Shortening the Production Cycle of Clematis

Abstract

Clematis (Clematis ×hybrida) is among the flowering plants well-recognized by the retail consumer; however, production has not traditionally fit into standard greenhouse production systems. One reason is the relatively long 2-year production cycle from propagation to flowering. Four experiments were conducted with clematis ‘H.F. Young’ to understand the factors that influence shoot development and flowering of clematis so that strategies could be developed for bulking, providing a cold treatment, and flowering the plants with a shortened production time. The first experiment showed an increase in shoot and flower numbers and a decrease in time to flower as the duration of cold treatment increased from 0 to 9 weeks and the photoperiod increased from 9 to 16 hours. The second experiment resulted in greater shoot and flower numbers when plants were forced at 21 °C as compared with 27 °C. The third experiment showed that the application of ethephon (500 or 1000 mg·L−1) during bulking increased shoot formation (branching) as compared with the control or 500 mg·L−1 benzylaminopurine treatments. The fourth experiment showed that applications of 500 mg·L−1 ethephon along with a 16-hour photoperiod during the bulking period improved shoot number and flowering of the finished crop. The combined results provide guidelines for producing a well-branched, flowering clematis crop within 1 year from the start of propagation to the time of the first open flower.

Influence of Stock Plant Growing Environment, Origin of Cuttings, Cultivar, and Rooting Hormone on Clematis Cutting Production and Propagation

“…It is possible that increased growth associated with high temperatures led to better accumulation of resources, resulting in a better quality of cuttings. Therefore, clematis stock plant management at 27 C, along with our previous research of long-day photoperiods on promoting shoot growth (Samarakoon and Faust, 2020), led to increased cutting production as well as better propagation performance.…”

“…For example, because propagation could be performed any time of the year, growers could schedule clematis successfully, depending on projected market dates. In combination with a 1-year production schedule for clematis (Samarakoon and Faust, 2020), the current research provides strategies to successfully propagate clematis within 8 weeks, thereby allowing for the integration of clematis into a more conventional greenhouse production schedule.…”

“…The reasons are the lack of availability of unrooted cuttings, poor rooting success compared with most annual and perennial species, and a production cycle from propagation to market that requires %2 years. Recently, a 1-year production schedule for clematis from propagation to finish has been developed (Samarakoon and Faust, 2020). Successful completion of this schedule relies on the availability of high-quality unrooted cuttings year-round.…”

“…Reductions in the sugar content were attributable to underground growth becoming sinks under short-day photoperiods (Sivaci, 2006). Long days and supplemental lighting promoted shoot growth and development of clematis when grown in a greenhouse (Samarakoon and Faust, 2020). Buds were apparently nondormant, and plants were not exposed to short days.…”