Wheat
Getting the most from your wheat crop means making smart decisions throughout the season to get the best control of threats to your yield from diseases, weeds and pests.
Posted 9 months ago
Getting the most from your wheat crop means making smart decisions throughout the season to get the best control of threats to your yield from diseases, weeds and pests.
Posted 9 months ago
May
There is not likely to be any record wheat yields in 2020 but at least late April saw welcome rain in many places. This should mean the large variation of growth stages between crops starts to even out as crops push on and get hold of the nutrients they need.
Yellow rust pressure will remain depending on situation and conditions. However, the showers and warmer weather has increased the risk of Septoria development, the number one yield-reducer.
T1 sprays should mostly have happened by early May, so decisions this month are around T2 timing, assessing when GS39 is reached so that the flag leaf is fully emerged, and fungicide coverage can be maximised.
The wide range of drilling dates and local weather variations mean flag-leaf emergence is even less consistent than normal, making T2 timing decisions more complex. Full flag-leaf cover at T2 is essential but this must be balanced with other risks, not least the cut-off date of 20 May for last applications of chlorothalonil, if you have it in store.
A shorter interval means a lower percentage of flag leaves fully emerged, but leaving the interval too long means leaf two has a longer period untreated and exposed to disease.
A broad-spectrum product such as Ascra is a good choice for flag leag sprays. It uses a unique formulation of two SDHI fungicides (bixafen + fluopyram) and the most effective azole partner (prothioconazole) to give effective all-round control. And assuming the wet weather continues, a product such as Ascra – which is rainfast in minutes with the Xpro formulation – may prove a wise investment.
Priorities for May:
April
Spring is finally here but the impact of the previous wet weather has left its mark on wheat crops, and this could hinder disease control this season. As fields got drilled at some point between September and late February, the diversity of growth stages seen in the surviving crops poses a challenge in finding the right timing for fungicide applications.
Identifying leaf 3 emergence is crucial to get T1 timing right. With the later drilled crops racing through growth stages and plants dropping the odd leaf, leaf 3 could emerge earlier than you might expect looking at nodal development.
It is always important to avoid compromising T1 protection – but especially in those crops that have not received (and will not receive) a T0 application. Although directly dissecting samples in the field to assess growth is extremely challenging, identifying leaf 3 emergence in crops is crucial to ensure they are fully protected. Richard Cromie, an independent agronomist, shows the 5 key steps to identifying leaf 3 in this video.
T1 sprays this April should consider the crop susceptibility for diseases based on drilling date and disease rating. Even though late drilled crops are likely to be under reduced pressure from Septoria, other threats such as yellow rust, mildew and eyespot should also be considered.
In the current scenario, a flexible, all-rounder product like Ascra (bixafen + fluopyram + prothioconazole) can be ideal where any of those diseases are a concern, but especially Septoria or yellow rust. Ascra’s dose flexibility means it is easily matched to suit varying crop development and disease situations.
For the most resilient Septoria varieties, there is still a place for Proline (prothioconazole) + chlorothalonil but the gap to GS39 must be kept short.
Priorities this April (location dependent):
March
The impact of autumn and winter wet weather is still evident, with a good proportion of the season’s crop area not planted. As we enter March the likelihood of those fields being planted with winter wheat diminishes further.
Perhaps the one small silver lining in this year’s weather is that if and when ground conditions improve, there should be a good opportunity to get on top of black-grass with Roundup in the fields that will now be destined for spring cropping.
For those who have managed to drill winter wheat, consider the scenario you face. If you have any grass-weed concerns, coupled with broad-leaved weeds, then Pacifica Plus is an ideal partner, new for spring 2020. If black-grass is the primary concern then Monolith remains the tried and trusted specialist.
When planning disease control programmes for this season, consider how delayed drilling will influence disease pressure. Any late drilled crops are likely to be under reduced pressure from Septoria however, other threats such as rusts and mildew may be more prevalent.
This combined with the considerable variability likely to be seen in crops this season, means fungicide control and timings could be difficult to judge, and flexibility in dose will be key. An excellent all-rounder, such as Ascra will be ideal in these conditions, and ticks all these boxes.
Priorities this March (location dependent):
February
The impact of autumn’s wet weather is still in full force, with much of the season’s crop area still to be planted. It’s not too late to drill winter wheat in February, but consider carefully variety choice (subject to seed availability) as not all varieties will be suitable to drill this late.
Perhaps the one small silver lining in this year’s weather is that if and when ground conditions improve, there should be a good opportunity to get on top of black-grass with Roundup in the fields that will now be destined for spring cropping.
For those who have managed to drill winter wheat, consider the scenario you face. If you have any grass-weed concerns, coupled with broad-leaved weeds, then Pacifica Plus is an ideal partner, new for spring 2020. If black-grass is the primary concern then Monolith remains the tried and trusted specialist.
During February, also begin to consider how the season will impact disease pressure. Any late drilled crops are likely to be under reduced pressure from Septoria however, other threats such as rusts and mildew may be more prevalent.
This combined with the considerable variability likely to be seen in crops this season, means fungicide control and timings could be difficult to judge, and flexibility in dose will be key. An excellent all-rounder, such as Ascra will be ideal in these conditions, and ticks all these boxes.
Priorities this February (location dependent):
December/January
While in recent years, conditions have been favourable for good autumn black-grass control, it hasn’t worked that way this year. A handful of dry days scattered throughout November has led to further delays to winter wheat drilling.
Far less flufenacet being used in the autumn means there is likely to be a greater grass and broadleaved weed burden in spring 2020. This poses a real risk of big seed returns from a wide range of weeds, if control programmes are not tailored to this different challenge. As a result, it will be vital to frequently assess fields for weed germination and plan to utilise spring herbicides to minimise seed return.
Delayed drilling will have reduced the threat from Barley Yellow Dwarf Virus (BYDV) in the first season without access to Deter (clothianidin). But it is still worth monitoring the AHDB’s Aphid Bulletins, familiarising yourself with BYDV aphid vectors here, and utilise the t-sum calculation to guide when you may have to spray.
Priorities this December (location dependent):
