish gradient weed populations, and crop growth parameters including plant height, tiller number, biomass accumulation, and grain yield were recorded throughout the growing season. Results indicated a significant decline in wheat performance with increasing S. nocturna density, with the most pronounced reductions observed during early-season competition when crop establishment coincided with peak weed emergence. Weed interference reduced aboveground biomass and grain yield primarily through competition for soil moisture and nutrients under limited rainfall conditions, characteristic of Mediterranean agroecosystems. Yield loss models revealed a strong negative exponential relationship between weed density and wheat productivity, indicating high sensitivity of durum wheat to early interference pressure. Phenological overlap between crop and weed further intensified competition, leading to reduced spike formation and lower thousand-grain weight under high infestation levels. Regression analysis confirmed that early emergence and prolonged coexistence of S. nocturna significantly amplified competitive effects compared to late-season infestations. The study highlights the critical importance of timely weed management interventions during the early growth stages of durum wheat to minimize irreversible yield losses. Integrated weed management strategies combining cultural, mechanical, and chemical approaches are recommended to mitigate interference impacts under rainfed conditions. These findings contribute to improved predictive understanding of crop–weed interactions in Mediterranean dryland agriculture and support development of sustainable wheat production systems under water-limited environments.