Teagasc Urges Caution in Cereal Disease Control Strategy

31 March, 2003

Dealing with resistance of the disease Septoria to the new strobilurin chemicals is a major challenge for the Irish tillage sector in 2003, according to Teagasc chief tillage adviser, Jim O'Mahony.

A nationwide survey and laboratory testing at Oak Park in recent weeks has confirmed that Septoria resistance is widespread at high levelsto the new chemicals. In recent years, these strobilurin chemicals have contributed enormously to disease control and were one of the factors in Irish growers leading the European and world league in cereal yields in 2000 and 2001.

Jim O'Mahony said that mandatory labelling requirements introduced by the Department of Agriculture and Food specify that only one application of a strobilurin product can be applied to wheat. Also, the first disease control spray must not contain a strobilurin.

"The key challenge for growers will be in deciding whether to use a strobilurin fungicide in the second or third spray. This will depend on the level of Septoria and other diseases on the crop as well as the economic return from using a chemical", said Jim O'Mahony.

He urged growers to consult their Teagasc adviser for advice on timing and type of chemicals to be used in 2003.

On a more positive note, Teagasc has reported rapid progress in tillage operations following almost three weeks of excellent weather. Around 90% of spring cereals and 75% of the sugar beet crop have been planted.

Jim O'Mahony said the first of the maize crop is now sown under plastic. However, he advises that maize should not be sown unprotected until the middle of April.

Jim O'Mahony said the expectation is for a slight reduction in national cereals area this year, due to a big drop in winter wheat planting last autumn and increased use by farmers of the setaside option.

"Wet weather resulted in a drop of over 40% in the area of winter wheat planted last autumn, from a record high of 80,000 hectares in autumn 2001. While up to 15,000 hectares of winter wheat varieties were planted in late January/February, these crops are now suffering from poor establishment. One of the factors contributing to the problem is crow damage", he said.

Expert advice on the Septoria problem and on other topical issues in cereal growing will be provided by Teagasc at 12 special crop walks which are taking place in tillage growing areas over the next three days.