February 3, 2021
Enhanced iFarm establishment approach restores faith in Oilseed Rape
Putting all the pieces of a well-researched oilseed rape establishment jigsaw in place has paid handsome dividends for Jim Farquharson and his Agrii agronomist, Todd Jex at the Dorset iFarm near Blandford this season.
Unlike 2019 when only 33 ha of the 70ha of OSR they planted survived to harvest, all 92ha of Eastbury Estates’ 2020 plantings have established strongly.
Indeed, they have gone into the winter with headland-to-headland stands for almost the first time ever; and, thanks to relatively late drilling, without excessive top growth or significant CSFB larval burdens either.
“Last season wasn’t pretty,” recalls Mr Farquharson who runs the family’s 400 ha arable business alongside other enterprises. “As well as losing over half our crop, the fields we harvested averaged just 3.3t/ha. Excluding the badly-damaged areas, though, they did 3.9t/ha despite the appallingly wet winter and bone-dry spring; which is about we normally average.
“This convinced us the crop was worth sticking-with, providing we could get it established reliably. It’s long been our preferred cereal break and best entry for wheat. On top of which, alternatives like peas are completely out with our level of downland flints, and beans were a disaster last year.”
Increasing their OSR area by almost a third after last season’s experience wasn’t a decision the team took lightly. Indeed, they only took it armed with a clear set of establishment improvement imperatives (see box).
|Dorset iFarm 2020 OSR Establishment Improvement Imperatives
“As part of the iFarm network we’ve learnt a lot from the local trials we’ve been involved in together with the work of my research colleagues on other sites across the country,” says Todd Jex. “There were a lot of things we got right last year. But we didn’t put enough of the pieces of the jigsaw in place to deal with the ‘double whammy’ of intense flea beetle pressure and serious lack of September moisture.
“For instance, we used a buckwheat companion but sowed it with the crop. We left a reasonable cereal stubble but disturbed too much of it at drilling. And we used a starter fertiliser but didn’t have the ability to place it with the seed.
“This autumn we air-seeded the buckwheat into our barley before harvest so it was well enough grown to shelter the OSR we drilled three weeks later in the last week of August.
“Then we employed Dutch coulters on the newly-acquired Horsch Sprinter to minimise soil movement and used the GPS to drill the seed accurately between the rows of good length stubble, leaving them standing well. The new drill also enabled us to place a specially-formulated AgriiStart fertiliser giving 30kg/ha of nitrogen, protected phosphate and added boron just below it for the best possible early growth.”
“We also made sure to use only a hybrid proven to be fast-developing in the autumn as well as vigorous,” Mr Farquharson adds. “I made the mistake of trying a new variety touted as having ‘excellent vigour’ as part of our mix last year and it showed itself to have nothing of the sort in practice.
“In the past we have tended to drill in mid-August to minimise damage from our ‘feathered flea beetles’ (the red-legged partridges put down for the Estate’s well-regarded shoot). Even though we had enough moisture, we deliberately held-off this season’s drilling until the end of the month to reduce the risk of particular problems with flea beetle larvae associated with earlier sowings. Nor were we tempted to increase sowing rates from the 50 seeds/m2 we’ve long found give us the most productive canopies.”
Only having achieved the start they wanted from their enhanced establishment approach –
and, it has to be said, much more favourable early growing conditions – this season, have Jim Farquharson and Todd Jex been happy to really invest in the crop to take advantage of its potential.
To deal with weeds in the absence of a pre-em (foregone to avoid any early growth check as well as to contain establishment costs) they applied an early post-em combination of Ralos (aminopyralid + metazachlor + picloram) and Belkar (arylex + picloram). This also helped the buckwheat on its way, leaving a nice clean crop growing strongly into the winter.
Unlike many crops sown earlier and at higher seed rates, their OSR wasn’t too growthy either. So, they didn’t have to use an autumn PGR, aren’t worried about winter hardiness and are well-placed to have a strong, thick-stemmed canopy they can manage most productively to harvest.
“Interestingly, putting all the pieces of the establishment puzzle into place seems to have protected the OSR as effectively from our partridges as it has from the flea beetle,” reflects Mr Farquharson. “There’s plenty of water to go under the bridge yet, but this season is really beginning to restore our faith in the crop.”