Weed species changes over long-term period in sugar beet production.
Sugar beet is spring crop planted in rows of 45 or 50 cm distance that provides a large surface area for weeds to germinate and grow. Nowadays, as a part of IPM, weed control measures in sugar beet production needs to be oriented to sustainable use of herbicides. Since the change of management practice affect the weed biodiversity, it need to be better understood. For that purpose, a comparison of the actual weed community (2017) in sugar beet fields of north-eastern Croatia with a similar floristic surveys were carried 2002 and 1977. Changes in species richness, floristic composition and structure occurred in the last 40 years and were estimated using community-based indices and multivariate ordination techniques. The average weed species number per relevé and average weed cover declined significantly through time. Many of archeophytes, frequently surveyed in the past, decreased significantly in their cover in recent surveys. However, the most radical changes in the weed community structure were observed in invasion of Abutilon theophrasti, Ambrosia artemisiifolia and Datura stramonium during last two decades. The results also suggest that intensification of the land use over the investigated period affects weed community in sugar beet and led to decrease in weed species diversity.