Application Interval and Concentration Affect Nursery Crop Response to Cyclanilide

Abstract

Abstract Cyclanilide (CYC) is a bioregulator that promotes the development of lateral shoots in ornamental and fruit tree crops, potentially reducing the need for mechanical pruning during nursery production. In 2006, three foliar applications of 200 ppm CYC applied at a 1, 2, or 3 week application interval increased shoot counts of ‘Diana’ sasanqua camellia, ‘Sky Pencil’ holly, and ‘Snow White’ Indian hawthorn when compared to pruned and unpruned controls. However, application interval had no effect on shoots counts in holly or camellia and minimal effect in Indian hawthorn. Foliar injury to Indian hawthorn was severe, regardless of application interval. In 2007, three applications of 50 or 100 ppm CYC were applied at a 1, 3, or 6 week interval to ‘Sky Pencil’ holly and ‘Snow White’ Indian hawthorn. At 120 to 150 days after initial treatment (DAIT), shoot counts in both species increased with application interval, and all CYC-treated plants formed more new shoots than controls. Transitory injury to new growth of Indian hawthorn, although not quantified, appeared to increase as application interval decreased. At 120 DAIT foliar injury was no longer evident in Indian hawthorn. At 180 DAIT quality rating of both cultivars increased with CYC application interval and was greater than that of controls, and CYC-treated plants were visibly more dense and compact.