T0 or No T0….
Posted 10 years ago
15/04/2016
Protecting your crop against Septoria
The problem
Septoria remains the single most prevalent disease in winter wheat and can result in severe yield penalties when not controlled effectively. With the current weather in the UK, T0 applications are at risk of not going on but they are vital to the start of effective management of Septoria.
What to do?
The problem
Septoria remains the single most prevalent disease in winter wheat and can result in severe yield penalties when not controlled effectively. With the current weather in the UK, T0 applications are at risk of not going on but they are vital to the start of effective management of Septoria.
What to do?
|
Scenario |
Recommendation |
|
1) Not managed to apply T0 yet |
Get T0 on if possible and follow with T1 at final leaf 3 on main tiller just fully emerged. T1 options include Proline 0.55 L/ha min + CTL or Aviator 1L +/-CTL. If you think leaf three will be fully emerged within 7 days then possibly consider scenario 3. |
|
2) T0 not yet applied AND •Plan to omit T0
•Apply T1 early with leaf 3 half emerged
|
Avoid this option because systemic fungicides move in the xylem to the leaf tip not backwards in the leaf through the phloem, so disease control on the lower part of the leaf 3 would be compromised and receive no fungicide until T2 |
|
3) T0 not yet applied AND •plan to omit T0
•Apply T1 at final leaf 3 on main tiller fully emerged
|
This strategy is ok but please be aware of the following: •If T1 gets delayed due to adverse weather the crop may be compromised
•If the T1 is the first spray, Aviator 1L + CTL will give a good balance of curative Septoria control on leaf 4 and best protectant activity on final leaf 3
•But if any rust is visible, drop out the CTL and use Aviator at 1L/ha with optional additional rust active strob for quicker rust knockdown
|
|
4) T0 not yet applied AND •T1 gets delayed due to weather conditions so leaf 3 has been fully emerged for more than 1 week
|
The crop will have been compromised. Apply Aviator 1L/ha as soon as you can get on (adding rust active strob if rust is present) and then follow with T2 at standard time i.e. flag leaf on main tiller just fully emerged. |
In all situations, the standard 4 spray program always produced the highest yielding crops.
• Omitting your T0 spray had a larger effect than a delayed
T1 spray
• If you missed your T0 spray and had a delay to your T1 application, it could cost you up to 1 t/ha in yield
• In all compromised scenario’s, either through the missed T0 or delayed T1 application, you benefited from the extra protection of Aviator at 1L/ha.
• Omitting your T0 spray had a larger effect than a delayed
Protecting your crop against Septoria
The problem
Septoria remains the single most prevalent disease in winter wheat and can result in severe yield penalties when not controlled effectively. With the current weather in the UK, T0 applications are at risk of not going on but they are vital to the start of effective management of Septoria.
What to do?
The problem
Septoria remains the single most prevalent disease in winter wheat and can result in severe yield penalties when not controlled effectively. With the current weather in the UK, T0 applications are at risk of not going on but they are vital to the start of effective management of Septoria.
What to do?
|
Scenario |
Recommendation |
|
1) Not managed to apply T0 yet |
Get T0 on if possible and follow with T1 at final leaf 3 on main tiller just fully emerged. T1 options include Proline 0.55 L/ha min + CTL or Aviator 1L +/-CTL. If you think leaf three will be fully emerged within 7 days then possibly consider scenario 3. |
|
2) T0 not yet applied AND •Plan to omit T0
•Apply T1 early with leaf 3 half emerged
|
Avoid this option because systemic fungicides move in the xylem to the leaf tip not backwards in the leaf through the phloem, so disease control on the lower part of the leaf 3 would be compromised and receive no fungicide until T2 |
|
3) T0 not yet applied AND •plan to omit T0
•Apply T1 at final leaf 3 on main tiller fully emerged
|
This strategy is ok but please be aware of the following: •If T1 gets delayed due to adverse weather the crop may be compromised
•If the T1 is the first spray, Aviator 1L + CTL will give a good balance of curative Septoria control on leaf 4 and best protectant activity on final leaf 3
•But if any rust is visible, drop out the CTL and use Aviator at 1L/ha with optional additional rust active strob for quicker rust knockdown
|
|
4) T0 not yet applied AND •T1 gets delayed due to weather conditions so leaf 3 has been fully emerged for more than 1 week
|
The crop will have been compromised. Apply Aviator 1L/ha as soon as you can get on (adding rust active strob if rust is present) and then follow with T2 at standard time i.e. flag leaf on main tiller just fully emerged. |
In all situations, the standard 4 spray program always produced the highest yielding crops.
• Omitting your T0 spray had a larger effect than a delayed T1 spray
• If you missed your T0 spray and had a delay to your T1 application, it could cost you up to 1 t/ha in yield
• In all compromised scenario’s, either through the missed T0 or delayed T1 application, you benefited from the extra protection of Aviator at 1L/ha.
• Omitting your T0 spray had a larger effect than a delayed T1 spray
• If you missed your T0 spray and had a delay to your T1 application, it could cost you up to 1 t/ha in yield
• In all compromised scenario’s, either through the missed T0 or delayed T1 application, you benefited from the extra protection of Aviator at 1L/ha.
Is it really final leaf 3?
Ensuring the T1 application is targeted at final leaf 3 is essential to ensure the full benefits of this spray timing are achieved.
Following guidance from the AHDB cereal growth guide, it is clear that there is room for ambiguity as final leaf 3 can emerge anytime between GS 31 and GS 33. Simply counting the nodes present on the stem can be used as a ‘crude’ assessment of growth stage but will not identify exactly which leaf has most recently been exposed. To be sure final leaf 3 is present at application of T1, it is essential to dissect the plant and count the number of leaves rolled up internally within the stem.
Source: AHDB Cereal Growth Stages – a guide for crop treatments
• If you missed your T0 spray and had a delay to your T1 application, it could cost you up to 1 t/ha in yield
• In all compromised scenario’s, either through the missed T0 or delayed T1 application, you benefited from the extra protection of Aviator at 1L/ha.
Is it really final leaf 3?
Ensuring the T1 application is targeted at final leaf 3 is essential to ensure the full benefits of this spray timing are achieved.
Following guidance from the AHDB cereal growth guide, it is clear that there is room for ambiguity as final leaf 3 can emerge anytime between GS 31 and GS 33. Simply counting the nodes present on the stem can be used as a ‘crude’ assessment of growth stage but will not identify exactly which leaf has most recently been exposed. To be sure final leaf 3 is present at application of T1, it is essential to dissect the plant and count the number of leaves rolled up internally within the stem.
Source: AHDB Cereal Growth Stages – a guide for crop treatments