S05 - Session P2 - Colored shading nets affect growth and ornamental quality of potted roses in a south Mediterranean climate

Authors: Youssef Rouphael *, Giancarlo Fascella, Simona Aprile

Roses are among the most used ornamental plants throughout the globe. Outdoor nursery production of potted roses is strictly related to the local environmental conditions in particular in south Mediterranean areas, characterized by warm and dry summers with high solar radiation. Actually, in these districts shading nets are largely used to reduce solar radiation during summer, thus to diminish light stress for plants as well as leaf and flower discoloration and, consequently, to increase plant aesthetic effect. The purpose of our study was to assess the effect of colored shading nets on growth, ornamental quality and eco-physiology of potted roses grown under Sicilian climate. Three different shading nets (black, white and green) with the same reduction of solar radiation (50%) were used on two rose species ( Rosa canina and R. corymbifera ) grown in open air in plastic containers filled with a peat/perlite (3:1, v/v) mixture. Plant growth and quality were significantly affected both by colored shading nets and by rose species as higher plant height, number of leaves, leaf area and leaf greenness were recorded on R. canina under green shading net. No difference was observed as regards fresh and dry biomass production and partitioning of the two studied species. Leaf gas exchanges were influenced by shading nets as higher photosynthetic rate and transpiration were measured in R. corymbifera leaves under green shading net. Results from the present study may give useful information to rose growers of south Mediterranean regions in order to improve plant growing conditions and, therefore, ornamental traits and marketable value of potted roses.