Wheat and barley is approaching T1
Our Innovation Centres have been trialling our adaptive disease management approach. Disease programmes were set at the start of the season and have been adapted according to drilling date, variety, location and weather, which has certainly made applications difficult. Some T0 applications have been delayed as a result of the rain which has been consistent throughout March. Most places have had well over the average rainfall, with some places recording three times the norm for March (well over 100 mm).
After the recent rainfall many wheat crops are now at GS30-31, with leaf 4 emerged, although the weather has meant some crops have not received a T0 application, many will be applied this week. With the rise in temperatures this week crops will develop quickly, potentially reducing the time between growth stages and leaf emergence. On normal or later drilled crops this means there is less time for the emerging leaf 3 to become infected before it reaches full emergence and is ready for its T1 application, especially if the weather remains warm and dry.
On some early drilled crops the rain in March and early April has spread Septoria, which may have infected leaf 3.
Rust is also being seen in susceptible varieties with the warm weather accelerating disease development.
Your T1 application provides a defence line to reduce potential disease transmission up the plant, which will relieve the pressure on the critical flag leaf spray at T2. If the T1 timing is brought forward to compensate for lack of a T0, this will potentially compromise the T1-T2 interval making T2 more curative. Preventative applications for Septoria are critical because good curative action is not available. The aim of T1 should be to provide persistency of disease control on leaf 3 to prevent disease damage to leaves which significantly contribute to yield.
Iain Hamilton - Senior Field Technical Manager
If you’ve applied a T0 continue with your planned approach and apply T1 at the optimum timing of leaf 3 at ~80% emergence. Consider adapting your T1 rate according to drilling date and disease levels.
If you haven’t been able to apply T0 and the crop is not yet at optimum T1 timing, consider applying a T0 even if T1 is only 7-10 days away.
If T0 has not been applied and the crop is now at the optimum T1 timing, you may need to adapt your T1 application. Consider increasing the dose rate and moving to an SDHI-based treatment if one was not previously planned.
With the wet weather over winter some crops are poorly rooted, whilst T0 is a more effective timing to stimulate rooting, ADAS results* have shown there is still a significant positive impact from T1 PGR applications of Moddus.
In barley most crops did not receive a T0 application and crops are now at or approaching T1, a critical timing for keeping lower leaves clean, which contribute more to yield than in wheat. Net blotch and brown rust are both visible, depending on variety and situation. Adapt your T1 application to account for drilling date, variety, location, weather and disease.
* 2015 ADAS controlled study
The Syngenta Innovation Centres are specialist sites spread throughout the UK, with technical field experts trialling conditions, varieties, treatments and techniques to provide advice for agronomists and farmers. Come along to one of our open days to learn more about their research, and how it can benefit your crops. Find the dates and locations here.