30 August 2002

Indifferent winter barley yields due to infection?

INDIFFERENT winter barley yields may be due to largely undetected eyespot and take-all in the crop, says Masstock.

Detailed stubble inspections by the companys agronomists show significant take-all and eyespot infections, together with mosaic virus, in winter barley crops across the country.

"When treated well we have seen winter barleys perform well this season," reports Masstock seed and crops manager David Neale. "As a first cereal after grass in Shropshire, for instance, Pearl has produced a handsome 8.6t/ha.

"But barley far too often goes in at the end of a run of cereals where disease pressures are highest and fertility lowest. Our agronomists have found high levels of take-all and eyespot in particular on many of the 2002 winter barley stubbles they have inspected."

Both these diseases tend to be overlooked in the crop, mainly because whiteheads are not apparent in barley, he suggests.

"Yet we know barley can be seriously affected by take-all. We have seen huge take-all problems in crops of wheat grown after spring barley this season, so the disease has clearly been carried over strongly by the previous crop."

Two large-scale split-field trials using take-all fungicide Latitude (silthiofam) in winter barley have shown average yield recoveries of over 1t/ha, lifting yields from a disappointing 6t/ha (2.5t/acre) to nearer 7.5t/ha (3t/acre).

"We shall be extending our split-field trial programme this autumn to look in more detail at the value of keeping take-all at bay in barley." &#42