Summer and Autumn Growth of Rhizomatous Birdsfoot Trefoil

Abstract

A new population of birdsfoot trefoil (Lotus corniculatus L.) with rhizomes (RBFT) has been developed for greater persistence. No study has compared RBFT with a standard, non‐rhizomatous cultivar of birdsfoot trefoil (BFT). Objectives were to: (i) compare RBFT with BFT for differences in shoot and root mass and total nonstructural carbohydrate (TNC) concentration of taproots in both clipped and non‐clipped situations and (ii) describe rhizome production of clipped and non‐clipped RBFT. ‘Norcen’ BFT and RBFT were grown in field plots near Columbia, MO, in 1994 and 1995. The study had four treatments: non‐clipped RBFT, clipped RBFT, non‐clipped BFT, and clipped BFT. Each treatment was replicated four times in a randomized complete block. Plots were sampled biweekly for shoot and root mass and taproot TNC from early‐July until the first killing frost in October. In addition, length, mass, TNC, and number of rhizomes per plant were recorded for RBFT. From mid‐September until the final sampling, the shoot mass for RBFT was about half that of BFT; however, RBFT's shoot mass was less affected by clipping than was BFT's. Taproot TNC was 20 to 40 g kg−1 greater for RBFT than BFT throughout both growing seasons. Nearly all RBFT plants exhibited rhizomes by mid‐October both years. Clipping RBFT plants did not affect rhizome growth. Rhizome TNC concentration increased steadily during autumn, with a final concentration of approximately 220 g kg−1 The failure of clipping to decrease rhizome production, combined with higher levels of below‐ground TNC, may give RBFT the ability to withstand frequent defoliation.