With breeders better understanding the requirements of the UK market, sift through the Recommended List data and look beyond variety gross output
With breeders better understanding the requirements of the UK market, sift through the Recommended List data and look beyond variety gross output. That’s the message from one plant breeding company as growers consider their oilseed rape planting options for later this year. Dominic Kilburn writes.
Bayer’s seeds product manager, Sarah Middleton said that developments in breeding such as phoma and light leaf spot resistance, or lodging scores, have become more of a priority among breeders and she urged farmers to make better use of RL data before making their variety choice in 2016. “Disease scores, for example, are capturing the imagination and we are trying to encourage growers to prioritise the ‘agronomic merit’ of each variety by understanding the Recommended List better – in combination with varietal yield consistency over a number of seasons.
“Simply selecting a variety with the highest RL gross output may be a high risk strategy,” she added.
Mrs Middleton explained that the agronomic merit rating is a measure of a variety’s inherent resilience – including lodging, stem stiffness and resistance to disease – and the risk that the variety poses in adverse conditions.
She highlighted that when considering the agronomic merit table for the 2016/17 Recommended List (East/West), then Bayer’s InVigor hybrid variety Harper topped the table, with stable-mate Fencer in fourth place – both varieties having a low variance in yield consistency (1.3 and 0.6 respectively) over the past three years.
“Our varieties have good disease resistance and oil content, and good autumn vigour, and we can add high levels of light leaf spot resistance too,” she pointed out.
She suggested that Bayer’s latest hybrid variety InVigor 1030, currently a Candidate in RL trials, will be the earliest maturing variety on the List should it become fully recommended this autumn. “InVigor 1030 is very competitive in all regions but with a gross output of 109 per cent in the North it is a particularly good fit for Scottish growers, as well as those in the north of England,” she said.
High seed yields (107 per cent in the North, 100 E&W) plus high oil contents (46.2 and 46.8) will make the oil bonus very attractive, she added.
InVigor1030 also comes with a 9 and 7 rating for phoma and LLS – the variety with the best combination of the two diseases (plus lodging resistance), states Bayer. “We’ve noticed that southern growers are becoming more aware of light leaf spot and the choice of varieties seems to be prioritised towards those with more resistance to the disease compared with phoma.
“Our message to growers however is that they need a good balance of resistance between the two.”
While Frontier has exclusivity over seed sales of InVigor1030 this season, Bayer’s National Listed hybrid variety InV1020 will be sold through the remainder of the trade. Seed is available for both varieties for this autumn’s drillings, Mrs Middleton pointed out.
She said that InVigor1020 is a similar variety to InV1030 in that it also comes with high ratings for both phoma (8) and LLS (6) and both varieties have good autumn vigour.
“With good autumn vigour, medium to early maturity and good stem stiffness, InVigor 1020 takes the best attributes of Harper and Fencer, as well as having one of the highest oil content of any variety currently available (46.5 per cent).
“It’s a stable variety which will provide growers with a good chance of an oil bonus and, while InVigor 1020 is suitable for all regions, it is slightly more competitive in the E&W,” Mrs Middleton added.
Bayer’s trials site at Thorney, near Peterborough in Cambridgeshire, demonstrated visual small plot comparisons of oilseed rape establishment when considering various seed treatments, replicated pigeon damage and later sowing dates; across hybrid and conventional OP varieties.
There appeared to be little difference in crop development between the un-mown (left) and mown plots of hybrid variety Harper.
All plots were drilled on the 28th August 2015 and, as a low pressure site in terms of cabbage stem flea beetle and disease, little difference was seen in establishment when comparing untreated Harper drilled at 15 seeds/m with seed treatment Modesto (clothianidin + beta-cyfluthrin) and HY-PRO Duet-applied plots.
However, when drilled at 50 seeds/m there was a clear difference in establishment between the treated and untreated plots. Bayer’s latest broad-spectrum experimental seed treatment, which the company is hoping for registration in time for the 2017 crop, was also compared and visually performed similarly to HY-PRO Duet.
“Although pressure from adult CSFB on this site has been low, we have seen huge differences in emergence in untreated and treated crops on other trial sites we operate,” continued Mrs Middleton. “One in particular, near Royston, the untreated trial plot was completely lost to flea beetle where pressure was very high.
“Very early establishment is the only way to avoid major damage in that situation and protection from disease at that stage is vital,” she said.
“Generally, growers are trying for the middle of August as optimum drilling date to get the crop up and away early, but of course a lack of moisture at that time can be a worry. “Seeding too early and at high seed rates can also be a problem come the spring.”
She suggested that sowing rates of 25-40 seeds/m were typical for hybrids, depending on seedbed conditions and pest threat, aiming to get 30-35 plants/m established.
Replicating pigeon damage to hybrids and conventional varieties, plots were mown (strimmed) to ground level at the site in late January (at GS19-20) this year and then visually compared again in April.
“In the last few seasons we’ve noticed that hybrids have better resilience to pigeon damage and are able to grow back better, and so it was interesting to make direct comparisons between hybrid and OP recovery.
“The key point at this site is that there is little difference in crop development between the un-mown and mown plots of hybrids Harper and Fencer. Both varieties have good spring vigour and so damage such as this doesn’t seem to be a problem in their subsequent development.
“But when you compare OP varieties in the same trial, they don’t have the same powers of recovery and won’t make a crop following that level of damage. Farmers will want to cut costs through the use of farm-saved seed, or cheaper OP seed, but it comes with a risk. The extra cost of a hybrid seed is an insurance policy and they show their benefit when conditions are tough,” explained Mrs Middleton.
“Growers are aware of hybrid vigour in the autumn but not so much in the spring and, across our European breeding programme, we see good recovery from our hybrids,” she added.
Bayer also demonstrated the effect of a late sowing date (23rd September) on its five hybrid varieties currently on the Recommended List or in RL trials, in addition to OP variety DK Cabernet. “We know that hybrids tolerate a later sowing date compared with OPs and our hybrids have shown this here, all establishing similarly in this late sown slot, although crops are a little further behind those sown in late August, as you might expect.
“Being sown late can mean there is less disease in the crops and this appears particularly true of Fencer which is a very good variety in late sown situations.
“It hangs on to its yield and oil better than other varieties when sown late,” she highlighted.
“Sowing later with hybrids might be a tool to escape adult beetle attack in a high pressure location or used if growers are delayed by a wet cereal harvest. It could also provide the opportunity to produce a stale seedbed for black-grass control pre-drilling,” concluded Mrs Middleton.
The NFU is making another submission for Modesto and Cruiser neonicotinoid seed treatments for an emergency use authorisation for sowing winter OSR in 2016, says Bayer’s Sarah Middleton. The nature of an Emergency use Approval meant that any use must be restricted to those areas of greatest need, she explained, and any conditions of approval were not clear at this stage.