Oilseed rape growers don’t always need to sow all the seed they order and should pay more attention to drilling by seed number and recognising increasing phoma challenges.
As harvest results filter in those are key messages from Masstock’s Best of British Oilseeds initiative.
“Overall, winter oilseed rape seems to have had a good but not record-breaking year,” says the firm’s David Neale.
“But trials and grower feedback shows that there is a lot more variability than usual.
We are finding that as well as seed-bed quality and seed rate the other big factor has been phoma, especially where rotations are getting tighter.”
Barrel and ES Betty, otherwise good varieties with weak phoma resistance, have performed relatively poorly.
“It was no surprise to see Barrel second from the bottom of the list at the HGCA’s Oxon site.”
Last season’s growing conditions favoured low biomass conventional varieties such as Castille, non-recommended Caracas and phoma-resistant ES Astrid, says Mr Neale.
“We had a lot of good autumn growth, plenty of residual nitrogen and a wet spring followed by a short flowering period, and a lot of crops accomplished our 5t/ha target.”
Hybrid Excalibur performed consistently well irrespective of sowing date, with the added advantage of being a week earlier to harvest.
That is an important issue in trials data, as the variety will lose yield if combined too late, he points out.
Another, Excel, with top phoma resistance rated at 8 also did well in BoBO trials.
“Although like other bigger, taller hybrids they seemed to suffer under the drought pressure in June.”
The notion that they are deeper rooting and so could withstand dry weather better is misplaced, he believes.
“It is more appropriate to position them for more difficult sites and later drilling, as their speed of development and recovery from pigeon damage is much better than the conventionals’.
Where farmers acted on our advice and reduced seed rates to sensible levels, so that they achieved around 60 plants/sq m in the spring for conventional varieties and rather less for hybrids, there have been quite a lot of 2t to 42cwt/acre crops.
“Where they got a good branching structure instead of a load of thin, dense upright stems their crops really shone through.”