Semi-dwarf will be huge

21 July 2000

Semi-dwarf will be huge

By Shelley Wright

SEMI-DWARF oilseed rapes will completely replace conventional varieties within 20 years, a leading rape breeder predicts. But agronomy advice will need developing to make the most of them.

The first such variety, Lutin, seems to defy lodging, regardless of seed rate or how much nitrogen is applied, CPB Twyfords John Blackman said while inspecting plots run in conjunction with Scottish Agronomy near Kinross last week.

"I see this kind of variety completely replacing conventional type rape in, say, a 20-year time-frame. It may take a while to become established, just as semi-dwarf winter wheat did. People found they got more disease and they didnt know how to manage them.

"But the agronomy developed in parallel with the varieties and we see that happening exactly the same with rape."

For too long, oilseed rape has been seen as a crop that can be thrown into the ground then harvested to collect area aid payments, he says. "But those economics dont add up and are just not sustainable. If farmers are to survive they have to squeeze every bit of profit out of every bit of the rotation. There is no space for a loss making crop."

Plant breeders had made little progress in improving the yield potential of oilseed rape to date, he adds. "But maybe now we have a breakthrough. This type of semi-dwarf variety has the ability to take more fertiliser and will, perhaps, benefit from high fungicide inputs, like cereals do."

So far, trial work indicates that 300-350kg of nitrogen and seed rates of 40 seeds/sq m provide good results. The trials are also comparing desiccation with natural ripening, says Huw Phillips, director of Scottish Agronomy.

Lutin sown on Sept 3 shows the variety has the potential to be an early Sept sown variety, allowing it to follow winter barley.

With average height of just 104cm and virtually no stem Lutin can be sprayed and harvested with conventional machinery. It will not be available commercially until 2001 at the earliest. &#42

Lodging like this could be a thing of the past for Scottish rape growers if new semi-dwarf Lutin makes the grade, say Huw Philips of Scottish Agronomy (left) and John Blackman of breeder CPBT.

SEMI-DWARFOSR

&#8226 104cm tall, resists lodging.

&#8226 New agronomy needed.

&#8226 Existing equipment OK.

&#8226 Commercial seed in 2001?