12 April 2002

Dry weather offers T1 spray cost economies

By Andrew Blake

DONT panic if recent winds and overnight frosts have disrupted T1 cereal fungicide spraying. The cold spell has eased disease pressure and could offer some savings.

That was the re-assurance from ADAS, independent agronomists and the trade earlier this week, with a forecast of continued cool but mainly dry weather.

Despite reports of Soissons wheat with leaf two emerging and Siberia barley at flag leaf, most wheats are only just reaching T1 treatment stage.

Chilly winds over the weekend hampered spraying, but also reduced disease pressure, says ADASnational crop specialist John Garstang.

"Its easy to get over-anxious about the weather. But where leaf three is coming out you do need to keep it protected from septoria, so you have to be ready to take every spraying opportunity."

Dick Neale, of Cambs-based distributor Hutchinson, agrees. "Crops are generally very clean. But I would urge growers to apply some sort of T1. The worry is that if the weather breaks big style we might not get on again for a month."

A strobilurin for early drilled more responsive varieties, like Napier, Savannah and Tanker, could be justified, says Herts-based AICC member Peter Taylor. "But for more conventional second wheats drilled in October we are looking at a lower cost programme and reserving the main strob hit for the flag leaf.

"With fungicide programmes costing £50-60/ha and grain prices as they are, you need a 10-12% response in a 10t/ha crop, which we didnt get last year. You have to be very careful.

"If it is really needed we might use one of the older strobs like Landmark or Amistar at T1. But the price of Opera makes you look really hard at how you use it."

"Spending a vast amount at the moment is probably not the way to go," agrees Mr Neal. But growers still need to base sprays around a good protectant strob, such as Amistar, Acanto or Twist, he suggests. "0.5 litres/ha gives you the flexibility to mix in a low 0.25-0.3litres/ha dose of triazole, which should keep the crop clean to GS39, the high return period."

Hampshire Arable Systems Steve Cook says that apart from some active pockets of mildew in valleys, disease levels are generally low and most crops were still only starting to extend at the beginning of the week.

"But its important not to be lulled into a false sense of security." Septoria remains latent on leaves four and five ready to move up unprotected crops, he adds.

"We shall be using strobs at T1, mainly Twist, because you can go to quite low doses and still get a response. And well use Acanto, which is very well-priced, if there is any rust about.

"For second and third wheats it will be Amistar for its take-all and sharp eyespot effects." The latter was a problem in second crop Malacca last season. &#42

&#8226 Most crops only just ready.

&#8226 Disease pressure generally low.

&#8226 Some protection still essential.

&#8226 Potential savings on strobs and late herbicides.

Low disease pressure is helping growers cut back on T1 fungicide costs, allowing spending to be reserved for the more critical T2 flag-leaf timing, say consultants.