Abstract
Roses are classified as neutral day plants, but high light and cool temperatures produce high quality flowers in roses. As light quantity, the light quality and its special spectra can affect the flower yield and quality. This research aimed to study of the effect of LED light (control (sunlight), blue and red spectra's) and nano-chelated potassium at three levels (0, 1.5 and 3 g/l) on some morphophysiological and biochemical traits of Rosa hybrida cv. Dolce Vita. Light and nano-chelated potassium treatments have a significant effect on most traits measured in the present study. According to the results, the use of red light and nano-chelated potassium in rose cultivation improved the quality characteristics and increased vase life. The highest fresh and dry weight of flowering branch and plant height was observed in red light treatment and the concentration of 3 g/l nano-chelated potassium. Biochemical parameters such as phenolic compounds, leaf and petal flavonoids, petal anthocyanin content, antioxidant capacity and vase life were also significantly increased under red light and with the concentration of 3 g/l nano-chelated potassium compared to the control. In general, it can be said that the use of red light and a concentration of 3 g/l nano-chelated potassium, can be effective in improving the quality of rose flowers, especially in low light condition.