iOSR growers have unanimously highlighted the need for fast establishment next season to assure strong, consistent crops for the winter.
Flea beetle has driven Hertfordshire iOSR grower John Haynes to distraction in recent years. Significant areas of crop have been lost, even though he has employed extreme measures in an effort to contain the problem, including spraying at night when beetles are more active.
But with oilseed rape the most profitable crop on the farms he manages, Mr Haynes will persevere and in the coming season plans to refine establishment techniques across an increased OSR area of more than 330 hectares.
Mr Haynes says: “The beetle threat for this autumn remains. There’s evidence of the high beetle larvae legacy from last year’s infestation, as witnessed in the brittle, dead stems on significant plant numbers. Without the prospect of a seed treatment derogation, control will be reliant on multiple pyrethroid sprays.
“Last year it was clear the early-drilled crop established far better and withstood the effects of the flea beetle activity. Later-drilled fields were slower to emerge and got hit extremely hard; they remained far patchier all season and never caught up to any extent. Consequently, this year we plan to start drilling on August 8 and will run 24 hours a day if necessary to get completed as quickly as possible.”
WINTER barley has experienced a resurgence of interest among growers, largely thanks to the higher yielding, more competitive six-row winter barley Hyvido® targeting blackgrass reduction, but also as an early entry to get OSR away in autumn. However, with the earlier planting limiting staleseedbed options, and most iOSR growers using some form of min-till or strip-till to establish some or all of their crop, volunteer competition is now a greater threat.
James Southgate advises volunteer competition needs to be removed quickly with Fusilade Max to allow strong OSR seedlings establishment. In the early stages any shading will slow growth, and competition for nutrients and water can check autumn development.
He says: “Fusilade Max is extremely crop safe and won’t check development of OSR seedlings. It is also rain-fast, for effective use in catchy autumn conditions. It will quickly remove volunteer competition, but is also effective on grass-weeds including brome, which some farms have been reporting as an increasing issue.”
Mr Haynes, who is also looking to grow some hybrid OSR varieties for the first time this year to get a head start with vigour, is adamant encouraging a strong tap root and early root growth can help plants to recover from flea beetle attack.
He says: “We plan to put some early N into the top of the seedbed prior to drilling so it is readily available for the emerging seedlings. “We’ll also make sure we give plants sufficient N so as not to restrict autumn growth. We may lose some leaf growth to winter frosts, but if the crop has built a really good root structure, it stands it in good stead to make best use of nutrients and soil moisture through the rest of the season.”
Mr Haynes’ variety choices for the new season have focused on improved disease resistance.
“We really struggled to control light leaf spot [LLS} last spring, which undoubtedly had an impact on the performance of some varieties. Better resistance will give us greater flexibility in terms of application timing, especially if spray days are restricted, as well as product choice.”
This autumn, iOSR growers will be tasked with evaluating and feeding information into the new Syngenta Phoma Alert agronomy decision support service. Managed by ADAS, the initiative will monitor reference trial crops to identify disease development and, combined with weather forecast data, provide an early warning of spray thresholds for Plover application.
ADAS trials show phoma remains the key target for early treatments in autumn, and indicate the later threat of initial LLS infection is better countered in November or December.
Syngenta technical manager James Southgate says: “For applications in September to November, Plover alone will provide the most cost-effective phoma disease clean-up and protection. For follow-up treatments, or later one-spray applications, a more robust rate of Plover should be used, in conjunction with tebuconazole to bolster LLS control. It is important to start LLS control with a preventative application in winter, but the trials indicate where LLS is the main target, these applications are possibly best left until around Christmas or into the New Year to give protection when disease infection is likely to start.
Mr Southgate adds: “Resistant varieties can help delay disease spread and reinfection, allowing more time for treatment, but control of early spots remains crucial to protect yield.”
Populations of Myzus persicae have remained persistently high so far this season, increasing the potential risk of turnip yellows virus (TuYV) in OSR crops. Infection can result in red, yellow and/or purple leaf mottling and reduce plant viability in spring. Typically, TuYV reduces yields by 15% in UK crops, but the figure can exceed 30%, especially when aphids spread the virus in early autumn.
IN Cambridgeshire, Keyston Farms’ manager Joe Dillibero has designed his own adaptation to the farm’s Horsch Sprinter drill, with the addition of a new tine which will create more tilth under the seed to encourage faster rooting during the early growth stages. The aim is to achieve stronger early growth to get the crop away from pests, primarily flea beetle and slugs.
“Oilseed rape follows spring barley, for which the ground would have been ploughed, so the soil structure is generally good,” Mr Dillibero says. “However, while the initial growth was strong last year, the plants appeared to run out of steam in November. With a better root structure from improved establishment, and 30kg/ha of autumn N, I hope the crop will keep growing.”
His aim, this year, will be to drill OSR around August 15, which doesn’t leave much time after the spring barley harvest, but Mr Dillibero believes it is more important to get the crop well established, rather than wait and utilise a stale seedbed.
He says: “We are moving as little soil as possible with the drill tines operating straight into the barley stubble, so grass-weed establishment is minimised. Spring barley has worked really well for us in reducing blackgrass pressure in the rotation and it yields well.”
Mr Dillibero calculates creating better conditions for fast OSR establishment will enable seed rates to be trimmed back this season across the 166ha which the farm has allocated for oilseed rape. Conventional varieties will see seed rates at 70-75/sq.m, with hybrids typically at 45 seeds/sq.m. In an effort to further improve the consistency of plant stands, variable rate sowing, based on soil type maps, could see seed rates increased by 10- 11% on heavier soils.
The new drill configuration used this year will give row spacing at 25cm behind each Rooting for growth Joe Dill ibero tine, rather than band sowing, with seed covered by the following harrow and roll. The lower seed rate will allow 10- 15cm between plants in the row. “This year we have some big crops, but they never really branched or thickened as we would have liked. Giving them more space, and possibly looking at some spring PGR management, may help achieve higher yields year.”
Syngenta’s new field technical specialist for insecticides Dr Max Newbert points out infection is widespread in oilseed rape and weeds across the country.
“Earlier sown crops can be exposed to greater aphid pressure and activity for longer,” Dr Newbert explains. “The problem has been further exacerbated by pyrethroid insecticide resistance with Myzus and the lack of neonicotinoid seed treatments which offered control of early aphid infestations. Growers need to be actively checking aphid numbers in recently emerged crops, or at least taking note of national monitoring results on the Syngenta website.
“Trials have shown early treatment with Plenum, at the initial signs of infestation and before aphid populations build up, can give the best levels of virus reduction. There is no known resistance to Plenum and it will give about two week’s control in the growing crop, by which time aphid numbers should start to decline into the winter.”