Many more farmers are trying out the new oilseed rape Clearfield system this year, mostly in a bid to rid themselves of difficult to control weeds such as charlock, hedge mustard and runch or as a prophylactic approach to making sure their seed sample has low erucic acid levels. But some farmers are hesitant to step into this system because of the myth that the yields of Clearfield varieties are still thought to be lower than non-Clearfield ones.
“That may have been the case in the early days of development but no more,” says Neil Groom, technical director for Grainseed. “If growers want all the advantages of the Clearfield system plus yield, then they must choose the Grainseed Clearfield variety, Es Aquarel CL.” Neil reports that in two independent NIABTAG trials this year 2017, just reported hot off the combine, Es Aquarel CL was the top yielding Clearfield variety.
“In a NIAB/TAG trial in Norfolk it yielded 4.3 t/ha or 104% of the site mean- this was the highest yielding Clearfield variety on the site where the range for CL varieties was 3.86 t/ha to 4.3t/ha. The yield benefit of 0.44 t/ha for Es Aquarel CL will make a significant impact to profits. Other rape varieties on the same site yielded 4.18 t/ha, showing that Clearfield varieties are no longer lagging behind in terms of yield,” he says.
“Last year Es Aquarel CL also yielded above other Clearfield varieties. In Norfolk it yielded 5 t/ha (105%) compared with DK Impression which gave 4.7 t/ha and the non-Clearfield variety DK Cabernet which yielded 4.6 t/ha or 98%. So in two contrasting years Es Aquarel CL excelled itself in terms of yield against other well known Clearfield varieties and other non-Clearfield ones, too,” says Neil.
He goes on to explain that Clearfield is a unique system for oilseed rape that combines hybrid seed varieties and high quality BASF herbicides for a very effective way to approach weed control. Using conventional breeding techniques, varieties have been bred to tolerate Clearfield herbicides. By applying these herbicides, Cleranda and Cleravo (which is a non metazachlor option) post-emergence, all weeds and volunteer rape can be controlled. “This means growers can use Clearfield as a management tool, bringing fields back into rotation and allowing rape to be grown profitably where it would have been difficult or impossible to grow using any other system.” he comments.
Neil Groom says by growing Es Aquarel CL growers get the best of all worlds, benefitting from the advantages of Clearfield whilst growing a high yielding variety.
Neil also points out that Es Aquarel CL has early maturity like Es Alegria which means it can be in the barn well before other varieties, helping with heavy workload at harvest and giving more time for preparation for drilling following crops and/or dealing with black-grass. Es Aquarel CL has high resistance to lodging, good stem stiffness and excellent multi-gene resistance to disease. It has an 8 rating against Phoma stem canker and a 6 against Light Leaf spot. It has good autumn vigour, getting the crop off well before the winter closes in, good pod shatter resistance and it also has good oil content of 44.6%.
