Peony Research 2009

Abstract

Research has been conducted since 2001 to assist growers in identifying components of peony field cut flower production and distribution from field selection and planting to post harvest handling and packaging for export. This experiment addressed three components of the production cycle: field planting dates, root quality and plant productivity, and post harvest handling of cut stems. In a comparison of planting times (autumn, spring or as containerized plants in mid summer), ‘Sarah Bernhardt’ and ‘Felix Crouse’ showed no difference in shoot number and growth one full year after planting. ‘Duchess de Nemours’ and ‘Alexander Fleming’ showed significant reductions in growth compared to the other cultivars, and we suspect disease rather than planting time as the problem. All treatments where bud break had occurred in storage with ‘Duchess de Nemours’ and ‘Alexander Fleming,’ new shoots rotted, and recovery was slow. A treatment of elemental sulfur was not sufficient to protect roots from storage rot. ‘Sarah Bernhardt’ roots and crown buds were weighed, counted and measured prior to planting in order to learn if a correlation exists between root quality and subsequent growth and flowering. Three root attributes were correlated with the total number of stems produced: total number of eyes per plant, total number of roots per plant, and root fresh weight. Characteristics such as root length and maximum diameter were not correlated with subsequent growth. We found no relationship between any root characteristics and the number of flowering stems and foliage height in the first year. The attributes that showed correlation could not be fitted to a linear or curvilinear model explaining the nature of the correlation. Larger sample sizes will be necessary to clarify these relationships. The best method for handling peony cut flowers for greatest vase life is to cut peonies dry and store them dry in a cooler (34°F) at 80+% relative humidity until shipping. Use of water in buckets in the field or pulsing flowers with water in the cooler does not improve vase life of peonies. Under optimum conditions, ‘Sarah Bernhardt’ peonies lasted up to 15 days in a vase, 8-9 days from bud break to full bloom, and an additional 5-6 days in full bloom. Chilling in a cooler is the most important attribute to long vase life.