Despite good growing conditions towards the end of the season, SunRice has estimated its growers will harvest less than 70 per cent of the last crop, down to 800,000 tonnes from 1,161,000 tonnes last year.

Benerembah rice grower Hayden Cudmore was relieved the past two weeks have been sunny and the muddy ground dried enough to begin harvest, albeit slightly delayed.

"We had a very poor start to the crop with cold and windy weather through October and November which was bad for establishment," Mr Cudmore said.

"However, since Christmas we've had some good growing conditions that have really compensated and it's translating to pretty good yields.

"There is a bit of bogged up ground but most of it will be fine to sow a winter crop into, which will probably be hard wheat."

SunRice's general manager of grower services Mike Hedditch said there wasn't enough water available to growers in the Murrumbidgee Valley at planting time to match last year's result.

"Rice harvest is under way but was slowed due to several significant rain interruptions," Mr Hedditch said.

"This is the first wet harvest in the Riverina region since 1999, however apart from delaying harvest, the rain has been welcomed by growers and will not cause major problems for the crop.

"At close of business on April 22, 2014, 242,517 tonnes of paddy had been received at 16 Australian Grain Storage depots across all growing regions."

SunRice's rates were significantly higher for all varieties than the first payment rates for the previous crop, at $276 per tonne for SunRice's premium Sushi variety Koshihikari and $200 per tonne for the medium grain variety Reiziq.