Controlling the damaging disease of Sclerotinia in oilseed rape will be more important then ever this season as oilseed rape prices hit some of the highest prices seen for several years, is the advice from Ruth Stanley, country manager for off-patent manufacturers Life Scientific.

Sclerotinia stem rot is usually the main disease to consider during the flowering stages of oilseed rape.

“As prices sit at circa £800/tonne at the end of April, it’s  vital to protect that all crucial yield potential as crops come into the flowering stage,” she says.

“Although there is a wide variation in growth stages of oilseed rape crops across the country, mostly due to CSFB or pigeon grazing, the flowering period is already underway in many earlier drilled crops and this is coinciding with conditions suitable to the spread of sclerotinia in some areas.”

“With sclerotinia it’s all about protection, and this means getting the timing of that first spray right, and that’s one of the biggest difficulties that growers have,” she says.

“Fungicides need to be in place before significant petal fall occurs in the oilseed rape crops, as the ascospores released when the sclerotia germinate need a nutrient source, which comes from the petals.”

“So if the petals attach themselves to the leaves or stem of the plant as they fall and airborne inoculum is around, there is an opportunity for infection to take place.”

Although the infection cycle of sclerotinia sclerotiorum is complex, a good understanding of the three main risk factors – the presence of sclerotinia inoculum, warm and humid weather conditions and crops in flower – will help to target control.

“Germination takes place when soils reach a temperature of 8-10C with some soil moisture. The spores then infect plants when temperatures are above 7C and there’s high humidity.”

The AHDB Sclerotinia map is the best source of information on current rusk and can be found on the AHDB  cereals and oilseeds website  https://ahdb.org.uk/sclerotinia-infection-risk-alerts-for-oilseed-rape

The map shows the potential infection risk level at oilseed rape monitoring sites across the UK and is based on a simple traffic light system of high, moderate and low risk and individual site risk can be accessed by clicking on the map.

Mrs Stanley notes that whilst timing is all important for the best control, when deciding on product choice for sclerotinia it is important to consider using a non-triazole option, as part of an anti resistance strategy, particularly where a triazole has already been used in the programme, perhaps for Light Leaf Spot control.

She recommends a non triazole based option such as Azoxystar as a good alternative.

“As a strobilurin, Azoxystar also has strong physiological effects on the crop such as reducing the production of the stress hormone ethylene, which causes early stomatal closure, reduced green leaf area, pod abortion and pod shatter.“

She notes that in an extended flowering season or if crops are at various growth stages due to pigeon damage, for example, two applications can be used as any fungicide used will only give around 3 weeks of plant protection and it can be difficult to get the application timing to fit perfectly with weather and growth stage.

“There’s about a three-week limit on spray persistency. So getting applications to cover the whole petal fall period is more likely with a two-spray programme. And we’ve learned from past experience that sclerotinia doesn’t go away if it dries up – dew is enough to cause petal stick,” she says.

For more information on Azoxystar including product label, safety data sheet and compatible tank mixes see the Life Scientific website AZOXYSTAR^® – Life Scientific International or download the app

Continued innovation and a commitment to deliver cost-effective products to IE growers despite the challenges Covid-19, sees Life Scientific launching its first plant growth regulator (PGR), LS Trinex, this spring.

 LS Trinex contains 250g/l trinexapac ethyl and is a PGR registered for use on all varieties of winter and spring wheat, barley, oats, rye, triticale and ryegrass seed crops

Manufactured by off-patent manufacturers Life Scientific, LS Trinex is a reverse engineered formulation of its reference product Moddus.

Life Scientific is able to offer off-patent products to agronomists and growers faster based on the company’s unique scientific concept to reverse engineer a product from the original to produce a product accepted as the same by the regulatory authority.

“LS Trinex is a cost-effective crop management tool which protects and enhances yield potential, and comes to market at a time when growers are under pressure to scrutinise input costs whilst not compromising yields.” says Ruth Stanley, UK and IE country manager for Life Scientific.

“PGR’s will be an essential part of the spray programme this spring; we had a kind autumn, crops went in well and so far, the winter has been kind, so crops are coming into the spring growth period looking lush, forward and full of potential. “

“It is important this potential is managed correctly, which means ensuring lush crops are prevented from lodging.”

There are three key factors that impact lodging risk, she points out.

“Size of the canopy in the spring is a critical indicator of crop development and lodging risk. This can be measured by its green area index (GAI).”

“The best way to achieve a stable high yielding crop potential, in the lusher forward crops is to establish a good base. Like good building design, foundations are key to a stable structure, so early PGR’s and a continued programme of PGR’s will give the best chance to maintain a standing crop through the season.”

“Remember a higher yielding crop will produce heavier ears. Heavy ears put weight on the stem so the higher the yield potential the greater the risk. Estimates are for every extra tonne over 9t/ha, lodging resistance Is reduced by 0.5 points,” she says.

“Varieties also have different resistances to lodging; this comes down to differences in height, tillering capacity, stem strength and speed of establishment. Varieties with a score of 7 or less on the AHDB Recommended List should be considered at risk of lodging and should be managed carefully.”

How does LS Trinex work?

• Plants need to be actively growing to metabolise LS Trinex.
• As a contact acting PGR, LS Trinex, inhibits the production of gibberellic acid and shortens the internodes, reducing lodging on cereals and grasses, and has a wide application window, from growth stage 30-39 (in winter cereals).
• When used at GS30, LS Trinex helps root development and increase root plate diameter. This prevents lodging and also increases the plants ability to absorb water and nutrients from the soil.
• Early use will also hold back and thicken the main stem, encouraging side tillers and even up the crop. By temporarily reducing the rate of stem extension with a PGR, such as LS Trinex, it means more of the plant resources can be diverted to thickening the stems and promoting root growth.

LS Trinex joins a list of products that have recently been brought to market from Life Scientific such as the first off-patent prothioconazole and tebuconazole mixture Oraso and prothioconazole fungicide Aurelia.

For more information on LS Trinex or any other products in the Life Scientific portfolio please visit the Life Scientific website https://lifescientific.com/products/

Feb 2022