12 April 2002

T1 spray expenses under review

Wafer thin potential

margins mean T1 cereal

fungicide costs are being

watched closely on farmers

weeklys barometer farms.

Andrew Blake reports

WITH few early treatments needed this season and most T1 wheat spraying starting only this week, our regional representatives are examining its cost-effectiveness harder than ever.

Several express caution over the value of novel chemistry, and there is also concern that product marketing could tempt some growers to abandon good anti-resistance practice.

William Hemus in the midlands sums up the overall mood, which is encouraged by apparently low disease pressures. "We are gambling on very thin margins. When you are on the borderline of profitability you have to ask yourself very carefully whether any extra costs will be worthwhile."

"We are very conscious that our chemical bill has been a bit steep for the past two years, so we are keeping it under close scrutiny," says Giles Porter from Surrey, who had to pull in a contractor for the barley T1 spray after an axle collapsed on his six year-old Cleanacres sprayer.

Most growers say they are paying more attention to growth stages to get the best return from their T1 treatments. "We cant afford to chuck chemicals around at the wrong timing," says Essexs Peter Wombwell.

With new agronomist, Farmacys Paul Johnson, he has been splitting and examining stems weekly to avoid that and ensure leaf three is emerging before spraying.

After two seasons of bad lodging diagnostic tests to determine the need for tackling eyespot are also being used. "It is not cheap insurance, but I am ready to spend the extra £3.70/acre or so for Unix to avoid the problem again," says Mr Wombwell.

Accompanying product at T1 is likely to be Acanto (picoxystrobin). On the generally drought-prone farm he prefers to concentrate spending on early treatments.

Similar tests have found rye-strain eyespot at treatable levels in early sown wheats, necessitating inclusion of Unix (cyprodinil), notes Scotlands Robert Ramsay.

Despite the underlying economy drive no one is considering omitting a T1 treatment. That would be false economy, agrees Mr Johnson (see box).

Sowing date remains a strong driver. With no cereals sown before Sept 20, T1 inputs on Mr Hemuss Warks farm were not expected until about now. "We have never needed a T0 because we are not early drillers, and we stopped spraying against eyespot 15 years ago."

Final choice will rest on ARC advice and the difference in price between the latest and older strobilurins and the triazoles. He tends to allow a couple of seasons for fully independent confirmation of the value of new products.

Results from new chemistry trials in 2001 must be treated with reserve, adds Somersets Chris Salisbury, who expects to be into his T1s about now. "You have to remember that it was an easy disease season last year.

"But we cant afford to compromise yield – 0.5t/ha buys a lot of chemical." Septoria, a constant threat, fully justified a pre-T1 mix of Opus (epoxiconazole) and Bravo (chlorothalonil), he believes.

Follow up is likely to be Twist (trifloxystrobin), with low rate Opus added on the most forward crops, particularly if spraying is delayed. "We know it works." But adviser John Midwood is keeping close tabs on relative prices of the newer strobs, and some might be tried on the highest potential fields. &#42

Peter Wombwell is far from alone in paying extra attention to growth stages this season to ensure T1 spray timings are spot on.

&#8226 West

In Shropshire Sandy Walker is fully prepared to spend more than usual on his small area of August-sown Claire after set-aside under a Smart Farming trial. "It has already had Unix against eyespot on the advice of Masstocks Peter Jones. I knew it was going to cost more from the start, and am doing as he advises to see how it works out."

Programmes for most of his 232ha, due for a T1 this week, are in the hands of Agrovistas Neil Buchanan. "It is hard to give our full attention to wheat when we are busy potato planting," says Mr Walker.

&#8226 North

Acanto (picoxystrobin) appears attractive as the T1 option for Yorks barley, says Catherine Thompson. "It seems good all round, especially against rhyncho, and is not too badly priced."

By contrast Opera (pyraclostrobin + epoxiconazole) for wheat appears rather dear. "But I shall possibly try it on about 60 acres with our highest potential." Main T1 input is likely to be Landmark (epoxiconazole + kresoxim-methyl). "It looks very well priced."

&#8226 Scotland

T1 decision-making is all about "value for money", says Robert Ramsay.But with Landmark pricing policy making it effectively the cheapest way to buy Opus, he believes growers are being encouraged to ignore advice on avoiding resistance. "It is driving us towards breaking the FRAC guidelines."

&#8226 NIreland

Robert Craigs switch from a flusilazole-based T1 spray for his barley in Co Londonderry is having an unexpected side effect. "It means we are having to go for a more robust pgr."

The new fungicide mix, Unix/Acanto, has less growth regulatory impact, he says. "It is slightly more expensive, but I want to be more on top of disease than we have been for the past two years."

Key decisions

Key T1 decisions are whether to use strobilurins or triazoles at this stage, and whether to opt for relatively "mobile" or "immobile" products, says Paul Johnson, who advises on FWs Eastern barometer farm.

"It is mainly to do with yield potential. If you are in the 10t/ha bracket and trying for 12t, my view is that you need to push it with a strob."

For applications at the start of the T1 window "mobile" fungicides, like Acanto (picoxystrobin) and Twist (trifloxystrobin), which spread through the crop, are the most appropriate options, he adds. They offer more flexibility and buy time should the weather intervene or there are large areas to be treated.

"Immobile" products, like Opus (epoxiconazole) and Opera (pyraclostrobin + epoxiconazole), with their better eradicant activity are more suited to the end of the T1 window, he says.