Auto Trader Ltd
Farminguk
29 September 2016 | Online since 2003
Scrutton Bland


17 June 2010 15:40:26 |Arable,Produce,News

Potato growers urged to treat blight and Alternaria separately


Potato growers are being warned not to compromise blight control programmes during high risk conditions when tackling the threat of Alternaria. "During the current high blight risk periods, growers need to be maintaining the best possible control with Revus-based programmes, and addressing the threat of Alternaria as a separate issue," advises Glenn Wilkinson of Syngenta.
Olympus is the only fungicide with a Specific Off-Label Approval for Alternaria control.
Mr Wilkinson high lights the potential risk of using less effective blight fungicide’s that also claim some activity on Alternaria. "Independent UK trials by Eurofins and Agrisearch have shown that mancozeb-based fungicides were significantly weaker in controlling blight, compared to Revus. Compromising blight control at the crucial time of rapid canopy development would be entirely counterproductive."

Norfolk agronomist Simon Alexander believes blight products containing mancozeb at less than the current full rate of 1500g ai per hectare have limited effect on Alternaria. He reports one grower used fungicides containing mancozeb in every application on a field of Markies over the Alternaria risk period in 2008, but the crop was still severely hit by the disease. "Using straight mancozeb, to apply sufficient ai for any possible effect on Alternaria, could compromise blight control," he adds.
"In the past we have seen Alternaria coming into the crop late in the season, typically as it is beginning to senesce and hitting older lower leaves," he says. "More recently infection has occurred far earlier in the season and affected larger patches of the crop. It can quickly spread across the whole field and lead to early leaf loss." Attacks can lead to yield loss, smaller tubers, variable dry matter and potential skin damage that reduces marketability.

Disease risk forecast
Alternaria infection typically occurs after periods of dry weather initiate spore release, followed by humid conditions leading to infection. Crops under water or nutrient stress are typically more susceptible. Markies has proven the most susceptible variety, but infection has also been identified on other varieties, including Hermes, Saturna and Maris Piper.
This season Syngenta is piloting a new AlternariaCAST forecasting system with a group of growers and agronomists in the eastern counties and Shropshire, where the most severe disease attacks have been recorded. Mr Wilkinson added: "For the optimum Alternaria control treatment should take place before the typical leaf spotting signs of infection are visible. The aim is that AlternariaCAST will give a reliable forecast of conditions conducive to disease, and enable growers to time applications more effectively."
Building on the success of Syngenta’s web-based BlightCAST, the AlternariaCAST service will be evaluated during the 2010 season, with the intention to make it freely available to growers for following years.
Growers using Olympus in potatoes do so at their own risk and should be in possession of a SOLA certificate before application, which can be downloaded from the Chemicals Regulation Directorate (formerly PSD) website: https://secure.pesticides.gov.uk/offlabels/search.asp

Download

0 Comment

loginuserlogo
Name

Please enter your name


Email

Please enter your email

Please enter valid email


Comment

Please enter your comment


Post Comment

Your comment has been submitted successfully. Please wait for admin approval.


Comments

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


New Zealand | 28 September 2016
Weed free crops? Science may have the answer

Australian scientists are working on a revolutionary new way to help farmers rid their crops of weeds. With billions of dollars lost by farmers every year because of weeds, scientists from Charles ...


Puerto Rico | 28 September 2016
Puerto Rico finds unexpected source of growth in agriculture

Puerto Ricans are buying rice produced on the island for the first time in nearly 30 years. They are also eating locally grown mushrooms, kale and even arugula, along with more traditional crops such ...


USA | 28 September 2016
U.S. farmer lawsuits over Syngenta GMO corn granted class status

A U.S. district court judge in Kansas this week said lawsuits brought by U.S. farmers against seed company Syngenta AG over sales of biotech corn seeds not approved for import by China can proceed as ...


France | 28 September 2016
French cows die after eating all winter stock in one night

Almost half of a 50-strong herd of cows in western France ate themselves to death after chomping on the equivalent of a whole winter’s rations in just one night. The farmer in the Loire-Atlantique ...


Japan | 28 September 2016
2 companies pioneering purchases of Japanese farmland

Photo album giant Nakabayashi and home remodeler Sanyo Amnak will become the first businesses to buy Japanese farmland under a new strategic zone regulation aimed at raising agricultural productivity....



Trending Now

Viewed
Discussed


Top stories you may have missed
FarmingUK
FarmingUK Logo

FarmingUK

Labour will end the badger cull and prioritise ending bovine TB, Shadow Def...


FarmingUK
FarmingUK Logo

FarmingUK

A herd of rare White Park cattle could die out if its owners do not urgentl...


FarmingUK
FarmingUK Logo

FarmingUK

The UK government is "failing" to support farmers in the long-term accordin...


FarmingUK
FarmingUK Logo

FarmingUK

Retailer Co-op has announced that from May 2017 all of its bacon and lamb w...


FarmingUK
FarmingUK Logo

FarmingUK

Over 50 wildlife organisations have compiled a stock-take of all the UK's n...


FarmingUK
FarmingUK Logo

FarmingUK

In the run up to the EU farm ministers meeting the agricultural sector have...


FarmingUK
FarmingUK Logo

FarmingUK

The RPA must iron out a number of problems that still exist with 2015 BPS p...


FarmingUK
FarmingUK Logo

FarmingUK

Tourism businesses in the countryside are being held back due to the uncert...


FarmingUK
FarmingUK Logo

FarmingUK

A 24 point action plan aimed at revitalising Scotland's sheep sector after ...


FarmingUK
FarmingUK Logo

FarmingUK

A new survey has revealed that the vast majority of British consumers belie...


closeicon
Username
Password