New oilseed rape genetics being developed by DSV are building on traditional pod shatter characteristics to increase harvest security in light of increasingly variable growing conditions now experienced across Europe.
DSV's latest RL addition DSV Dolphin is the first of a new generation of hybrid OSR varieties combining a key set of genetic traits developed to protect them against adverse weather conditions later in the season, says DSV's Sarah Hawthorne.
"Pod shatter resistance has become an increasingly sought after trait for oilseed rape growers faced with increasingly challenging growing conditions and the need to maximise efficiency of production," she explains.
"Of the 31 varieties on the current RL, 19 are identified by breeders as having pod shatter resistance including the DSV varieties Matrix CL, Beatrix CL and Miraculix CL with our other popular varieties DSV Duke and Duplo also sharing the gene.
"For several years, many growers have thought of pod shatter as an absolute with varieties either have resistance to it or not.
"But latest thinking is that varieties have degrees of pod shatter resistance with organisations such as the John Innes Institute suggesting many factors are at play in both the physiology of plants and how they react to external conditions.
"In particular, temperature at both vernalisation of the seed and in the later stages of the plant's development can have a profound effect on whether seed is lost regardless of whether varieties have pod shatter genes or not."
Creating the right balance
According to DSV UK managing director Dr. Alex Doering, loss of seeds from pods to the surrounding environment is a natural behaviour of many plant species.
"But if this opening occurs to easily, seeds can easily be lost during harvest time leading to poor yields and increased volunteer pressure in the following crop," he points out.
"While high pod shatter resistance may reduce the losses before and at harvest, it can also increase the losses at harvest substantially because the pods cannot be sufficiently threshed by the combine and seeds will remain within the pod.
"So, it is important to create a balance between pod opening for an easy harvest and the necessary pod shattering resistance, so not too much seed gets lost at harvest time.
"Many factors affect how and when an oilseed rape pod shatters, including prevalence of stem diseases such as verticillium wilt, external weather conditions, the physical strength of pods, the evenness of them and mechanical damage through the growing season."
Three key features
Sarah Hawthorne says current DSV varieties address many of these potential impacts with features such as high tolerance to verticillium wilt, comprehensive phoma stem canker resistance and tolerance to sclerotinia.
"'All 'Powerful Pods' varieties add three core characteristics to these. These are greater flexibility of the pod structure, improved function of the pod valves and greater space around individual seeds.
"Increased flexibility, for example, gives pods a resilient 'rattle-proof' structure which makes them less friable and more able to absorb energy rather than break open in conditions with extremely high winds or hailstorms.
"This enhanced flexibility also allows pods to cope better with the uneven tensions produced from drying after rainfall, which can lead to seed pods splitting.
"Varieties with 'Powerful Pods' also have a stronger valve margin - the mechanism at the base of the pod which effectively controls the opening of the valves, effectively the sides of the pod containing the seeds.
"This avoids early triggering of the opening process particularly when pods are stressed such as in adverse weather or when going through the combine header.
"More space in individual pods allows seeds to develop fully as they mature so a variety can reach its full yield potential, but it also stops growth stressing the pod which can again lead to premature failure."
Results from DSV's own trials and an AHDB analysis of pod shatter results have underlined DSV Dolphin's performance in respect of harvest performance, Sarah Hawthorne adds
"In random impact tests (RIT) carried out at the DSV breeding station at Thule in Germany where pods from different varieties are bombarded with steel ball bearings in controlled conditions, DSV Dolphin achieved one of the best scores for seed retention.
"AHDB Results from an AHDB in 2023 analysis have also shown little difference in the performance of DSV Dolphin with regard to seed loss compared to many of the most popular pod shatter varieties."
DSV Dolphin in detail
DSV Dolphin's fully featured agronomic package works alongside the 'Powerful Pods' feature to produce a truly resilient variety for modern production, Sarah Hawthorne adds.
"DSV Dolphin is recommended for the East/West region on the current RL with a gross output of 106%, the joint highest on the list, and this supported by some stand-out features including a 46.6% oil content.
"With TuYV resistance and scores of 7 for stem canker, 8 for lodging and a 9 for stem stiffness, DSV Dolphin is a simple to grow OSR well suited to the current economic and environmental climate. It also has a 7 for flowering and a 4 for maturity.
"It also has strong tolerance to Verticillium Wilt as well as having some of the best tolerance to Sclerotinia in DSV’s portfolio, with early senescence from either these conditions known to cause excessive seed loss before or at harvest.
"DSV Dolphin also offers growers a high level of protection from the growing threat of the TuYV virus now endemic across the UK where it has the potential to reduce yields by up to 20%.
"It is also one of only a few varieties to feature RLM7+ and multi-gene resistance to stem canker and is an agronomist-friendly variety well suited to integrated crop management systems due to its high resistance to light leaf spot with a score of 6."