Article taken from South East Farmer, May 2017.
Efforts to tackle blackgrass have produced some ""spectacular"" results on a trial site at Somerfield Court, Sellindge, just to the east of Ashford.
Farmers and others with an interest in tackling the pervasive weed were again taken on a guided tour of the site, home to a comprehensive range of trials being run by Agrovista South East.
The aim was to look at what was happening in the fields a few months after two earlier visits by interested groups just before Christmas, when several of the approaches looked to be showing promising results.
South East technical support manager Rob Purvis again led the tour of the trial fields, farmed by R Price and Sons and led discussion on the impact of the various treatments.
The first field of winter wheat, home to a blackgrass herbicide trial featuring 63 different combinations of stacked pre-, peri- and post emergence residuals and post-emergence contact chemistry, showed good results.
""Unfortunately the levels of blackgrass were not as high as expected, but we hope to see some differences between plots in July when the blackgrass heads are above the wheat," Rob said later. ""Gene rally, the stacking of pre- and peri-emergence chemistry has worked well and we have seen some positive results from the addition of Xerton (ethofumesate) to follow up residual treatments.""
The second trial is looking at whether hybrid barley is better at competing with blackgrass than conventional varieties, with the field drilled with strips of the hybrid variety Volume at 250 seeds per metre squared and the conventional variety Glacier at 350 seeds per metre squared.
The tour showed that although there was little difference in the numbers of blackgrass plants in the different plots, Volume seemed to be showing its spring vigour. ""Early indications are that it is competing well, despite it being drilled at a lower seed rate," said Rob. ""Blackgrass ear counts later in the season will prove interesting.""
Centurion Max was applied at the three- leaf stage of blackgrass, together with a water conditioner to buffer pH, in the third field, which was drilled with Clearfield rape variety Veritas and a companion crop of berseem clover.
""The Clearfield rape looks fantastic and the control of the difficult broad-leaved weeds, charlock, shepherds purse and hedge mustard, has been outstanding," said Rob. ""It has also been interesting to see how many non-Clearfield volunteer rape plants were among the stand, some of them spring rape from more than 10 years
ago, that have been taken out by an application of Cleravo and Dash.
""On the last tour it was clear that the Centurion Max had done a fair job of suppressing blackgrass numbers but had still left a large number behind. A December application of Astrokerb was applied, and with most of the blackgrass being shallow rooted, the final results were spectacular.""
The fourth field at Somerfield Court was autumn drilled with a cover crop of black oat and vetch that was sprayed off with glyphosate in early November with the intention of drilling Belepi wheat in late November /December, but unsuitable weather I delayed that plan until the spring.
Rob said: ""Further germinations of blackgrass : were sprayed off again in the spring and Belepi wheat was drilled at 350 seeds per metre squared I with a Vaderstad Rapid with cultivating discs raised so as to cause as little soil disturbance as possible.
""An area of the field was also drilled with the cultivating discs in place to provide a comparison. Because the cover crop was destroyed early, the soil was not bound together as well by the cover I crop roots, and this has led to a fair amount of soil disturbance.""
An autumn drilled cover crop of black oat and vetch in field five was sprayed off early spring, with I one area again drilled with Belepi wheat with a Vaderstad Rapid with the cultivating discs out of work and another area drilled with a Weaving GD drill.
""The Weaving drill has an angled drilling disc I with a following press wheel, and with more of the cover crop being intact at the time of drilling, the soil disturbance with both drilling techniques was reduced," Rob said. ""Early indications look to be positive as far as blackgrass numbers are concerned.""