The success or failure of producing a quality silage product can equate to the amount of greenleaf retention achieved. Yield and quality may be compromised by a lack of greenleaf, while grain fill may be reduced when taking the crop to the cheesy dough stage.
Oats
Oats may not be as susceptible to disease, but depending on the variety (newer proprietary cultivars have less disease), the sowing date and weather conditions can attract late leaf rust.
Leaf rust can invade a crop quickly and usually shows close to maturity. Therefore, an application of a registered fungicide, such as tebuconazole, can be beneficial. Note there is a withholding period (WHP) of 28 days for rust at GS 30 to 31 end of tillering to the first node.
In some regions, oats are cut at the milky dough stage. When cut at this point, the crop does not make good silage, with oats being more suited to green chop at the flag leaf. If this is the case, delay the fungicide application to GS 32. Checking the label for the relevant harvest WHP is essential as they can range from 28 to 56 days.
Triticale
With a wide sowing window from late autumn to early spring, triticale may require two fungicide applications for full protection. Crops planted in autumn can accumulate disease, and for this reason, fungicide programmes are generally started at GS 32 second node. The products registered for use are currently limited, but good options are available and will provide dual actives to control disease and future protection to the crop. The second application of a fungicide should be at approximately GS 39 flag leaf. The WHP is 42 days for forage so it is best to plan the spray programme in consultation with your local PGG Wrightson Technical Field Representative.
Barley
Commonly sown from September to November, barley provides a late option to follow winter feeds. There are several specialist cereal silage barleys and other spring varieties that can be taken as a whole crop option.
These barleys, from a disease management perspective, are similar. Barley can attract disease throughout the season, with the major early diseases being scald and net blotch. The timing of applications in a silage crop starts at GS 30 to 31 end of tillering with a triazole and strobilurin option. Then at the early flag leaf GS 37 to 39 stage, use an SDHI in combination with a triazole to control late rusts and Ramularia.
The greening effects in the crop add to both grain and leaf yields providing an overall better-quality product. Early application is advised as the later barley crops can mature quickly resulting in the WHP becoming an issue.
For assistance forming a cereal crop management programme, contact your local PGG Wrightson Technical Field Representative.
