Given the unseasonably high temperatures, Teagasc is advising growers to check for disease levels in rape and cereal crops now.
Above normal temperatures in most areas during the month of November have resulted in cereal and rape crops continuing to grow quite rapidly.
However, these enhanced growth rates have also been accompanied by a degree of disease threat.
Oilseed rape and cereal crops
Teagasc’s head of crops with the Knowledge Transfer Department, Michael Hennessy, explained that oilseed rape crops have now been in the ground for a considerable period of time.
“The main disease threats her are light leaf spot and phoma. Light leaf spot is the disease that has the potential to really damage the yield potential of crops next year,” he explained.
“With this in mind, we are strongly advising growers to go in with a spray mix of metconazole and tebuconazole.
“If this step has not been taken, then it should be acted upon as a matter of priority.”
Where cereals are concerned, Hennessy confirmed that disease levels in later planted crops of winter wheat are relatively low.
“There would be no justification for spraying these crops with a fungicide,” he commented.
“The one exception to this rule of thumb relates to very odd crop of barley.
“In specific cases where plant numbers are low and there is evidence of net blotch and mildew within the crop, there would be a strong case for getting a second opinion, if the option of putting on a fungicide is being seriously considered,” he said.
“Spraying at this stage will not kill the infection: rather it will act to protect the fresh growth that occurs during the early weeks of next spring.”
Disease levels
Hennessy pointed out that the main disease threats in cereals at this time of the year are usually found in barley crops that have directly followed a spring barley or a previous winter barley.
According to the Teagasc tillage specialist, ground conditions remain excellent in most parts of the country.
“So getting out with a tractor and sprayer should not be a problem, if required,” he added.
Hennessy went on to point out that heavy frosts, should they become an issue over the coming weeks and months, will kill off old leaves.
But it will not reduce the overall yield of those cereal and rape crops that are now in the ground.
Teagasc is advising growers to monitor crops for pest damage such as slugs. However, in most cases there are enough tillers and leaves to survive most attacks.
Oilseed rape crops are also very forward and in many cases are quite tall; this should help to ensure that pigeon grazing should be limited.