As the 2018 iOSR series gets underway, the Syngenta grower group reports this year’s OSR crops have, for the most part, established well in favourable growing conditions.
Although vigorous leaf growth is likely to drop back in any hard frosts over winter, good root structures have been put down which can be expected to power early spring growth. That means growers could be looking at early spring fertiliser requirements, so as not to hold back the initial growth, advocated Syngenta technical manager James Southgate.
“The strong autumn foliar growth will have used up a lot of the residual nitrogen, and although the Green Area Index [GAI] may go backwards in February, any nutrients in shed leaves won’t have been recycled to support early growth.”
However, while crops need some early nutrition, growers should be mindful of applying too much N in initial applications. “The aim is to set the crop up for an optimum GAI of 3.5 as they come into flower,” he advised.
“There will be a tendency for this early growth to surge through growth stages. That can be effectively managed with spring PGR applications – to hold back stem extension and develop side branches for a strong and efficient crop canopy.”
The new iOSR Focus Site will provide growers and agronomists with an insight into innovative integrated crop management ideas and techniques – demonstrated in a real field situation which can be readily applied on farms.
The iOSR Focus Site, based at the Rougham Syngenta Innovation Centre in Suffolk, will assess new options at all stages of crop growth, from establishment techniques to seed rates; varieties; canopy management; nutrition and pest and disease control right through the season. Many of the ideas being trialled have been in direct response to concerns and challenges raised by the Syngenta iOSR grower group, as well as building on some of their pioneering experiences and reported successes.
“The challenges of growing OSR, and agronomy techniques have changed significantly over the past five years. The iOSR Focus Site will specifically seek to provide solutions for growers and agronomists to consider throughout the crops’ management,” highlighted Syngenta iOSR lead, Kat Allen.
Strong autumn root growth and healthy plants have given the opportunity to try a new cultural technique to break the cabbage stem flea beetle (CSFB) life cycle and potentially reduce pest pressure for autumn.
In November some plots on the iOSR Focus Site were mechanically chopped back to remove leaf stems and petioles containing the CSFB larvae; other plots will be cut back later in the season, before spring growth. Crops will be assessed for the effects on the numbers of beetles and impacts on yield.
The technique would appear to favour varieties which are more prostrate in autumn and winter growth, where the growing tip is safely protected while the leaves are cut back. “There will also be an effect from the spring vigour of some varieties, for both the timing of any treatment and the speed of recovery. The key will be if we can get crops to the desired GAI of 3.5 at flowering.”
Wet and mild weather over early autumn was positive for crop establishment, but did raise the spectre of early phoma infection and the risk of rapid development in small plants.
Tracking of disease breaking out by ADAS for the Phoma Alert website highlighted leaf spotting breaking out in the western counties in early October, then moving north and east as the month progressed. Under intense pressure varietal susceptibility brought a few days grace, but infection soon spread across all sites and crops.
However, forewarned of attacks, most growers were ready with phomaspecific treatments and did make timely applications to protect against spots developing. Furthermore, while there was talk of early light leaf spot (LLS) infection, the disease had not appeared to have developed to any great extent into December.
Even collecting and incubating leaves in conditions conducive to LLS had failed to identify any great infection. In recent years, ADAS trials and Syngenta research has shown that damaging LLS infection has typically not arrived until post-Christmas and into the New Year.
That has been good news for growers seeking to hold down autumn input costs, enabling them to focus primarily on phoma with Plover (difenoconazole) treatments in autumn, and possibly adding a cost-effective tebuconazole with later applications in higher risk LLS areas. Sustainable cropping A new Syngenta sustainable farming research initiative, designed to look at whole farm productivity and impacts through a five-year rotation, has already seen the effects of drilling techniques on oilseed rape establishment.
The first project site, on five commercial fields at the Allerton Trust’s farm at Loddington, Leicestershire, is researching effects of establishment through ploughing; non-inversion tillage and direct drilling. OSR emergence behind the plough was slow and extremely patchy, with the economic viability of the crop in question – possibly as a result of soils drying out. With non-inversion tillage and direct drilling, establishment was faster and more even where moisture was retained, with notable improvements in soils structure.
The iOSR farmer group will be visiting Loddington in February, with the opportunity to review the trials and look in greater depth at soil quality and enhancement with oilseed rape.
Congratulations to Wiltshire OSR supremo Martin Smart, who topped the Yield Enhancement Network competition for both overall yield and highest percentage of potential yield, with his crop of SY Harnas grown,near Trowbridge.
Look out for the next iOSR pages in Arable Farming for Mr Smart’s top tips and his ideas for this season’s crop.