Geoff Rethus windrowed his biotechnology canola crop just out of Horsham on Wednesday.

Mr Rethus said he was cutting the crop for harvest in about seven to 10 days' time.

He said cutting the crop would allow it to ripen evenly, with varying moisture levels in canola that had grown on paddock rises and in low- lying areas.

Mr Rethus said he was thrilled with how the crop was progressing.

He said compared with his conventional canola crop growing at Noradjuha, the GM canola crop was much cleaner.

"It's helped us get on top of our weeds," Mr Rethus said.

"It looks like it's going to yield well."

Mr Rethus said he could start harvesting lentils as early as next week.

He said barley crop quality would vary but he hoped a Noradjuha crop would make malt grade.

Victorian Farmers Federation grains group vice-president Andrew Weidemann also windrowed his GM canola crop at Rupanyup on Wednesday.

"It's looking quite good but we'll wait and see, the header tells the story," Mr Weidemann said.

"The crop's looking clean, there are no weeds. The variety looks like it can handle the conditions reasonably well.

"Everything is hard to assess without the rain we missed in August and September."

Mr Weidemann said he was hoping to start harvesting earlier crops such as lentils and barley today.

But Mr Weidemann is concerned about low grain prices. He said he was planning on storing grain and waiting for a price improvement.

"Grain prices are below the cost of production," he said.