Spring T2 choices
Key Points in this Technical Bulletin
Winter wheat
- Decisions made at T2 have lasting consequences for the rest of the season
- Apply T2 fungicides at full flag leaf emerged. SDHIs do not require the leaf to be fully unrolled,but CTL needs complete leaf coverage
- Although crops may look clean, it is only now that the effects of any missed / reduced T0s and T1s will become apparent as Septoria moves out of the latent phase, even on stronger varieties
- Have you protected your investment?
- T1 timing crucial for yield building in barley
- Get your crop off to a flying start and prepare it to fight off later season disease
Recommendations – Winter Wheat
- The sensitivity of SDHIs and older azoles have continued to slip over time
- SDHIs continue to be a crucial part of Septoria suppression, and need to be protected by the strongest mix partners
- The strongest control of Septoria available on the market at T2
- Includes Revysol®, taking us back 15 years to a level of Septoria control achieved from Prothioconazole and Epoxiconazole when they were first launched
- Even in the low disease pressure season of 2019, Revystar® XE continued to outperform
Winter wheat choice at T2
The choice at T2 is clear. Apply Revystar® XE at 1.0 l/ha. Add 1.0 l/ha CTL if applied before 20 May. Whatever you decided to apply at T1, the subsequent weather conditions have ensured that Septoria will almost certainly be present in the latent stage in final L2 and depending on timing possibly in the Flag leaf. This has been the case over the past three seasons where, despite varying weather conditions there has been a consistent message from our CuraCrop survey.
Leaf samples from 160 crops around the UK were collected just prior to the Flag Leaf spray application were analysed for the amount of Septoria DNA (qPCR) that was present inside them. Not surprisingly at this time of the season the lower leaves (3&4) were infected in most cases. However, the upper leaves told a different story. External visual assessment suggested no disease infection and indeed this is what most growers whose samples were taken confirmed. When tested however the upper two leaves were shown to have already been infected but the disease was in its latent phase before symptoms could be seen. So inevitably at least one of the upper two leaves is likely to already be infected by the time the T2 spray is applied.
You need the strongest curative product available to ensure that your yield is not jeopardized. This is of particular importance if the T1 was of the “cheap & cheerful” type. Revystar® XE brings you both strong curativity (or kickback) from Revysol® as well as combined long-term protection from Revysol® and Xemium® especially if bad weather delays the application.
Source: 4 x 2019 BASF-funded trials done by ADAS, NIAB TAG, Scottish Agronomy and Teagasc in UK and IE. All treatments applied at 80% dose with no T1 or T3. Untreated yield = 7.62 t/ha
Spring barley choice at T1
If managed correctly, spring barley can deliver very good returns, through increased yield and increased quality. After the difficult autumn we experienced in 2019, spring barley will now occupy more prime slots in arable roatations. This has immediately got spring barley off to the perfect start and it is important give them the best opportunity to maximise your return on investment.
Remember that unlike wheat, barley needs the greatest love and attention at the T1 timing rather than T2. So, the first fungicide application usually applied at the end of tillering (traditionally when the rows meet) and the very start of stem extension at GS 30-31. It moves through its growth stages very quickly, so it is important to be prompt with this first application so that you don’t miss the opportunity to maximise yield.
Whilst doses can be reduced compared to the winter crop it is important to consider the disease pressure as the crop goes into stem extension. Be aware that as well as controlling foliar diseases such as Rhynchosporium the crop is prone to brackling and so straw quality and strength is important as with so much being grown this year it is unlikely that harvest date will be optimised in every case and the crop is notorious for not enjoying being left to over ripen. Using Xemium®, pyraclostrobin and prothioconazole based fungicide programmes at T1 to strengthen your straw and protect against all major diseases. This will ensure that the crop is in good order for the second spray which should target Ramularia. There is evidence that Ramularia symptoms are worse if the crop is stressed by disease or weather and whilst we can do nothing about the weather, we can ensure that the crop is as “happy” as it can be.
Revystar® XE has activity against Ramularia and should be considered at T2, particularly where this occurs after 20 May and CTL can no longer be used.
Disclaimer
Revystar® XE and Revysol® are registered trademarks of BASF. Revystar® XE contains Revysol® and Xemium®. Revysol® contains mefentrifluconazole. Xemium® contains fluxapyroxad., Always read the label and product information before use. For further product information including warning phrases and symbols, you can refer to agricentre.basf.co.uk © BASF 2020 | All rights reserved.
