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Control of weeds in maize and wheat – Part 8: Goose grass

Category: WEED SERIES

Goose grass seedling.
Tufted goose grass.
Culm and seed.
Adult plant with green culms.

Scientific name: Eleusine corocana
Afrikaans name: Jongosgras, osgras
English name: Goose grass, rapoko grass

Short description

Goose grass is an annual tufted grass, growing up to 60 cm high. The grass has a strong and well developed root system. A characteristic of this weed is its powerful initial root development, which makes it so well adapted to the climate in southern Africa. Culms are often branched and kneed at the base and hairless. Leaves are up to 50 cm long and 1 cm wide, hairless and distinctively folded. Inflorescence is vivid light green and consists of two to ten one-sided spikes, arranged finger-shaped (dactylose) or half finger-shaped. Spikelets usually cross over each other and are also characteristically flat. Seeds (caryopses) are black, oval-shaped, up to 2 mm long and 1 mm wide. The surface is sharply ridged along the sides, across the whole seed.

Distribution

Goose grass is the most common grass weed of cultivated fields in South Africa. Because of the extended and vigorous root system, it is one of the most severe competitors with dryland summer crops. Most of the grass weed species’ seedlings look very much alike and it is sometimes difficult to distinguish between finger grass (Digitaria spp.), herringbone grass (Urochloa spp.), buffalo grass (Panicum spp.) and goose grass.

Control

Cultivation
Goose grass can be controlled by means of shallow cultivation in the seedling stage. Shallow cultivation will bring fresh seed to the surface and cause them to germinate, which will require more cultivation (hoeing). However, goose grass will continue to germinate during the summer season and hoeing is not an efficient way of controlling it.

Chemically
The most efficient method of controlling grass weeds is by means of herbicides. Goose grass is one of the most susceptive grass species with regards to pre- and post-emergence herbicides. Grass herbicides give the most effective control and where heavy infestations occur, control should be as complete and timeous as possible.

Various herbicides are registered for the control of goose grass in maize and wheat (Table 1 and Table 2). Strictly follow the specific instructions and dosages on each product label.

TABLE 1: Herbicides registered for the control of goose grass in maize.

Active ingredient Formula Time of application

acetochlor

700 g/litre

750 g/litre

768 g/litre

840 g/litre

900 g/litre

960 g/litre

Pre-emergence or early post-(crop)emergence

Early post-emergence of the crop, use as tank mixture with atrazine and/or terbuthylazine

Pre-emergence

Pre-emergence or early post-emergence, within three days after planting

Early post-emergence, use as tank mixture with atrazine and/or terbuthylazine

Read label instructions

acetochlor/atrazine/simazine

160/165/165 g/litre

Apply at or immediately after planting on a well-prepared seedbed

acetochlor/atrazine/
terbuthylazine

125/187,5/87,5 g/litre

150/225/225 g/litre

178,6/160,7/160,7 g/litre

250/225/225 g/litre

350/175/175 g/litre

Apply at or immediately after planting on a well-prepared seedbed

Apply within three days after planting, but before crop and weed emergence

Pre-emergence

Pre-emergence or early post-emergence, Apply at, or immediately after planting on a well-prepared seedbed

Pre-emergence or early post-emergence

acetochlor/EPTC

150/350 g/litre

Pre-emergence

alachlor

384 g/litre

480 g/litre

At planting or immediately after, within two days after planting

At planting or immediately after, within two days after planting

alachlor/atrazine

336/144 g/litre

Pre-emergence on a well-prepared seedbed within two days after planting

atrazine/mesotrione/
s-metolachlor

208,5/26,8/208,5 g/litre

Pre-emergence

atrazine/metazachlor/terbuthylazine

210/30/210 g/litre

Pre-emergence, within three days after planting

Post-emergence as follow-up application

atrazine/metolachlor

300/300 g/litre

Pre-emergence, within three days of seedbed preparation and planting

atrazine/metolachlor/terbuthylazine

174/252/174 g/litre

262,5/175/262,5 g/litre

Pre-emergence or early post-emergence

Pre-emergence or early post-emergence

atrazine/s-metolachlor

370/290 g/litre

Pre-emergence, apply at/or immediately after planting on a well-prepared seedbed

dimethenamid-P

720 g/litre

Pre-emergence, apply within three days of planting

dicamba/topramezone

160/50 g/litre

Early post-emergence, before six leaf stage, use in tank mix with atrazine or atrazine/terbuthylazine and Dash HC

EPTC

720 g/litre

Pre-plant, incorporate into soil, read the label

flumetsulam

800 g/kg

Pre-emergence, use only in tank mix with metolachlor or S-metolachlor

flumetsulam/s-metolachlor

20/630 g/litre

At planting on a well-prepared seedbed within three days after planting

glyphosate/mesotrione/
s-metolachlor

250/25/250 g/litre

Post-emergence, only on glyphosate resistant cultivars

mesotrione/s-metolachlor

83,3/416,7 g/litre

Pre-emergence

metolachlor

800 g/litre

840 g/litre

915 g/litre

960 g/litre

Pre-emergence on a well-prepared seedbed, within three days after planting

Pre-emergence, on a well-prepared seedbed, within three days after planting

Pre-emergence, apply on well-prepared seedbed, within three days after planting

Pre-emergence, apply on well-prepared seedbed, within three days after planting

metribuzin

480 g/litre

Post-emergence, apply on actively growing weeds after they have emerged to the four to six leaf stage

nicosulfuron

40 g/litre

240 g/litre

Post-emergence, when crop is in two to six leaf stage

topramezone

226 g/litre

Early post-emergence. Read label instructions

s-metolachlor

915 g/litre

960 g/litre

Pre-emergence on a well-prepared seedbed, within three days after planting

Pre-emergence, read label instructions

s-metolachlor/terbuthylazine

102,8/497,2 g/litre

312,5/187,5 g/litre

Pre-emergence, on a well-prepared seedbed

Early post-emergence, only to be used in a tank mix with Callisto

 

TABLE 2: Herbicides registered for the control of goose grass in wheat.

Active ingredient Formula Time of application

trifluralin

480 g/litre

Pre-plant, dosage depends on weed species


Always contact a reliable chemical advisor before applying any chemicals to ensure the correct dosage and specifications are adhered to.

Contact the writers at elbe.hugo@syngenta.com (Elbe Hugo) and deweth@arc.agric.za (Hestia Nienaber).