Responses of arching and traditional training systems to shading in cut rose (Rosa hybrida cv. Avalanche)

Nowadays، various training systems are utilized to grow greenhouse roses. Some of the training systems permit high canopy light penetration and hence increase canopy photosynthesis rate. The aim of this investigation was to evaluate the response of arching and traditional training systems to shading (0 (no shading/control)، 25، 50 and 65%) and their effects on marketing quality of cut roses (Rosa hybrid. cv. ‘Avalanche’)، in the greenhouse condition. The experiment was carried out as split plots، based on completely randomized blocks design، with four replications and two plants assigned to each experimental unit. Results showed that training systems affected some qualitative traits. Plants trained with arching method produced longer flowering stems with higher fresh and dry weight and also higher leaf area over decapitated shoots. In both training systems، no significant difference was observed in time of sprouting، flower shoot diameter and specific leaf area. Increased shading significantly reduced shoot diameter and shoot fresh and dry weight; while it increased specific leaf area. However، shading had no significant effect on shoot length and leaf area. Based on the results of this experiment، application of arching training method could lead to improvement in qualitative properties of cut roses compared to traditional method under low light intensity and/or shade stress.