Better wheat prices justify more complete disease approach

MUCH IMPROVED wheat prices make it well worth doing a complete job of disease control to maximise yields and profits this season, leading cereal disease experts are suggesting.

With disease symptoms already present in crops after the mild, wet start to the year, it’s particularly important to learn lessons from last season, they stress, by beginning control programmes early – rather than risking infections getting out of hand.

“Better grain prices help reduce the risk of growing a cereal, by making it easier to invest in season-long fungicide protection – starting at T0”

David Ranner, Technical Manager, Syngenta Crop Protection UK Ltd

According to Bill Clark, director of leading independent research centre, Brooms Barn, the effective doubling of grain prices over the last year means the economic return from controlling disease has substantially increased.

“Normally wheat price doesn’t have much impact on fungicide input,” explains Mr Clark. “But when it doubles it does. This price hike is unprecedented. Growers should be spending £12 to £14/ha more over a season. That’s assuming they are already at the optimum, which many people are not. The varieties we grow in the UK are very responsive to fungicides,” he adds.

Already Mr Clark says brown rust has been found in wheat and a number of susceptible varieties are being grown, so disease risks appear to mirror 2007. That year, he says a key reason that disease control went wrong was where early season T0 fungicides were omitted – leaving crops unprotected until T1.

However because rust can pass through infection cycles so quickly, a suitable systemic triazole fungicide at T0 can be vital, he says, for example cyproconazole contained in Cherokee.

“Almost all fungicide programmes are designed around Septoria tritici control – and rightly so as it’s still the most important disease in the UK. But T0 is also important for rust control. “By the time we got to T1 last season brown rust was already established. The clear message is brown rust is very likely to be a problem this year – a lot of the varieties are very susceptible. A T0 triazole is absolutely essential – Cherokee fits that bill.”

David Ranner, technical manager for Syngenta, agrees that better wheat prices mean the return on investment from fungicides could be even greater this year – with the total profit from a four spray programme at T0, T1, T2 and T3 having potentially tripled.

Based on average fungicide yield responses over five years of trials, he calculates the profit from a programme of triazole with Bravo at T1, triazole with strobilurin fungicide Amistar Opti at T2, followed by a T3 treatment, increases from £100/ha to around £260/ha as grain price doubles from £80 to current levels of around £160/t.

Additionally, he says if this is preceded with a T0 treatment, it lifts total profit by another £30/ha to over £290/ha when

grain is at £160/t. That compares with a profit of around £110/ha if grain is only £80/t. Typically, a T0 fungicide might cost as little as around £8 - £10/ha, he points out.

“Overall, better grain prices reduce the risk of growing a cereal, by making it easier to invest in season-long fungicide protection,” explains Mr Ranner.

“This year, T0 could be particularly important given the mild and wet start to the year plus rust carryover from last season. Also, preventing Septoria tritici getting a foothold will be important – particularly after early rainsplash events. In line with this, Cherokee is an easy fungicide decision thanks to its strong technical and financial fit.

“Not only does it provide a high dose of triazole active against rust, but also protects against Septoria tritici with triazoles and chlorothalonil – helping guard against resistant strains.”

“With better grain prices, just 50 kg/ha of extra yield covers the cost of 0.75 l/ha of Cherokee applied at T0. Also, because Cherokee is cost-effectively priced, savings from using it at T0 and T1 can make it easier to invest in yield-

boosting strobilurins at T2 and T3.” T0 also has practical benefits with spraying with growers having more wheat this season, Mr Ranner says. Cherokee at T0 also offers peace of mind if the weather is catchy around the T1 timing.

“In summary this season we’re advising growers to consider 0.75 - 1.0 l/ha of Cherokee at T0, dose dependant on disease risk.”