Impact of level and timing of pruning on flower yield and secondary metabolites profile of Rosa damascena under western Himalayan region

Pruning has been implicated as a promoter of bud outgrowth or shoot branching and flower yield in Rosa damascena Mill., but the extent and time of pruning are tightly regulated by the climatic conditions of the growing region. In western Himalaya region in India, the effect of extent and time of pruning on flower yield and secondary metabolites of R. damascena is still unsolved. Thus, a field experiment comprising three levels of pruning and four different time of pruning was conducted to confirm that the higher yield and quality can be achieved through the standardization of pruning practices. Principal component analysis showed that pruning at 90 cm height from ground level (FGL) on 15th December is preferable for higher flower yield and essential oil. The yield data suggest that moderate pruning (90 cm FGL) leads to an increased rate of flower production (11.33 and 13.22 g new shoot(-1)). Pruning on 15th December produced 10.6-42.77% higher flower yield compared with pruning on 31st October. The quality of oil is considerably affected by level and time of pruning. The results have suggested that the higher yield and quality of R. damascena can be achieved through the standardization of pruning practices. (C) 2013 Elsevier B.V. All rights reserved.