Native and not‐native weeds in globe artichoke fields under diverse cropping systems in Sardinia (Italy)

Globally, both native and non‐native weeds pose an important economic threat to crop production in agricultural areas asthey compete forspace, light, water and nutrientsfrom the soil. The rate between native and non‐native weeds in agricultural cropping systems has only been scarcely studied as the weed flora is more frequently considered as a single unit. However, pathways of introduction and spread and impacts might be diverse. Agricultural areas can be sites of introduction of new alien species, therefore it needs to be periodically monitored or they could act as reservoirs of alien species that can also invade adjacent semi‐natural to natural areas, thus specific management plans are to be put in place. This study was conducted in the framework of a project funded by the Sardinian Regional Authority (i.e. “CarBio – Carciofo Biologico: innovazione e sostenibilità di filiera”). The objective of the study was to assess the native and non‐native weed flora in Sardinian globe artichoke fields, under different management types (conventional or alternative) along a temporal and geographic gradient. To estimate weed cover in the field, we established a network of 1 × 1 m control plots between the artichoke’s rows which were GPS located, and this resulted in a total of 12 plots per field. The presence/absence and cover degree of all weeds were evaluated. The investigated fields are located in three main macro‐areas of the island of Sardinia (Italy) in which globe artichoke cultivation represents the most important and economically relevant open field horticultural crop. We also evaluated weed flora diversity as a result of weed management changes in globe artichoke cropping systems. Specifically, we evaluated the following three management systems: (i) conventional cultivation, (ii) improved monoculture in which in globe artichoke cropping system was introduced no synthetic fertilizer supply and a short cycle of French bean (Phaseolus vulgaris 'Bronco', both for additional income and for N supply, and (iii) organic systems characterized by no synthetic fertilizer supply and an inter‐row crop cover of pea (Pisum sativum ‘Attika’). Taking into account Cynara growth cycle, floristic data were collected during three different periods of the year and species were monitored from late winter when inflorescence developed (BBCH code 50‐9) to summer when globe artichoke was BBCH code 30‐9 (leaf development) during the first growing season (2018–2019). As a preliminary result, we present the full checklist of the recorded weed species and the seasonal differences of the coverage of native and non‐native weeds. Oxalis pes‐caprae is one of the most abundant alien species in the globe artichoke fields during the late winter – early spring season, despite the many attempts to control its spread. The research is in its initial phase, however, the data collected so far have highlighted significant differences among cropping systems which suggests the possibility of identifying optimal and sustainable strategies for the management of native and non‐ native weeds in Cynara fields, by developing more eco‐friendly production systems.