S09 - Session P3 - Challenges and innovations in sustainable production at level of farming techniques and production systems - Particles and microbes on urban grown plant

Authors: Beatrix Waechter Alsanius *, Most Tahera Naznin, Emina Mulaosmanovic

Growing crops in urban area are of paramount importance for sustainable cities. However, air quality in urban settings is often impaired due to natural and anthropogenic pollutants such as dust, sands, industries and traffic. This affects the settlement of unwanted agents on leaf surfaces that may serve as food. We studied the impact of site and crop in three urban sites in Sweden, namely at a densely trafficked road site with and without shelter through a hedge, and a low traffic urban garden site in down town Malmoe. A rural site with very low traffic situated on the SLU campus in Alnarp served as a control. The study was performed as a two-factorial study including four sites and three crops grown for five weeks during summer and autumn in 2018 and 2019. Model crops were chosen based on plant habitus and leaf characteristics, with focus on leaf area and density of trichoma. Preliminary results indicate that the number of viable bacteria on leaves was driven by crop and leaf area, whereas the occurrence of coarse particles was dependent on site and weather conditions. No interactions between viable bacterial counts and coarse or fine particles were found. The presence of a hedge played an important role for the settlement of coarse particles on model crop leaves.