Influence of photoselective netting on growth of cherry laurel (Prunus laurocerasus l.) saplings

Cherry laurel (Prunus laurocerasus L.) is an ornamental shrub used mainly for hedges. It is tolerant of pruning and air pollution, making this species ideal for urban horticulture. Cherry laurel is propagated commercially by stem cuttings, which are rooted in the period from June to April. Nets have long been used in horticulture against hail, wind and excessive sunlight. Recently, a new technology of photoselective nets has appeared. They are not only used for plant protection, but also stimulate the desired physiological plant responses by spectral manipulation and improve light utilization by scattering. This study was conducted in 2019 and 2020 in the nursery garden of the Faculty of Forestry and Wood Technology, Zagreb, Croatia. Rooted cherry laurel cuttings from a heated greenhouse were transplanted into outdoor beds on June 28, 2019, at 10 x 20 cm spacing in rows with a north-south orientation. Three photoselective nets were used: a white, yellow, and red net (AGRITECH S. r. l., Eboli, Italy) and a standard green shade net as control. In each treatment, 30 rooted cuttings plus grafts were transplanted, for a total of 120 cuttings. The following morphological variables of the seedlings were measured: Height, root collar diameter, root collar cross-sectional area (TCSA), slenderness coefficient, number of first-stage branches in the lower third of the plant, total number of first-stage branches, total length of first-stage branches in the lower third of the plant, total length of all first-stage branches, and average length of first-stage branches in the middle part of the plant. The measurement was performed on June 9, 2021. Data were statistically analyzed using SAS Ver. 9.4 statistical software (SAS Institute, NC) using ANOVA and Tukey's HSD test (P ≤ 0.05). The main objective of this study was to investigate the possible effects of different colored photoselective nets on the vegetative characteristics of cherry laurel. The results show that there are no statistically significant differences in all the above vegetative traits of cherry laurel seedlings grown under different types of nets. Therefore, green shade netting can be used for cherry laurel seedlings in nurseries. Further studies are needed to test this technology under other agroecological conditions