Now is the time to monitor wheat crops for signs of take-all, with information on this season’s incidence key to formulating a strategy to reduce its impact in following crops.
The 2017-18 season has been mixed in terms of take-all risk factors according to Certis’ Technical Specialist, Geoffrey Bastard, which can make disease pressure hard to predict.
“Although the cold winter may have slowed the development and spread of the disease, there’s always a risk of disease carry over,” he says.
“The waterlogged soils are a prime breeding ground for the take-all pathogen and combined with mildew infection in the autumn, may have hindered rooting and left plants susceptible to the disease.”
Unlike other cereal diseases, Geoffrey explains take-all is always in the background posing a risk to yield.
“When temperatures rise this spring, the disease could spread quickly,” he says. “Symptoms are likely to appear imminently, particularly in min-till situations, where crop debris left on the surface could host traces of the pathogen.”
Although there is little that can be done in-season for crops showing take-all symptoms, Geoffrey urges growers to assess disease pressure, to identify the risk for second cereal crops drilled in the upcoming autumn.
“Usually, growers will use early nitrogen applications to help plants grow away from the disease, but these have been delayed by the weather and it may now be too late.
“Implementing an integrated management approach to minimise its impact for next season’s crops should be the priority,” he says.
Variety choice, later drilling and compaction free soils with good drainage can all form part of a robust control programme for take-all in second cereals.
An important part of any control programme is a take-all active seed treatment, such as Latitude (silthiofam), which creates a protective zone in the soil to protect the roots against the pathogen.
“We’ve seen an average yield improvement of 0.55t/ha in second wheats and approximately 0.25t/ha benefit in winter barley, plus improvements in specific weight,” explains Geoffrey.
“Don’t take the risk with second cereals. Take-all infection is always possible, so use every tool available to mitigate the impact of this hidden yield robber.”
Take-all – what is it and where are the risks?
- Take-all is a soil-borne fungus which attacks the roots of host plant
- It commonly affects second and third wheats, winter barley following a cereal and first wheat after fallow or a spring cereal
- Infection initially appears in distinct patches of stunted plants with blackened roots
- At harvest plants have “bleached” ears, commonly known as whiteheads, containing pinched or no grains
- It can thrive in all soils, but lighter and/or alkaline are highest risk
- Symptoms are exacerbated by poor nutrition, drainage or soil pH
- Cereal volunteers and grassweeds can bridge the disease over into following cereals
Take-all management tips for 2018
- Assess take-all levels in cereal crops now to identify next season’s risk
- Reduce its impact with an integrated management plan
- Healthy soils, twinned with good establishment and nutrition is key
- A seed treatment can help protect yield in second and third cereal crops