Effect of height of cut on translocation of C-14-labelled assimilates in Eragrostis curvula (Schrad.) Nees

Abstract

A pot experiment was conducted in the glasshouse to determine the effect of three heights of cut on translocation of C-14-labelled assimilates in Eragrostis curvula cv. Ermelo. Autoradiographs revealed that to produce regrowth plants defoliated to a height of 7,5 cm did not draw on their reserves significantly and that both new growth and stubble were able to maintain a continuous supply of assimilates to the roots after defoliation. In contract, in plants defoliated to 2,5 cm all assimilates were retained in the labelled tiller to sustain new growth. Results from plants defoliated to 5,0 cm revealed the same patterns as for plants defoliated to 7,5 cm, although it was clear that smaller amounts had been translocated. These results indicate the practical importance of not defoliating E. curvula too low.

Keywords: cutting heights|translocations|C-14 (carbon 14 isotopes)|assimilates|experiments|glasshouse studies|defoliations|autoradiographs|regrowth vegetation|growth|stubbles|roots|carbohydrates|grasses|plants (ill)