Earth-Kind® rose trialing: An international model for the identification of regionally-adapted landscape roses

Landscape roses are exceedingly popular worldwide and have become the flagship flowering shrub trialed within the Earth-Kind® Environmental Landscape Management System (started at Texas A&M University to support environmental stewardship). Multi-year, replicated Earth-Kind regional rose trials are conducted under low-input conditions throughout a geographical region. Cultivars with superior regional performance are designated as regional Earth-Kind roses providing consumers and all sectors of the horticulture industry confidence that they can be successful with these cultivars given basic plant care. Earth-Kind Rose Trials are now underway in multiple U.S. regions as well as in Romania. Current trial parameters include: a randomized complete block design with 2.4 m plant spacing, incorporating 7.6-10.2 cm of compost preplant and maintaining 7.6-10.2 cm of organic mulch throughout the trials for nutrition, planting own-root plants (to avoid graft incompatibilities), irrigating regularly during the first year of establishment then greatly reducing or eliminating irrigation later, and no pruning, pesticides (unless in extreme circumstances that would otherwise jeopardize the trials) or traditional fertilizers. Minor modifications are allowed based on regional needs (e.g. closer spacing and pruning allowed to remove dead wood in colder regions). Plants are evaluated monthly during the growing season beginning in year two through the end of the 3- or 4-year study using a 10-point horticultural scale (includes pest tolerance and aesthetic factors) as well as overall flower number and coverage. The strong experimental design allows for the potential for performance data to be published in peer-reviewed scientific literature. The trials also support further studies surveying plants for additional, regionally-important traits. Laboratory screens, such as surveying for black spot resistance to known races, are conducted to help complement the field trial data. Earth-Kind rose trialing provides a consistent and strong international rose trialing and outreach model to identify and promote genetically-superior cultivars for the benefit of regional consumers, nursery professionals, landscapers, researchers, and breeders.