Weeds - Grass Weeds Information and Photo Gallery

Wild oats

Appearance

Wild oat (Avena fatua) closely resembles its domestic relative. The stems are tall - around 60-180 cm high. The leaves are up to 60 cm long, green and hair free. The flower spikelets usually have three florets hanging in loose panicles and develop during the summer. The sturdy mature plant can reach up to 120 cm tall. It is an annual grass and is primarily a weed in spring-seeded small grains. Panicles are nodding and softly pyramidal in shape.

Occurrence and spread

Wild oats is a common weed on arable land and is widely distributed in cultivated regions of the UK. It flowers and produces seed from June to August. Seeds can be dormant at least 10 years. Seeds germinate between autumn and early spring. Wild oats will be seen appearing just above the crop canopy from the middle of June.

Control and management

Wild-oats are the most competitive of all weeds. Yield losses are greater the longer they remain in the crop, and just one wild-oat/2mē causes a 2% decrease in yield. Therefore, the earlier herbicide application is made the better. Earlier sprays not only give the greatest yield response, but also the highest level of control – since smaller weeds are more susceptible. Also, smaller weeds require a lower herbicide dose. Leaving wild-oats until flag leaf – although tempting because infestations are easier to see – means costly fire brigade treatments are needed.

Seed dormancy is induced by burying via deep tillage.

Current control methods are chemical. Labelled compounds include quizalofop which can be used on a wide variety of crops including OSR, field beans, linseed sugar beet and peas. Clodinafop-propargyl (Topik) has been shown in field trials carried out by ADAS and others has been shown to be very effective. Economic control threshold is approximately 1 plant every 2 square metres. Seek advice from your BASIS qualified adviser.

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© University of Hertfordshire, 2011