Propagation of Reed Canarygrass (Phalaris arundinacea L.) from Culm Segments1

Abstract

Development of hybrid cultivars of reed canarygrass (Phalaris arundinacea L.) necessitates vegetative increase of clones selected as parents. Our objectives were to determine the effects of genotypes, stage of growth, and treatment with ethephon (2‐chloroethylphosphonic acid) on the establishment of stands from nodes of reed canarygrass culm segments. We established 12 genotypes (clones) from fixed quantities of culms with attached leaves chopped into 10 cm lengths. Satisfactory stands of all clones resulted when at least 0.4 kg/m2 of chopped material was covered with soil and irrigated, provided that culms were from sufficiently mature plants. Differences among clones in the number of established plants were highly significant.Maturity affected establishment, in that cutting of culms at or before anthesis usually resulted in stand failure, whereas cutting at postanthesis to seed shattering stages resulted in satisfactory stands. Nonheading clones with 3.5‐month‐old culms also provided viable nodes. More shoots with larger roots were established from basal nodes than frcm apical nodes of culms at various growth stages.Treatment of chopped culms of one nonheading clone with ethephon at 100‐to 1,000 ppm rates resulted in higher stand density than that of the untreated check. Ethephon suppressed density when one clone was similarly treated at the seed shattering stage.Our results indicated a general lack of relationship between tillering capacity (expressed as plant width) and stand establishment from culm sections of 64 clones (r = −0.20). The results suggested that tillering and nodal activity must both be considered before planting rates can be established for parent clones intended for field‐scale crossing in hybrid development.