Farmerswithout black-grass have heard enough stories by now to know it wont be awelcome addition to their rotation plans, nor would those with susceptibleblack-grass want a resistant strain adding to their problems.
So,as combines roll across the country, its worth paying attention to theblack-grass population map released by the National Farm Research Unit; itsturned a few heads.
Themap, showing population levels by postcode, identifies a clear route travellingnorth via the A1 from the Midlands into Scotland, suggesting the problem weedis hitchhiking up motorways into new territories.
The map shows the needfor machinery operators to pay special attention when moving from field tofield, says CharlieBaker, chairman of the National Association of Agricultural Contractors (NAAC)Agricultural Operations section, especially when moving from farms with knownblack-grass problems to unaffected fields.
Hesays members of the NAAC abide by a shared understanding and acknowledgement ofthe golden rule, as set out in the NAAC Assured-Land based Contractor Scheme(ALBC): Persons entering or leaving a premisesshould ensure their footwear, clothing and machinery are clean when they enterand again when they leave. Contractors should make use of any facilitiesprovided on-farm and must follow up-to-date Defra guidance on bio-security; thecontractor must follow the farms/customers biosecurity policy if it is morestringent than Defras biosecurity policy.
Wemust ensure kit is kept in the cleanest possible condition, especially whenmoving between farms. Its easier now with modern machines theyve beendesigned to stop the build-up of material and chaff. Although primarily forfire prevention, it has the secondary effect of preventing the spread ofunwanted seed.
But farmers and contractors can do more to prevent seed spread byclearing stone trays and combine headers with air hoses or pressure washerswhen moving locations.
According to Phillippa Overson, Bayer CropScience, even a fewestablished plants in your gateway can lead to a much bigger problem if leftuntreated.
A single black-grass plant is capable of producing up to and beyond 20tillers, and with each seed-head producing 100 seeds, you could find yourselfwith a big problem in a short space of time.
Checking gateways and field entrances at regular intervals whenmachinery has been into your fields will give you a good indication ifblack-grass is present and germinating.
Half an hour or so spent checking gateways in the weeks post-harvestcan save a lot of time, effort and money later on in the year when yourelooking at a much greater population and planning a much larger weed controlprogramme. The key indicators when identifying infant black-grass are; smoothfine leaves, a twisted leaf blade with a blunt tip and a purple tinge on thesheath of the plant.
Giveblack-grass a yard and it will take a mile, so get on top of it at the earliestopportunity and reap the benefits for many harvests to come.