David Zlesak, associate professor of horticulture at UW-River Falls gave two presentations at the Sixth International Symposium on Rose Research and Cultivation held Aug. 25-30, in Hannover, Germany.
The first presentation centered on the Earth-Kind model for rose trials, which are conducted under low-input conditions throughout a geographical region to identify cultivars with superior performance for that region.
The Earth-Kind model combines the best of traditional horticulture with organic gardening, with the goal of having low maintenance landscapes. Zlesak has early Earth-Kind observational plantings of roses on the UWRF campus. The presentation was co-authored by faculty at other universities across the U.S. engaged in the Earth-Kind Environmental Management System.
Zlesak’s second presentation focused on rose black spot disease and efforts to identify new genetic markers linked to a gene that confers resistance to the disease. Zlesak collaborated with colleagues at the University of Minnesota on this research.
The symposium is held under the auspices of the International Society for Horticultural Science (ISHS) every four years. It covers all areas of rose research and cultivation practices with updates on the most recent developments in the field. As in the previous symposia, the scientific presentations were combined with a mid-symposium professional tour.
The tour included visits to the two largest German rose breeders, Kordes’ Söhne in Sparrieshoop and Rosen Tantau in Uetersen. Kordes is the preeminent breeder in disease resistant landscape roses; Tantau focuses more heavily on cut roses. A third tour stop was to the German variety protection office involved in rose performance documentation of new varieties relative to established varieties in order to secure intellectual property rights throughout Europe. Attendees also toured the Europa-Rosarium Sangerhausen. With 8,300 rose cultivars, it is the biggest rose collection in the world.