Effect of nitrogen, phosphorus and potassium availability on mother plant size, seed production and germination ability of Rumex crispus

Abstract

Rumex crispus is believed to be a highly nutrient-demanding weedy species that spreads mainly by seeds. However, the effects of nutrient availability on its performance and seed production have never been fully investigated. In this study, we investigated how plant size, seed production and germination were affected by the supply of N, P and K. In May 2008, a pot N, P and K fertiliser experiment was established in Prague (Czech Republic). During 2009, plant growth data were collected, and fully ripe seeds were tested for germination and N, P and K concentrations. Rumex crispus showed high phenotypic plasticity in plant height, number of leaves, leaf length and number of stems per plant in relation to N, P and K supply. Seed production per plant ranged from <2000 in the control and low P treatment up to almost 25000 in the high NPK treatment. More than 16000 seeds were produced per plant in all treatments where N and P were applied together. To produce a high quantity of rapidly germinating seeds, R. crispus requires a balanced N, P and K supply, as a deficiency of P and K together with a high N supply can result in the production of P- and K-deficient seeds (P and K <3gkg -1) with lower germination ability. In central Europe, at least some populations of R. crispus do not flower in the seeding year and are strictly monocarpic. Given the short lifespan and monocarpic character of the species, control is probably most effective if applied at the rosette stage, prior to the production of viable seeds. © 2012 The Authors. Weed Research © 2012 European Weed Research Society.