Wet hits cereal spray plans

1 May 1998




Wet hits cereal spray plans

By AndrewSwallow

HIGH disease pressure and lodging risk are forcing a rethink on cereal spray recommendations.

Many crops remain untreated due to the weather, making changes to fungicides and growth regulators vital to keep crops which have good yield potential – clean and standing.

Earlier this week 60% of cereals had yet to receive any fungicide in East Anglia, estimated David Ellerton of East Anglian distributor Procam.

"Many products are on farm but not yet applied. Wheats are reaching GS33 and the third leaf is coming through. There is a lot of septoria there to splash on to it. It is a critical time, growers must make the most of opportunities to get on."

Yellow rust is also starting to romp away in untreated crops of Brigadier and Reaper, he adds.

Rewriting advice

In the west, Profarmas Andrew Wade says 30-40% of wheats are untreated. "Some are at GS33 and have had nothing yet. Lodging risk is high, but they are beyond the stage for straight chlormequat. We are having to rewrite the book on a field-by-field basis."

Andrew Wells, senior ADAS consultant in Notts, is reformulating recommendations where first fungicides have not been applied. "We are stepping up the rates to at least 0.75 litres/ha of a new generation triazole to get more kick-back. Growers need to be prepared to spend money on the crop now," he says. Only a third of wheats and slightly more barley in the area was untreated at the start of the week, he estimates.

Dr Ellerton agrees on the need for eradicant activity. "Good curative action is required where crops have not been sprayed. Do not rely on protective products alone."

Fungicides and PGRs should take priority over nitrogen, he adds. "Crops do not look short of nitrogen and yield potential is still high if disease can be cured and crops kept standing."

Application switch

At Lincomb Farms, Stourport-on-Severn, the pressure to get on with spraying forced a switch from liquid to granular fertiliser. "We need the sprayer available for every possible spraying day," says Tony Symonds. A fortnight of fine weather is needed to get up to date.

"We are taking it field by field, when we can get on. We keep talking to our agronomist and have changed the recommendations several times already."

Where no growth regulator has gone on Mr Ellerton suggests a split dose of half rate Terpal (2-chloroethylphosphonic acid + mepiquat chloride) or Satellite (imazaquin + chlormequat chloride + 2-chloroethylphosphonic acid) as soon as possible. That can be followed by a further treatment at flag leaf. "There are some very lush crops out there."

There are plenty of solutions available, agrees Paul Power of Yorks-based Phoenix Agronomy. Growers should be looking at an ethephon-based product such as Terpal, Satellite or Cerone (2-chloroethy-lphosphonic acid), he suggests. &#42

A common sight this week… sprayers across the land were tip-toeing through soggy fields to recover from massive delays after the wettest April this century. Many crops had received no fungicide or growth regulator, seriously jeopardising yields. Here sprayer operator Geof Lane of Robert Shoves Lillechurch Farms and Contracting, Higham, Rochester, Kent, applies 0.25 litres/ha of Alto 240 (cyproconazole) and 0.3 litres/ha Mallard (fenpropidin) to a neighbours Jacardi wheat.

SPRAY DELAYS

&#8226 Yield potential high, so spray inputs remain worthwhile.

&#8226 Untreated crops must receive curative fungicides.

&#8226 Lodging risk remains high.

&#8226 PGR rethink for GS 33 onward.


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