Broad-leaved paspalum
  • Last updated:
  • 04 Mar 2022

The problem

Broad-leafed paspalum (Paspalum mandiocanum) is a robust grass that is unpalatable to cattle and horses. Graziers should be aware that it can invade pastures and replace palatable species. It will also grow in dense shade, with the possibility of dominating the ground layer of closed forests.

Originating from Brazil, this species is drought tolerant and grows rapidly after rainfall. It grows faster than, and can easily out-compete, more palatable pasture species. The tussocks are flat and spread outwards, smothering desirable but less competitive plants. It produces a large number of seeds, which have a high rate of germination. Seed can be spread as a contaminant of equipment, vehicles, animals, soils, mulches and other materials.

Description

The mature leaves are more than 10mm wide, bright (emerald) green, have a crinkled margin and a spreading habit. The lower 70-100mm of the leaves is maroon, burgundy or brown.

Flower stems can be over 1m tall with up to 10 flower/seed stalks growing alternately down the stem. Ripe seed heads hang at about 45° if the stem is upright. Individual tussocks can grow to 1m wide and easily spread sideways, as the stems contacting with the soil will form roots.

Plants grow in open pasture, along roadside verges, in bush margins and in deeply shaded areas in forests. Tussocks have a high degree of tolerance to mowing.

It was found in cattle paddocks on the Atherton Tablelands in 2002 and on horticultural properties around Bellthorpe and Booroobin 2004. It has since been found on roadsides and properties across and around the Blackall Range region.

Management

Seedlings and smaller plants can be hand-pulled, bagged and disposed of at the tip or composted. Gloves should be worn, as the leaves and seed heads may cause skin irritation. Larger infestations may require chemical control. For general weed control, broad-leafed paspalum can be foliar sprayed using a glyphosate 360g/L herbicide (eg Weedmaster Duo) at a rate of 10ml per 1L of water.

Care must be taken, as the herbicides will damage other non-target plants if they are accidentally sprayed. The optimum time for spraying is in spring when the plants are actively growing.

Read the label carefully before use and always use the herbicide in accordance with the label directions.

For additional information on these weed species please contact council.