South: T1 fungicides and scelerotinia control

The dry weather is taking its toll on all crops particularly spring barley on the light ground where parts of fields are dying and have needed treatment with trace elements. Winter wheat crops are also showing signs of severe leaf tipping indicating nitrogen deficiency caused by the near drought conditions.

There is temptation to reduce fungicide rates but careful planning is required bearing in mind that there have been heavy dews at night, which is just enough to spread disease. I have a field of Warrior winter wheat breaking out with yellow rust under these hot conditions and this has a resistance rating of nine. Strange things are happening out there.

Winter wheat crops have been treated with strobilurin-based fungicide Nebula (boscalid + epoxiconazole + pyraclostrobin) to help the light land crops against septoria and guard against yellow rust. Many varieties have septoria on leaf four and the variety Conqueror is covered in mildew.

Winter barley is at the awn emergence stage GS 49 and will soon need the second fungicide. It has been a dilemma  weather to apply the late plant growth regulators to this crop as the majority of the nitrogen applied remains in the ground. But if we get rain in May the barley will make compensatory growth and there could be risk of serious crop lodging.

Most oilseed rape crops are looking good and have up to 46 pods on the main raceme, however some crops are disappointing where a large number of pods are missing and in some instances the crops are refusing to flower. There have been reports this is the result of heavy pollen beetle attack, but other factors such as frosts early in April which resulted in pod loss and in some instances the loss of whole bud cluster soon after their appearance have been responsible. However, I believe the main reason for the loss of pods are the drought conditions prevailing at present forcing the plants to shed off the excess growth.

Most oilseed rape crops are at 30% petal fall stage and ready for the sclerotinia fungicide. Remember May 2007 was a dry month but we had catastrophic sclerotinia problem.

See more