Maintaining barley yield potential at T2
David Leahy, Business Development Manager
In the second of BASF’s Funginar series, entitled Barley Disease Control, David Leahy, BASF’s Business Development Manager in Ireland discussed how to manage disease in the face of the challenges which the barley crop is facing.
“Barley is sink limited and as such the yield is dictated by the number of tillers and therefore ears that the crop produces. Everything we do with the barley crop early in the season has a knock-on effect. By controlling primary disease there is a positive effect on secondary diseases such as Ramularia.
T1 timing- Protecting yield potential
Ultimately the T1 spray is all about protecting the yield potential early on. Primary disease control of Rhynchosporium, Net Blotch and mildew is fundamental, allowing tillers to be retained and so maximising yield.
Xemium® is the most effective active ingredient on Rhynchosporium, which AHDB Fungicide Curves confirm.
In barley there is an over reliance on the use of prothioconazole and so if growers are using it they should partner it with an active that is carrying at least as much weight. Trials have shown that Xemium® in a mix with prothioconazole increases its performance quite dramatically.
There is a correlation between good levels of Rhynchosporium control and low levels of Ramularia. Rhynchosporium infection is acting as a stress on the crop and reducing crop stress is critical to delaying the onset of Ramularia.
Net Blotch is a challenge, this disease is showing reduced sensitivity to SDHIs and QoIs alongside an erosion of prothioconazole effectiveness, to the point that now prothioconazole can no longer be relied on to achieve adequate Net Blotch control.
F500® is now the cornerstone for optimum Net Blotch control. This is because of the F129L mutation. F500® is the most effective strobilurin on this mutation. A balanced mixture of F500® + prothioconazole is stronger than any alternative and in our trials the inclusion of F500® gave good control which transferred into yield. If net blotch is a concern, then we need to be using F500® in mixes.
With the loss of fenpropimorph growers need to avoid getting themselves in a position where high levels of knockdown are needed on mildew. Although fenpropidin will offer eradication of this disease it is hard on the crop, and so can pre-dispose it to Ramularia. Prothioconazole remains strong on mildew in preventative situations.
T2 timing – Maintaining yield potential
Ultimately the T2 timing is all about maintaining the yield potential of the crop and the importance of this timing in barley is increasing. This is because the loss of chlorothalonil (CTL) and Ramularia’s reduced sensitivity to SDHIs, QoIs and conventional azoles means this disease is very much in the spotlight now.
Brackling, which is exacerbated by Ramularia, is also an issue for modern hybrid varieties as well as high yielding spring barley varieties. Straw is a valuable commodity and Xemium® continues to set the standard on reducing straw breakdown. In Ireland, almost all barley crops are receiving an application of Xemium at either T1 or T2.
Revystar® XE, with its combination of Xemium® and Revysol® is ideally suited to the T2 timing. Not only does it ensure prolonged Rhynchosporium control, but it also brings straw benefits too. The Revysol® component is the strongest active on Ramularia, and good Ramularia management can have a positive effect on straw brackling, making Revystar® XE very powerful and effective chemistry at this timing.
From a resistance management perspective, using Revystar® XE at T2 also limits an additional use of prothioconazole within a cereal fungicide programme.
Stress management
Control of primary diseases can delay the onset of Ramularia as can stress management of abiotic factors: both Xemium® and F500® can help to alleviate drought stress. Including F500® either in mix with Xemium® or in the form of Comet® 200 at T1 and at T2 also has a role in terms of reducing crop stress, its use can cause a reduction in the amount of ethylene the crop produces and promote green leaf area.”
Use plant protection products safely. Always read the label and product information before use. For further product information including warning phrases and symbols refer to www.agricentre.basf.co.uk. Revystar® XE contains mefentrifluconazole (Revysol®) and fluxapyroxad (Xemium®). Comet® 200 contains pyraclostrobin (F500®). Revystar®, Comet® 200, F500®, Revysol® and Xemium® are registered Trademarks of BASF. All other brand names used on this publication are Trademarks of other manufacturers in which proprietary rights may exist. © BASF 2021. All rights reserved.
