8 August 1997

Drilling date not vital consideration

SCOTLAND aside, where the aim is to get most crops in by mid-August, drilling date is not critical, says Mr Gillings.

"I recall one Northants grower who redrilled on Oct 21 and still got 28cwt/acre. Clearly I am not advocating that anyone sows that late. But a target of the end of August/beginning of September is OK for most farms. If you go beyond the first week in September good seed-beds become even more important."

In theory seed rate should be based on plant numbers. "But traditionally, farmers like to see a good crop going into winter, mainly to deter pigeons, so they tend to use a bit more than they need."

That goes against initial suggestions from Notts University research that best yields come from thinner crops, he acknowledges. "But at least they then have a stand to play around with, and the cost of the extra seed is not great.

"I reckon 70-80 plants a sq m at the start of winter, ideally with six to seven true leaves each and not a weed in sight, is about right to allow for some losses. 40 plants in the spring is still perfectly adequate for a 30cwt/acre crop."

For conventional varieties that should be achieved by sowing 7kg/ha (6.3lb/acre).

Hybrid seed rate

The extra vigour of hybrids merits about half that. "For Synergy we are talking about 3kg/ha and for the newer fully restored Artus and Pronto you could even go down to 2.75kg/ha."

But the lower rate for the hybrids makes attention to seed-bed even more critical, he suggests. "Some of the early problems with Synergy were often self-inflicted. After all only 20% of the seed is the Falcon pollinator. That is not a lot."

Ensuring it all grows and emerges evenly is vital, he says. "Broadcasting can work with conventional varieties. But I would not recommend it for hybrids.

"Once it is in you can roll, roll and roll. Moisture conservation is of paramount importance."

At current prices a small amount of nitrogen fertiliser, no more than 20-30kg/ha (16-24 units/acre) at sowing, can easily be justified to boost autumn growth and rooting to help crops withstand spring drought, he suggests.

Last years dry conditions refocused attention on germination. "Seed dressings can inhibit moisture uptake and a number of growers questioned whether they needed them." For those who believe the risk of drought outweighs that from flea beetle United Oilseeds can offer untreated seed of some varieties at a discount of 50p/kg.