Sampling of Prunus laurocerasus trees

Samplings were carried out weekly between April and October in 2015 and 2016. On each sampling date, leaves were taken from different parts of the tree canopy, i.e. lower, middle and upper. The number of sampled trees per site was determined according to the total number of the trees in each orchard (Table 1). Approximately 20 leaves per tree were collected. The samples were put into paper bags placed inside plastic bags, labeled, and transferred to the laboratory.