The wind of change is blowing through oilseed rape production
The wind of change is blowing through oilseed rape production and a perfect storm is approaching – one that is going to have to be tackled by farmers and plant breeders alike if OSR is to remain a key break crop, suggests one of Europe’s major plant breeders. Dominic Kilburn travelled to Germany to find out more.
In a world post-neonicotinoid seed treatments, of continued restrictions to crop protection products, of climate change threats and of increasing disease and pest resistance, things are going to have to change with oilseed rape.
German plant breeder DSV reckons that, since the ban on neonicotinoid seed treatments in 2014, most crops planted across Europe have been affected by additional losses from pests, and so the time is right to introduce ‘Smart breeding’ technology in the form of a ‘Post Neonic’ (PNN) concept.
DSV UK managing director Mike Mann (left) said that the company started looking even closer at OSR development following the ban of neonic seed treatments, with the realisation that the environment in which to grow the crop was changing. “The catalyst for our renewed focus on the OSR was certainly the ban,” commented Mr Mann during a visit to the company’s headquarters at Lippstadt, in the west of Germany. “And our reaction to the changing conditions required to grow the crop – the neonic ban and other threats – has been to change the overall breeding strategy,” he explained.
Mr Mann suggested that, until now, variety choice for UK growers has been based on gross output and yield, which breeders successfully delivered. “The RL has pushed variety maturity later to gain the extra in yield, but this is a problem as farmers want earlier maturity with OSR in order to make time for the following crop,” he said. “However, the RL is now looking at other issues and encouraging breeders to get better disease ratings, for example.
“If you take the top 10 yielding varieties on the RL, there is statistically no difference between them, but growers need to look at the whole package that a variety can offer – stem stiffness, vigour as well as disease resistance,” he added.
According to Mr Mann, the concept of DSV’s PNN varieties rests on four key requirements including rapid establishment and plant growth; optimum pod presentation; proven consistency and enhanced biomass and green area index control.
DSV’s Candidate variety Dariot, up for full recommendation this autumn, is the breeder’s first variety that demonstrates most of these key characteristics, he highlighted.
“The primary demand from growers is wanting the plant to grow quickly – yes, there can be an advantage to slower growing crops if they are planted very early, in late July, but most crops are planted mid-August onwards and need speed of growth.
“We recognise that the key thing is to get root structure going, rather than top growth, which is not so important. Ideally, we are looking for a compact plant on top and lots of root structure underneath,” he suggested.
“A key attribute of PNN is that it is planted and it grows quickly to 4-true leaves, but that it doesn’t go through the stem extension stage pre-winter. If it can grow quickly away from damage from flea beetle, it will also grow faster than phoma spores can travel down the stem, restricting the disease to just the leaf,” he added.
He explained that PNN varieties also have a reduced apical dominance compared with some varieties, whereby the main shoot of the plant doesn’t dominate and more energy and nutrients are put into the side branching than outright plant growth, increasing flower and pod production.
“This profile enables PNN varieties to produce the optimum number of pods for the plant, even in poor conditions,” added Mr Mann.
Yield stability, year-on-year, was another key aspect of the PNN profile, he continued. PNN varieties have real durability and resiliance at their core. Developed to deliver consistent performance in a wide range of growing conditions, they are also equipped to cope with the wider range of climatic conditions anticipated in the future, he said.
“RL data can be misleading – a variety can have a great performance in year 1 of trials and perform indifferently thereafter, but it remains on the List. Our variety Incentive, for example, has been on the list for three years and remains near the top because of its consistent performance each year.
“For Dariot, and following material, the stability is also there. It’s important that varieties perform well in different years and growers should always consider the Average LSD (least significant difference) score on the RL – it’s key,” he added.
Mr Mann said that PNN varieties are also characterised by their controlled biomass and high green area index early in the spring and summer growing cycle. This combination, he pointed out, allows maximum photosynthetic efficiency, often through a proliferation of a larger number of small leaves, without the risk of smaller plants becoming too bulky. “This key feature also provides PNN varieties like Dariot with improved nitrogen efficiency, enabling every unit of nitrogen applied to the crop to go into plant growth.
“We want a plant which has sufficient leaves to capture enough sunlight to develop a good tap root – controlled growth early on and with good canopy structure and controlled biomass,” he said.
According to DSV product manager OSR International, Dr Alexander Doering (left), problems with pest damage to oilseed rape are not limited to British crops.
He said that in Germany, over the past 10 years, there has been a clear shift in resistant pollen beetles and pyrethroid efficacy was now at just 10 per cent. “This is the same picture in most other European countries where pollen beetle is one of the most important threats to OSR,” he explained.
Dr Doering said that the restrictions put on pesticide use being seen across Europe were on-going, highlighting a recent change in regulation for the application of Biscaya (thiacloprid) for control of pollen beetle in Germany and Austria (albeit for this season only, believes manufacturer Bayer).
“We know of the significant losses from flea beetle experienced in the UK following the neonic ban and, in Germany, particularly in the north, there was huge damage from root fly in the 2014/15 season, although it was not so bad in 2015/2016.
“There were also problems with flea beetle but in Germany it’s not such a key problem as in the UK,” he added, pointing out that of 4.5mill ha (11mill acres) of OSR drilled in the EU in 2014/15, nearly all crops showed losses.
“With increasing restrictions on pesticide use, low numbers of new innovations coming to the market, more insect and disease resistance to current products and the impact of climate change, we know there needs to be new approaches to this crop and DSV wants to find solutions for oilseed rape growers in Europe.”
DSV is actively looking into new technology with which to apply to growing oilseed rape including companion cropping, continued Dr Doering.
The work is only one year old and suggested benefits include nitrogen fixing, weed suppression, soil improvement and pest repellent.
“Although the 20th August is a typical start date for planting OSR, we would recommend earlier drilling if companion crops such as clover and legumes are included so that they establish quickly and fix any available nitrogen as soon as possible,” he explained. “In the best case scenario, they also offer good weed suppression in the autumn and then die off in the winter reducing the need, and the cost, to spray them off.
“The mix of plants has to be right though otherwise they can create too much competition for OSR and risk stem elongation before winter,” he added.
Dr Doering suggested that the repelling effect of companion plants could reduce pest pressure in crops while their roots have a positive effect on soil structure.
“The positive economic benefit is expected to be about 100-150 euro/ha from the saving in crop inputs, but that does depend on whether you have to spray them off or not. There is the additional cost of the seed to bear in mind too.”
Other areas of work are focusing on drop-leg sprayer technology borrowed from the veg sector to apply pesticides below the level of the flowers and away from bees, to reduce negative impact of insecticide sprays. In addition, under-sowing of grass in OSR in the spring is being trialed to help conserve nitrogen by reducing nitrate loss through leaching in the autumn, holding it for the next crop, explained Dr Doering.
DSV employs more than 100 staff at its breeding and testing stations. There are two hybrid systems used in the breeding programmes – MSL and OGURA systems, according to OSR breeder Detlef Hauska.
Both hybrid systems are broadly similar, as they involve producing a pollen sterile mother line and a fertile pollinator (restorer) line. The aim is to have the sterile mother line and the fertile pollinator line derived from very different gene pools, and to genetically combine well to produce maximum benefits. The crossing of the mother line and the pollinator line, to produce the F1 Hybrid, ideally takes all the advantages of both lines, and links to higher seed and oil yields as well as to a better agricultural performance of hybrids in comparison to conventional lines, he said.