A roadside fire, which occurred near a substation and threatened a barley field, is thought to have been caused by a power line fault.
The Masterton fire crew and a Carterton tanker were called to the fire, near the Gladstone substation on the Masterton-Martinborough road, at 1pm on Sunday.
Carterton volunteer fire chief Wayne Robinson said the fire burned about 50 metres of grass on the side of the road and part of a barley field.
"The power line shorted out and set fire to the grass," Mr Robinson said.
"If the wind had been up and the paddock of barley had been a bit drier, it could have been a totally different story."