2 April 1999

Hybrid OSRs worth extra cost – breeder

HYBRID oilseed rape is still worth the extra seed cost, says CPB Twyford, provided growers achieve the full potential of such varieties.

On-farm yields of Pronto have averaged 0.4t/ha (3cwt/acre) more than conventional varieties over the past two years, worth £48/ha at current prices. That easily makes up for the £20/ha extra seed cost of hybrids, says marketing manager, Mary Munley.

"Whatever the crop price falls to the margin in terms of covering seed cost is there."

But over-thick crops have caused disappointing yields for some growers and problems with NIAB plots in the past. They were planted at 120 seeds a sq m compared to the companys recommendation of 60 seeds a sq m.

"A lot of farmers have been buying hybrid seed and not thinking how to get the most out of it. Establishing hybrids properly is the key," says technical director John Blackman. If that is done, newly recommended variety Gemini could break the 6t/ha (49cwt/acre) yield barrier, he reckons.

Made up of 80% male sterile seed and 20% restored hybrid pollinator Artus, the so-called super varietal association tops the NIAB list for yield. Economic yield, allowing for oil content, matches Pronto, is 2% higher than top in-bred variety Escort, and 9% ahead of market leader Apex.

Recommended retail price is £190 a pack, compared with Prontos £180, says Ms Munley. Packs for both varieties contain a minimum of 1.8m viable seeds, enough for 3ha (7.4 acres) at the recommended rate.

Some growers are succeeding with seed rates even lower than the 60/sq m, notes operations director Theo Labuda. "But it takes a brave man to do that."

Blocking off alternate coulters can help with such low rates. Seed producers have achieved good crops at 30-36cm (12-14in) row spacings, notes Mr Blackman.

But good seedbeds are essential, and growers should wait for moisture before planting. "It should be like the seed-bed in your garden for vegetables."

That means broadcast establishment techniques may not be suitable, especially if harvest is early.

l1999 NIAB trials have hybrid varieties sown at 70 seeds a sq m. &#42

HYBRID HINTS

&#8226 Extra yield outweighs seed cost, even at reduced rapeseed prices.

&#8226 Grower expertise required.

&#8226 Gemini to break 6t/ha barrier?

&#8226 Synergy still best bet for Scotland.

OSR drop expected

Plant breeder CPB Twyford expects a knee-jerk reaction to Agenda 2000 by oilseed rape growers. Crop area is expected to fall by 10% this autumn, but will recover back to 1999 levels by 2002 as growers will still need a break crop. Take-all seed dressings will not be sufficient to overcome the second-wheat syndrome, it says.

Beware pollen beetle

Growers should check pollen beetle numbers now, especially in varietal association hybrids such as Synergy or Gemini, says CPB Twyfords Liz Williams.

"The pollen beetles do find the pollen bearing plants," she warns. Threshold to treat is one beetle per five plants at the green bud stage, much lower than the 5-15 per plant for in-bred or fully restored hybrids.