Far more similar to 2020 than 2019 in both cabbage stem flea beetle pressures and soil moisture levels in most parts of the country, this autumn is likely to reward late August and September sowing in much the same way it did last season.
Lower adult beetle populations following generally lower spring larval levels are being confirmed anecdotally by 2021 harvest reports, with nearly three quarters of growers providing csfb Smart feedback to NIAB reporting few, if any, beetles in trailers or stores.
At the same time, while being disruptive to combining, the early August rainfall again means plenty enough seedbed moisture for rapid establishment.
“The National Cabbage Stem Flea Beetle Management Study we ran with ADAS, NIAB and almost 200 growers responsible for 15,000 ha of OSR this past spring showed 85% of crops sown after August 21 being taken through to harvest,” explains Bayer campaign manager, Lizzie Carr-Archer.
“True, this was a little less than the 93% of crops sown up to August 20. But it was a vast improvement on the 55% of late August and early September sowings the previous season our 2020 study showed being taken to harvest. The fact that 80% of last season’s later-sown crops were reported to have suffered little or no CSFB challenge and 83% had good or reasonable soil moisture levels during establishment clearly made all the difference.
“This bodes well for 2021 planting. All the more so, with rapeseed market prospects remaining at such encouraging levels and little wheat and spring barley being combined before the second week of August.”
Results from the 2021 National CSFB Management Study also underline the particular value of using seedbed fertilisers and vigorous fast developing hybrids for later drilling. They were the only two of the 14 main autumn techniques being used by growers sowing in the later slots to score more than 6.5 for their effectiveness on the 1-9 scale.
“While DK Exstar with its all-round strength is the clear first choice for early drilling, its rapid develop in both autumn and spring make it equally suitable for sowing in late August and early September,” explains Dekalb technical specialist, Richard Williams. “TuYV-resistant, DK Excited and DK Exception are similarly flexible here; as is highest merit RL candidate, DK Extremus.
“The later planting gets, the more important are varieties with ultra-rapid autumn development to make the most of the lower temperatures and shorter days that put particular pressure on both leaf and root growth,” he adds.
“This is where DK Exsteel really comes into its own. Almost 90% of those with experience in growing the variety report it as noticeably better in its autumn development than other varieties. What’s more, it has consistently been recognised as one of the most vigorous autumn developers of all the 40-plus varieties trialled by Agrii each year.”
Alongside fast-developing hybrids and effective seedbed fertilisation, of course, the least possible tillage to retain moisture, well-firmed soil in the immediate vicinity of the seed for first class seed-to-soil contact and a consistently shallow sowing depth to ensure the most rapid and even crop emergence also become increasingly important with later drilling.
Of the 17 main techniques being employed to manage the cabbage stem flea beetle threat at establishment, four stood out as the most successful in the latest national CSFB management study run this spring by Bayer, ADAS and NIAB with a broad cross-section of UK growers.
Together, our market-leading Dekalb genetics and the Bayer 2021 Establishment Scheme provide you with the best OSR growing support in the business.