Seven agronomic tasks to consider doing this June and July in the Midlands

Crop Progress

Rain in May has varied between 15-50mm across different parts of the East Midlands, which has helped later drilled spring barley.

Generally wheat crops have moved quickly through growth stages in May, even December drilled after vegetables has romped on reaching booting and perhaps catching some out with the speed of growth.

Most flag leaf sprays have been applied just in time, but latest cut offs for some herbicides have been an issue.

Adam’s agronomy tips for June and July

1. Watch out for smaller gap to ear sprays

With crops rushing through growth stages, be aware of a smaller gap between flag leaf sprays and ear sprays. Some crops have reached ear emergence before the end of May, so sprays targeting early to mid-flowering could be due in the first week of June.

Potentially that could mean there being a long gap between T3 and harvest, which could point towards using a robust product to protect crops for that prolonged period, especially with high commodity prices.

What to apply will depend on what the primary target is – foliar diseases such as Septoria or rusts, or ear diseases such as Fusarium and Microdochium, and what has been applied before.

If you used a non-SDHI option at flag leaf, such as an fenpicoxamid-containing product, then you have the option of using your second SDHI at T3, which can be a useful against both foliar and ear diseases.

Aviator (bixafen + prothioconazole) is one such option at 0.75-1.0 L/ha. If you’re targeting Fusarium, be mindful of keeping the rate of prothioconazole up. At 0.75 L/ha you’re only putting on 120g/ha of prothioconazole, so might need to add in some tebuconazole to top it up.

Where two SDHIs have been used options include Proline (prothioconazole) or Prosaro (prothioconazole + tebuconazole), or if you’ve only used one strobilurin, products like Firefly (fluoxastrobin + prothioconazole).

2. Consider second disease control spray in spring barley

Spring barley crops drilled before or in March, with the rain we’ve had, is looking good, but the later drilled crops that went into dry seedbeds has struggled. As a consequence you have crops at two different growth stages.

Earlier drilled crops definitely received a first fungicide in May, and after the rain many growers are looking to use two sprays this season, especially with barley, like wheat, being worth good money.

If you are going twice, Siltra (bixafen + prothioconazole) at 0.4-0.5 L/ha is a good cost-effective product, with a good loading of prothioconazole and bixafen to cover barley diseases. 

If Ramularia is a particular concern, and you can find some stock, Ascra (bixafen + fluopyram + prothioconazole) is also a good choice with the fluopyram helping on the disease.

3. Plan potato blight programmes

Most potato crops with the warmer weather and moisture, canopies are developing, which will bring attention to both early and late blight.

For early blight (Alternaria), we launched Caligula (fluopyram + prothioconazole) last season. It’s a good option for those susceptible varieties and situations that are higher risk for Alternaria.

There are issues of resistance to Alternaria within strobilurin fungicides, and earlier generation SDHIs. Fluopyram is also an SDHI, and while it is from a different class to others and has an incomplete cross-resistance profile, do follow resistance guidelines, and use cultural controls to help mitigate that resistance risk.

Caligula doesn’t have any activity on late blight, so will need mixing if late blight threatens.

Plan late blight programmes carefully. Infinito (propamocarb + fluopicolide) is an option to use through most of the season with its strength against both foliar and tuber blight. There are fewer options for tuber blight control, but with four applications available through the season, it’s possible to use at different points of the season.

4. Option for third foliar insecticide spray in sugar beet

The beet industry has successfully applied for an emergency approval for Movento (spirotetramat) for the control of Myzus persicae aphids transmitting virus yellows in sugar beet.

But it does come with some tight restrictions. It can only be used on crops which haven’t been treated with Cruiser (thiamethoxam) neonicotinoid seed treatment, and in those crops it can only be used as the third spray after applications of Tepekki / Afinto (flonicamid) and Insyst (acetamiprid).

It should also only be used when thresholds have been reached – one wingless aphid per four plants up to 12 true leaves, or one per plant from 12-16 TL.

It will give around 10-14 days protection against Myzus, but it will take 2-3 days after application before you start seeing the results of the application because of its mode of action.

For those who have Escolta (cyproconazole + trifloxystrobin) in spray stores for disease control, a quick reminder this is the last season of use, so use up any stocks as the first application in the crop at the onset of disease.

5. Don’t go too early with oilseed rape desiccation

For those planning to desiccate oilseed rape crops with Roundup (glyphosate) towards the end of June and into July, it’s important not to go too early as this can reduce yield and oil content and increase unwanted red seeds which can cause rejections.

You’re aiming for below 30% moisture content before you spray. Take 20 pods from different areas of the field, and if two-thirds of the seeds in at least 15 of the pods have changed colour from green to brown, you’re good to go.

There is a 14-day statutory harvest interval after application, and don’t treat any crop that is going to be used for seed.

6. Use thumbnail test for cereal harvest management

Many of the same considerations apply if you’re going to apply glyphosate to cereals for easier harvest management. Don’t go too early and limit yields or treat crops intended for seed. There’s a 7-day harvest interval and check any end market restrictions.

Timing is the same – under 30% moisture content. Use the thumbnail test to check. If your thumbnail imprint holds in 20 grains it should be 30% or under. Alternatively you can cut wheat grains in half and look for a dark brown strand in the crease. If 75% of grain are marked the grain is at 30%, if all of them are, it’s under 30%.

Rates range from 360 to 1440 g/ha depending on situation with higher rates where you’re also trying to control perennial or difficult weeds.

7. Consider spraying off bad grassweed patches

While people were relatively happy with the residual herbicide performance in the autumn, but perhaps off the back some decided not to go with a mesosulfuron option in the spring, and subsequently, unfortunately, we’re seeing quite a lot of the black haze of grass weeds coming through in significant populations.

While it’s never an easy decision to spray off patches, and definitely not at current prices, some of these patches are not going to yield. If you know that black-grass is resistant to in-crop chemistry you don’t want that seed setting and becoming viable for future years.

I’ve already seen some areas that look like they have been sprayed off, which is a bitter pill to take, but is an option worth doing for longer term integrated weed management. Don’t delay once heads appear, it needs doing before seed becomes viable.

Digital technology, such as FieldView, can help identify infestations through satellite imagery, create applications maps so you know exactly how much glyphosate you’ll need, and then uploaded into sprayers, especially with section or individual nozzle control, for precise application.