| Arundo donax L. (Poaceae), a pestiferous riparian weed, was grown hydroponically in a greenhouse, in soil-filled pots, and in the field to determine changes in growth and nitrogen partitioning and, under nitrogen limitation, to determine critical tissue nitrogen concentration. Soil-filled pot and field plants were sprayed with glyphosate herbicide to determine if application during a period of low tissue nitrogen concentration resulted in a lower post-spray regrowth rate.; There were significant changes in growth and nitrogen partitioning among tissues as hydroponic plants grew. Green leaf blade nitrogen concentration decreased during the summer for plants grown in pots and in the field. There was significant variation in minimum nitrogen concentration among tissues and growth treatments.; There was no nitrogen concentration effect on regrowth rate for plants sprayed during a three month period of 1998; glyphosate allowed less than 0.5% regrowth when compared to a control. |
