The impact of within-row spacing on the productivity of glasshouse roses grown in two planting systems

• Published in: The journal of horticultural science & biotechnology Vol. 74; no. 6; pp. 721 - 728
• Main Authors: Mosher, J. M., Turner, D. W.
• Format: Journal Article
• Language: English
• Published: Taylor & Francis 1999
• ISSN: 1462-0316; 2380-4084
• DOI: 10.1080/14620316.1999.11511179

Stem yield and quality of roses for cut flower production were evaluated. The plants were grown in two planting systems as an alternative to the traditional ``vase-shaped'' system. In the trellised system, two cultivars of Rosa hybrida (cvs Gabrielle and Kardinal) were planted in a commercial glasshouse in 3.m sections of bed. Within-row spacing was varied to give 6-16 plants m -2 . After a three-month establishment phase the basal shoots were bent to an angle of 308 above horizontal and restrained with a trellis wire. Flowering shoots sprouting from axillary buds along a basal shoot were harvested at their lowest node, minimizing branching. Compared with ``vase-shaped'' rose plants at the same density, trellised roses produced 24% more basal shoots, 46% more flowering shoots (cv. Gabrielle) and approximately 46% less blind shoots per plant over five months. Phenotypic variation was greater in cv. Gabrielle than in cv. Kardinal in response to within-row spacing, as indicated by the number of basal shoots formed. Within-row spacing, over the range explored, did not affect the number of flowering shoots per basal shoot. Trellising rose plants increased stem yield and quality, but production over the long-term requires further investigation. The single shoot planting system contained a mixed population of single-stemmed rose plants of Rosa hybrida (cvs Gabrielle and Gerdo). It was grown in a field over a range of within-row spacings to give 20-105 plants m -2 . Over three harvests, increasing the number of plants by 10 plants m -2 reduced the proportion of flowering shoots by 4.4%. Expressed on a unit area basis, a five-fold increase in plants m -2 produced a three-fold increase in stem production.