Barnyard Grass

Echinochloa-crus-galli

Though barnyard grass (Echinochloa-crus-galli) is mainly found on the North Island it can now be found on the South Island as far south as South Canterbury. Barnyard grass germinates in the spring when temperatures increase. Barnyard grass is very competitive and invades a range of crops. When small, barnyard grass can be identified by its upright habit, rolled leaves and lack of ligules or auricles. When seed-heads are present they are quite distinct being open and with dark brown seeds.

Related Pests

Annual Poa

Poa annua

Annual poa (Poa annua), also known as annual meadow grass, is a fast growing annual grass found throughout New Zealand in a wide range of crops. While individual plants tend to be small, populations of this grass weed tend to be large and they then compete for light, nutrients and water. Poa annua is best identified by the boat shaped tips to its leaves and the two parallel veins (often referred to as tramlines) that can be seen if the leaf blade is bent backwards. Germination takes place throughout the year and is set very quickly meaning populations soon increase.

Chickweed

Stellaria media

Chickweed (Stellaria media) is a widespread, very resistant weed, it is found in the North and South Island in areas of cultivated land and roadsides. Commonly seen in winter, it does not favour drier conditions. It is a problem in small grain crops such as barley, causing up to 80% yield losses. It a low growing spreading annual (up to 40 cm) with, light green soft leaves, (lighter underneath) up to 2 cm long. The leaves are in opposite pairs on hairy stalks. Flowers are white, about 1 cm in diameter, with 5 deeply divided petals that appear to be 10 petals. Chickweed flowers and sets seeds simultaneously. The seeds are contained in green egg-shaped capsules, and one plant produces about 15,000 seeds, which remain capable of germination in the soil for up to 5 years.

Speedwell

Veronica persica

Speedwell (Veronica persica) is very common throughout New Zealand. Also known as scrambling speedwell, it is a sprawling, many stemmed annual with blue flowers. Germinates in both autumn and spring, so can be a problem weed in arable and brassica crops.