Effects of Shade on Plant Growth, Development and Elements Content in Rosa damascene Mill.

Light is one of the main limiting factors, specialy in warm regions, for growth and development in plants and shade levels play an important role in the cultivation of medicinal plants. The aim of this research was to investigate the effects of shade levels (0%, 50%, 75%, and 100%) to find the best environmental option with maximum flowering in Rosa damascena. The plants were evaluated after eight mounths of treatments for morphological characteristics, macroelements contents, chlorophyll and carotenoids contents, peroxidase activity and flower numbers. The results showed that 0% shade induced stress on plant growth and reduced morphology parameters including plant height, fresh and dry weight; chlorophyll content; nitrogen content; soluble carbohydrates and flower numbers were decreased compared to those grown in shade levels. Root length, ion lekage, cartenoides content, potassium and phosphorus contents and peroxidase activity were highest in Rosa damascena under 0% shade after 8 months of growth cycle. Numbers of flower was greatest in Rosa damascena grown under 50% shade. In conclusion, Rosa damascena is a semi shade loving plant suitable to grow under 50% shading forhigh yield, in warm regions.