Time trends of field vegetable yields and yield gaps in northern latitudes using a Bayesian approach

Open-field production of horticultural crops has high economic value in Finland. Profitable production requires sufficiently high yields and good product quality. This study’s objective was to assess the temporal and regional variation in the yield of three field vegetables (carrot, onion, and white cabbage) in Finland. Second, our aim was to quantify the yield gap of these species in their main production regions. The analysis was based on comprehensive statistical data (2012–2021) modelled using a Bayesian approach. Time trends varied between plant species and regions. In carrot, the yield tended to remain similar. In onion, some statistically significant increasing regional time trends were found, whereas in white cabbage the significant time trends were mostly negative, indicating a decreasing yield. The yield gap was largest in onion, but its economic value was highest in carrot. To ensure profitable and sustainable production, it is necessary to reduce the yield variation and yield gaps. More efforts are needed to adapt to climate change and control production risks.