Mechanical weeding of Rumex obtusifolius L. under different N, P and K availabilities in permanent grassland

Abstract

In Europe, Rumex obtusifolius L. is the most problematic grassland weed species, especially under the conditions of organic farming. The aims of this study were (1) to investigate the effectiveness of repeated mechanical weeding of R. obtusifolius from the permanent sward, cut two or three times per year, by digging the plants out from 5 cm below the soil surface, and (2) to test the effect of nutrient availability on the effectiveness of mechanical weeding. In 2007, the manipulative experiment was established on permanent grassland infested by R. obtusifolius using the following fertilizer treatments: control, P, N, NP and NPK. Plants of R. obtusifolius were removed eight times during three vegetation seasons. No significant decrease in the density of R. obtusifolius was recorded after three vegetation seasons and density was not significantly affected by fertilizer treatment. The cover of R. obtusifolius decreased slightly, but significantly, over the study period from 7.5% to 4.5%. The cover of R. obtusifolius was only marginally affected by fertilizer treatment. Mechanical weeding by digging the plants out from 5 cm below the ground is not a sufficient method of control for R. obtusifolius in infested fertile grasslands, even when applied eight times during three vegetation seasons.

Effects of management intensity and soil chemical properties on Rumex obtusifolius in cut grasslands in Lower Austria

“…At site 3, the population density even gained about 50% (Table 3) of the initial infestation in all treatments during the experiment. The high resilience of the weed can largely be attributed to the root-system of established plants which can store huge amounts of reserves (Bohner 2001;Strnad et al 2010).…”

“…In organic farming, synthetic herbicides are rejected, and removing or destroying the R. obtusifolius roots manually or mechanically is very labour and energy intensive. Strnad et al (2010) could show that, in fertile grassland, even repeated weeding of the plants 5 cm below the soil surface had no decreasing effect on R. obtusifolius infestation. The plant regeneration from underground organs was very successful and was not affected by fertiliser treatments (NPK).…”

“…The plant regeneration from underground organs was very successful and was not affected by fertiliser treatments (NPK). Regulation methods designed to destroy the below-ground plant parts by ploughing or milling can even promote rhizome multiplication and therefore the abundance of the species (Zaller 2004;Strnad et al 2010). An ecosystemic strategy for R. obtusifolius control requires a spectrum of control measures, individually combined for each farm.…”

Effects of nutrient availability on performance and mortality of Rumex obtusifolius and R. crispus in unmanaged grassland

“…obtusifolius L. (broad-leaved dock, hereafter referred to as R. obtusifolius) in temperate grasslands has received high research attention (Zaller 2004(Zaller , 2006Bayhan et al 2006;Van Evert et al 2009;Gilgen et al 2010;Stilmant et al 2010;Strnad et al 2010;Hrdličková et al 2011;Hann et al 2012). This is because R. obtusifolius is considered to be one of the most troublesome grassland weedy species worldwide due to: (1) its general avoidance by grazing livestock, especially cattle and horses; (2) its negative effects on forage quality, as it induces health problems if eaten in high quantity and (3) its negative effects on biomass production of desired forage species by competition for space, water and nutrients (Zaller 2004).…”

Drought Stress alters Solute Allocation in Broadleaf Dock (Rumex obtusifolius)

“…Since the control of broadleaf dock is very difficult and laborious (see Strnad et al (2010) for 35 a summary of available methods) an increase in the abundance would cause additional costs 36 for weed management.…”