Helpful advice for southern growers this August

Glyphosate can help reduce drying costs

Using Roundup (glyphosate) for pre-harvest desiccation of cereals can have several benefits with evening up stands so that the crop is fit for harvest at the same time one of the most obvious ones.

In barleys, in particular, there has been a lot of side-tillering, so avoiding harvesting green grains will be beneficial for quality.

The approved rate for pre-harvest glyphosate is relatively low, so, with a fair amount of weed in the bottom of some crops after all the rain, bear that in mind when thinking about using glyphosate – if there are big weeds then control levels will be more variable.

Timing in cereals is easier than in oilseed rape – the thumb nail test where you dig your nail into grains to see whether it holds your thumbnail impression is simplest. If it holds the impression the grain will be below 30% moisture content and ready for desiccation.

Remember there is a seven-day interval between spraying and harvest to minimise risk of glyphosate residues in grain.

Consider using a Magic Trap to help time oilseed rape establishment

Timing oilseed rape establishment dates could be made slightly easier using one off our new Bayer MagicTraps. This is a fully automated digital water trap, which autonomously detects, categorises and quantifies a range of insects, including cabbage stem flea beetles.

The best way to use it is not after drilling, but before, to help assess when the main flea beetle migration has occurred into that field and use that information to inform when to drill to avoid migration peaks.

That might mean drilling a bit later than traditionally, which will suit varieties that have quick autumn establishment, such as our range of DeKalb (DK) varieties.

With moisture looking like it won’t be a limiting factor this August currently, some growers will be thinking about drilling oilseed rape in early August. I’m slightly nervous of that approach because it means the subsequent migration could result in higher numbers of larvae, creating a problem in spring.

But if you do choose to drill early, look for a variety that will stand well, but not run away and get too huge before winter.

If you select a DK variety remember to sign up for our establishment guarantee for crops sown before 20 September. Register with the scheme on our website https://cropscience.bayer.co.uk/dkestablishment/ by 30 September and submit claims for any 6ha or larger blocks that have failed by the end of October.

Effective post-harvest stubble management key

With potentially a shorter period between a later harvest than for the past couple of seasons, and growers considering drilling earlier, effective post-harvest stubble management will be even more crucial this season.

There doesn’t seem to be much prospect of moisture being short this season, so encourage a chit of grassweeds like black-grass, Italian ryegrass and wild oats by running a set of shallow discs or tines post-harvest to get a little bit of soil movement.

For bromes, it’s important to know which species you’re dealing with – meadow, soft and rye brome need a period left on the surface to ripen before they will germinate, whereas sterile and great brome need to be buried.

Data and anecdotal evidence suggest that some growers are not using high enough doses of Roundup on stubbles. Growth stage is really important – our trials show that control with 720g a.s./ha of glyphosate reduces from 95% to 80% when the black-grass has two tillers rather than only two leaves.

So it is crucial to walk fields and look at growth stages and type of weeds you’re spraying off.

Spray application is also critical. We’ve seen examples, for example, where sprayer operators have been rushing and going around corners of headlands, where the boom speed increases to much faster than what the sprayer speedo might be saying. That will result in lower deposition of glyphosate, and if you are starting with lower doses, then you are almost certain to be dosing sub-optimally.

Keep blight spray programme intervals to seven days

Blight pressure has been high, although at least we haven’t had too much warm weather to speed up infections. The other good news, at least when this is being written, is that we haven’t had any confirmed reports of the CAA fungicide-resistant strain of blight 43_A1 in the UK, which has caused such problems on the continent.

Our Infinito (propamocarb + fluopicolide) product has been extremely popular this season already. Neither of its two modes of action are affected by the resistant strains identified, so it’s a decent resistance management policy in one can.

But it does have a maximum of four applications in one season. Hopefully you still have at least one available for later in the season, as it is one of the few products with activity against both foliar and tuber blight.

Consider spring herbicide use on land intended for cover crops

Cover crops continue to gain in popularity, not least with payments available via the Sustainable Farming Incentive.

Where you are planning to establish cover crops – and the current moisture levels should help – consider what herbicides have been used this spring, as these could mean cultivations are required to minimise issues with cover crop establishment from herbicide residues.

For example, we know quite a lot of mesosulfuron-based products were used in late March and early April, and we haven’t had a particularly bright sunny summer to help speed up degradation, although the rainfall should have helped.

Those products do have a wide weed spectrum, so cross-check the label for weed species controlled with plant families in your cover crop mix to see how susceptible your cover crop could be.

By the book where there is a risk cultivation to 15cm should be used to minimise risks of cover crop failure.

Analyse yield data with Climate FieldView

Climate FieldView makes obtaining and analysing data easy, with good compatibility through our FieldView Drive to take data from all sorts of machines, including combines.

At this time of year, that can be invaluable in helping farm managers to understand how harvest is progressing if they are away from fields combines are working in, and giving real-time insights into yields, which might lead to further investigations of why fields or parts of fields have performed well or poorly.

For a no-obligation demo, please register interest here: https://cropscience.bayer.co.uk/fieldview