25 April 2015 | Online since 2003



20 May 2014|Arable,Cereal,Crops,News

Yellow rust threat remains 'extremely high'


With the unsettled weather of late disease pressure from Septoria tritici and yellow rust remains extremely high, and spray intervals and dose rates will need to be closely monitored heading toward the impending flag leaf spray warns Bill Clark of NIAB TAG.

“Whilst normally septoria would be more of an issue in the north and west, and rust in the east, this year we are seeing high levels of yellow rust across most areas,” he says.

“However in the east where the rust is particularly aggressive, keeping on top of it is as important as getting on top of the septoria; Warrior races are rampant where no T0 was applied and will be moving up the crop quicker than sprays can control.”

“There are very few issues with mildew, so it really is a two horse race with a real focus on septoria and rusts for the T2 spray “he says.

Crops are at different stages of flag leaf emergence from just emerging to fully emerged with boots splitting, and it will be managing the interval between the T1 and T2 that will be critical. “Timing is all about how long leaf 2 has been out – if more than 10 days then the flag leaf spray has to go on – even if not all the flag leaves are out as it will be necessary to go on again as soon as the ears are out.”

However Mr Clark is keen to point out that dose rate of fungicides at T2 will be equally important. “Consider the rate of the SDHI first as that will determine the rate of control. Triazoles are of course important and in high risk situations - the days of using half doses are long gone - high risk crops need three quarters of a dose of a good triazole.”

Bill Barr, independent agronomist with Prime Agriculture based in Bedford, has recommended fairly robust fungicide programmes so far this season with tight intervals, and these are working well. “The top three leaves are clean, with any signs of yellow rust or septoria confined to the tip of leaf 4 and below. Any spray misses are very obvious!

“The key thing at the moment is keeping the interval between T1 and T2 to three or three and a half weeks – this is really important. If you get to over three weeks, then I would agree with Mr Clark and advise getting the T2 on even if the flag leaf is not fully emerged.”

“SDHI at T2 is essential and don’t skimp on the rate. If weather conditions mean that spraying is delayed until nearer four weeks, then it may be necessary to add in more triazole for a bit more eradicant activity.”

Mr Barr suggests that if the flag leaf is only half emerged, there may be a benefit of adding chlorothalonil to the SDHI if it is Adexar, but not to Aviator. “Then if rust is re-appearing and the planned flag leaf fungicide is Aviator, add in a strobilurin such as Comet 200.”

Steve Dennis of BASF adds that the kick back activity of Adexar will prove to be really useful where timings are delayed as we move towards the flag leaf spray.” You get much more curativity, more longevity of activity and better disease control with Adexar than we ever had with epoxiconazole.”

Mr Dennis suggests that where possible adding 1l/ha CTL to Adexar offering not only a more robust treatment but as a means of resistance management.

“It’s also worth noting that whilst Adexar is at the top of its game for yellow rust and septoria, it also provides good control of brown rust that could creep in towards the end of the season, and if disease levels are expected to be high, adding in some Comet 200 at T2 will bring additional benefits.”

Download




Comments


No comments posted yet. Be the first to post a comment

To post comment without approval login or register

Display name

Please enter your name

Email (optional)
Comment

Please enter your comment

Post Comment

Your comment submitted successfully.Please wait for admin approval.

Some error on your process.Please try one more time.



Jobs


17 April 2015
Technical Instructor, Agriculture & Machinery
Technical Instructor, Agriculture & Machinery. Agriculture, machinery, landbased, farming, engineering, groundskeeping, t...

13 April 2015
Agri-Retail Adviser
An understanding of Farm Assurance schemes and / or organic farming practices would be desirable. A background in the food su...

11 April 2015
Senior IT Support Engineer - DV Cleared
Experience administering virtualised server farms - VMWare, Microsoft System Center. IT Support Engineer - Permanent - West L...

24 April 2015
Property Manager
Part time assistant required to assist and undertake all aspects of property management, including; Rent reviews and lease re...

17 April 2015
Market Manager - Agriculture / Horticulture - Chemical Distribution
The role requires sales experience / technical knowledge of the UK Agriculture / Horticulture Industry. They are now seeking ...



Top stories you may have missed
10 April 2015 | Agri Safety

The permanent eradication of Bovine Viral Diarrhoea [BVD] in Scottish cattl...


10 April 2015 | Dairy

The abolition of milk quotas in Europe on 1st April has resulted in a numbe...


10 April 2015 | Cattle

The top 14 milk producing countries in Europe will increase their productio...


10 April 2015 | News

Matt Ware is the NFU's head of government and parliamentary affairs, based ...


10 April 2015 | Arable

There is a 'desperate need' to improve farmgate returns given low incomes a...


9 April 2015 | Arable

Rapid stem extension, after a slow start to spring, is likely to create spl...


9 April 2015 | Finance

The time has come for landlords to expect to see reductions in farm rents, ...


8 April 2015 | Cattle

Cogent’s reputation as a source of the highest calibre sires has been enhan...


8 April 2015 | Arable

The spread of exotic and aggressive strains of a plant fungus is presenting...


7 April 2015 | Animal Health

The FSA’s new Food Crime Unit wants the industry to share information, some...