Disease levels rise in tandem with temperatures
Published 13/05/2015 | 02:30
Despite the beautiful weather of late April there was little growth due to the very cold and frosty nights. While last week saw lots of rainfall, temperatures remained low and growth has continued to stall.
Winter crops have been under pressure during the cold spell with poor growth but this has helped to keep disease levels low. The improved moisture availability and hopefully improved temperatures this week will change this. This should lead to rapid growth and invariably an increase in disease levels.
The poor weather has made it very difficult to apply the T1 to wheat and barley. Disease levels, particularly Septoria, may start to get a foothold and should receive immediate treatment to remain in control of this disease over the next few weeks.
It is imperative that a very robust rate of a Triazole plus an SDHI is now used, if not already sprayed.
While barley crops have been relatively clean and particularly short to date we can expect this to change suddenly with the main fertiliser application kicking in due to the weather change.
With many crops more backward and shorter than normal a second growth regulator might have been avoided. However, especially for hybrids, if awns have not yet appeared it may be appropriate to apply Cerone at this stage as rapid growth will lead to weak stems and possible lodging problems later on.
Barley should also receive a strong fungicide application of either Bontima, Ceriax, or Siltra. Winter oats has also remained relatively clean and, while still relatively short, may benefit from a late growth regulator such as Moddus plus CCC. Do not apply Moddus past growth stage 32 to oats. A broad spectrum fungicide such as Tocata or Capalo could be used.
Nitrogen top dressing of winter crops is mostly completed with applications of at least 210kgs/ha on winter wheat; 180kgs for winter barley and oats to 145kgs.