Digitaria spp.

Summer grass

Other common names:

Crabgrass.

 

Description:

There are two species of summer grass in Australia (Digitaria cilaris and Digitaria sanguinalis) and there is minimal difference between the two. The annual grass weeds are tufted or mat forming that inhibit a wide range of soils; although its natural habitat is sandy soil and loams (Skerman and Riveros, 1990). Summer grass has poor drought tolerance and can grow in full sun and shade. The weed can be found in any turfgrass species as an undesirable weed and can grow to 30 cm tall and spread to 1 m wide if left unmown. The slender culms (stems) show a distinct red purple colour, ascending from a decumbent base. The relatively wide leaves which can be greater than 5 cm long are soft and hairy on the underside of the foliage; the sheaths are also hairy and the ligules are papery to the touch. The stems often have a red to purple tinge to them. The stolons of the plants root down at nodes which can dramatically increase the area the weed encompasses. Inflorescence is more or less terminal, to 15 cm, slender, spreading, 2 to 10 per inflorescence (Drake et al., 1994). Summer grass flowers in summer and autumn and the seed can remain dormant in the soil for several years before germinating. Summer grass has shallow fibrous roots.

 

Distribution:

A widely distributed weed found in the tropics, subtropical and temperate regions of Australia.

 

Lifecycle:

Summer grass is an annual grass weed that spreads by seed. Flowering and therefore seed development occurs in late summer and autumn ensuring an abundant infestation during seasons thereafter, unless a preemergent program is introduced. When temperatures are optimal, summer grass emerges 2 to 3 weeks earlier than crowsfoot (Eleusine indica).

 

Environmental triggers:

  • Temperature: Seed germination occurs when soil temperatures are between 12°C to 15°C for 14 continuous hours at a 10 cm depth below the soil surface. Rapid growth and development is observed during hot summer months. ·
  • Humidity: Summer grass thrives on high temperatures and humidity. ·
  • Rainfall/water presence: Weed germination is best when there is adequate soil moisture. ·
  • Frost: Flowers until frost (McCarty et al., 2008). A hard frost can kill summer grass.

 

Control options:

  • Pesticides: See available tabs below for registered products. Use as per label instructions.
  • Integrated Pest Management (IPM): Use a combination of approaches listed on this page.
  • Cultural: Nil.
  • Mechanical: Nil

 

Disclaimer:

Turf Finder or its developer accepts with no responsibility for any consequences whatsoever resulting from the use of any information or product(s) listed herein. Products are to be applied as per label instructions.

Control Options

Oxafert 16-2-6

 

Barricade

 

Embargo

 

Oxafert 16-2-6

 

Barricade

 

Embargo