Rhizome Weight and Number of Sectioning per Rhizome Determine Plantlet Growth and Propagation Rate of Hemerocallis citrina Baroni in Cutting Propagation

Abstract

Rhizome cutting is prevalent in propagation for Hemerocallis citrina Baroni. This study aimed to reveal the influence of rhizome weight on plantlet growth, and evaluate a new cutting protocol. Three levels of rhizome weight (big (BR), medium (MR) and small (SR)) were compared by measuring plantlet growth four times during cutting propagation. Sectioning rhizomes longitudinally along shaft axis of crown into 2, 3 or 4 parts (S2, S3 and S4), was tested on rhizomes with two bud sizes (Large bud (LB), Small bud (SB)). Propagation coefficient, the number of plantlets obtained per rhizome, kept similar regardless of rhizome weight, while S3 and S4 increased propagation coefficient. Rhizome weight changed the relative growth rates on different dates. SR resulted in lower aboveground dry biomass, leaf area, total fibrous root length, relative total fibrous root length growth rate and N deficiency compared to BR. Sucrose concentration in rhizome decreased with time and fructose concentration was lowest in MR at the end of experiment. Aboveground dry biomass and total fibrous root length were lowest in S4, followed by S3 and S2. Rhizome weight and number of sectioning per rhizome influence cutting propagation, and sectioning rhizomes into three pieces has higher propagation coefficient and less retardation on growth. According to N deficiency in plantlets during the propagation, N fertiliser is probably needed during cutting.