Assessment of Four-Seasonal Quality and Yield of Cut Flower Roses Grafted onto Rosa Rootstocks

Cut roses are ornamental crops that are produced year-round, and the quality and yield of these cut flowers vary depending on the temperature and light intensity of the four seasons. Grafting improves productivity by increasing adaptability to negative environments, such as high temperature and low light intensity. The effectiveness of grafting depends on the type of the scion and rootstock. In order to confirm the effectiveness of stenting on roses, two varieties of cut roses ( Rosa hybrida cv. Pink Beauty and Pink Shine) were grafted onto three rootstocks ( R. multiflora Natal Briar, R. indica Major, and Rosa multiflora Hort. No. 1), which are widely used in cut rose, and the quality and yield of the cut flowers were investigated year-round according to the four seasons; then, principal component analysis (PCA) was performed. The Rosa hybrida cv. Pink Beauty (PB) used as the scion showed high yield and excellent growth in autumn when the light intensity was high and the temperature was low. The PB grafted onto the R. multiflora Natal Briar (NA) rootstock showed improved growth in spring, autumn and winter, excluding summer, and had the effect of lengthening the stem. The growth of PB grafted onto R. indica Major (RI) rootstock was also improved in spring, autumn, and winter, except summer, and in particular, the stem was lengthened and thickened. The rosa hybrida cv. Pink Shine (PS) was a variety whose yield of cut flowers increased in summer when the temperature was high. The PS grafted onto the three rootstocks gave a higher yield of cut flowers than the PS scion. The graft of PS/Natal Briar gave longer stems than the PS scion, and the graft of PS/Major gave thicker stems than the PS scion. PS grafted onto the Rosa multiflora Hort. No. 1 (N1) rootstock gave more petals than the PS scion. As such, cut roses grafted onto the Rosa canina cv. Natal brier (NA) improved the stem length, increasing the adaptability to relatively high temperatures, and the Rosa indica cv. Major (RI) improved the stem length and stem diameter, enhancing the adaptability to relatively low temperatures.