UPDATE: The jury has found Miss Harmon not guilty.

EARLIER: A MOWBRAY woman is contesting an allegation that she wounded her partner with a knife.

Rhiannon Alleshia Harmon, 20, pleaded not guilty to one count of wounding in the Launceston Supreme Court today.

In her opening address, Crown prosecutor Yolanda Prenc told the court that Miss Harmon became upset on April 28, 2013, after having a bad dream and started to cry, but her partner would not respond to her being upset.

Ms Prenc said that the accused became angry, threw objects at her partner and grabbed the man by his collar while dragging him off the couch.

She said that Miss Harmon told her partner to leave, but when he refused, she grabbed a knife and swung it at him, causing a "very deep'' wound to his arm.

Defence counsel Fabiano Cangelosi, in his opening address, said that the defence would dispute the Crown's allegations that Miss Harmon intended to cause the wound or that she acted knowing that the wound would be caused.

The Crown has called the complainant, an Ambulance Tasmania paramedic and a Tasmania Police constable to give evidence.

The trial, before Justice David Porter, continues.