The state government's boost to loosen THC levels in the hemp industry could not have come at a better time for Busselton hemp farmers.

Vasse Valley owner Bronwyn Blake said the amendment to allow hemp to be grown with a THC content of up to one per cent was fantastic.

Vasse Valley hemp farmers Bronwyn and Chris Blake.

Hemp farmers were restricted to the Industrial Hemp Act, which only permitted hemp with a THC content below 0.35 per cent.

Ms Blake said that while most hemp varieties were bred to have low THC levels, WA hemp farmers were at risk of losing their crop if the plants tested slightly over the limit.