Seven tasks to complete this June and July in crops in East Anglia

Crop Progress

Last year crop growth stages were unseasonably late, this year unseasonably early. I don’t remember a season being this early before, with growth stages 10-12 days ahead of last season.

Wheat crops have rushed through the top two leaves and ear emergence, perhaps because of a minimal amount of rain, warmer temperatures and little bit of crop stress.

On lighter land the lack of rain might have impacted on yield potential, although some growers have irrigated wheat, but there is still good potential in lots of crops. Maintaining green leaf area is going to be important when looking at crops that potentially might senesce a little bit earlier this year.

James’ agronomy tips for June and July

1. Assess location, variety and previous programme for ear sprays in wheat

Ear sprays will depend a little on situation and location, variety and what you’ve applied before. In East Anglia there will still be a risk of foliar diseases, such as brown rust, but also late Septoria which we saw a lot of last year. That risk will depend on varietal susceptibility.

What you’ve done before will dictate what options you have available at T3. For example, if you haven’t already applied two applications of an SDHI-containing fungicide then there is the opportunity to use Aviator (bixafen + prothioconazole) at T3.

That could be the case if you have used a fenpicoxamid (Inatreq) product at T2, or cheaper non-SDHI containing products at T1.

Aviator’s Xpro formulation brings physiological benefits such as prolonged crop greening and mitigating stress as much as any fungicide can do. Bixafen will help against brown rust and late Septoria, while prothioconazole is particularly strong on ear diseases such as Fusarium.

If you’re particularly targeting Fusarium then ideally you need 150g/ha prothioconazole, so either 1.0 L/ha of Aviator or 0.75 L/ha and top up with some extra prothioconazole. For Fusarium timing should be no later than mid-flowering and it’s better to be on the early side than late. Once flowering is finished the benefits of an ear spray are limited to foliar disease control.

For a non-SDHI option, consider Proline (prothioconazole) at 0.4-0.55 L/ha. If brown or yellow rust are active in crops, consider adding tebuconazole or a strobilurin.

2. Top up spring barley disease control

Later drilled spring barley crops are improving after recent rains, but that could also encourage disease. For those on a two-spray strategy the second spray will likely be due in early June when awns are emerging.

Options include Siltra (bixafen + prothioconazole) or Ascra (bixafen + fluopyram + prothioconazole). Ascra can only be used once in the crop, but it’s extra activity against Ramularia makes it an attractive option at T2 in spring barley, if you can get hold of some. Siltra is a very reliable product that has been the standard in barley for many years for good reason.

3. Plan potato blight strategies

There was a big variation in potato planting dates, with the area slightly reduced off the back of input price rises not being tracked by commodity prices. Most crops have emerged and are growing strongly as we enter June.

Use blight forecasts and alerts to help monitor when risk of late blight is increasing. Blight watch, for instance, will send you an alert whenever a Hutton Criteria – two consecutive days of temperatures above 10C and at least six hours of 90% relative humidity is forecast for your region.

Think about blight strategies for control. Infinito (fluopicolide + propamocarb) can be used up to four times at 1.6 L/ha during the season and gives both foliar and tuber blight efficacy. A sound strategy is to use Infinito in alternation with other fungicides from canopy complete through to haulm destruction.

Early blight (Alternaria) has become an increasing threat in the UK, probably because of the introduction of more susceptible varieties, favourable weather supporting sporulation in spring and spread of Alternaria solani isolates less sensitive to strobilurin fungicides.

Caligula (fluopyram + prothioconazole) (0.5 L/ha) gives exceptional control of early blight and can be used in the crop up to three times, although you need to alternate a non-SDHI product after the second application.

It doesn’t give control of late blight so mix or sequence with a late blight-active product where necessary.

4. Third aphicide available if required for virus yellows in sugar beet

The beet industry has successfully applied for the emergency approval of Movento (spirotetramat) to control peach-potato aphids that transmit virus yellows in sugar beet, albeit with some significant restrictions.

First – this application is only for application to non-Cruiser (thiamethoxam) treated crops (eg ones that haven’t had a neonicotinoid seed dressing). Second, it can only be used as the third insecticide spray in the programme, after Tepekki / Afinto (both flonicamid) and Insyst (acetamiprid) have been applied to crops.

It should also, of course, only be used if the threshold of one wingless aphid per four plants up to the 12 true leaf growth stage has been breached, or one wingless aphid per plant from 12-16 true leaves.

Rapid knockdown of aphids should not be expected because of the how it works. Good coverage of older leaves is required as it won’t move from new to old leaves, but it will move to growing points.

While on sugar beet, just a reminder that if you have bought stock of Escolta (cyproconazole + trifloxystrobin) before its last sales date last autumn, it must be used up by the end of November. My advice would be to use it as the first fungicide spray in July at the onset of disease symptoms.

5. Carefully time oilseed rape desiccation

Desiccation of oilseed rape by Roundup (glyphosate) is a useful tool to help even up the ripening of crops making it easier to harvest. Weedy and thin crops should take the priority.

It’s important to get the timing right – if you go too early you can limit yield, oil content, and increase the number of red seeds, which can lead to rejections.

The best way to gauge this is to walk across the field taking around 20 pods from the middle of racemes. When two-thirds of the seeds in the pods have turned from green to brown, in at least 15 of the pods, the crop is at the right stage for desiccation – around 30% moisture content.

Don’t treat any crops that you’re going to use for seed – the last thing you want is to limit seed viability, and remember there is a statutory 14 day harvest interval.

6. Consider whether to use harvest management for cereals

In East Anglia most growers will let cereals ripen naturally, and maximise the length of time there is green leaf adding yield.

But if you have weedy crops that make it difficult to combine, it can be useful to apply glyphosate to tidy those up and make combining more efficient. Weeds that are green, healthy and actively growing will be easier to control, and match dose to the weed species.

Again, timing is critical – under 30% moisture content. The thumbnail test is a good assessment – if you put your nail into the grain and it holds on 20 grains collected from the centre of ears from various areas of the crop, it should be at or below 30% moisture content, although it is worth checking with a moisture meter.

There is a seven day statutory harvest interval in cereal crops, although it might take up to 14 days in wheat.

7. Think about burning off any bad infestations of grassweeds

Not an easy one to contemplate when grain prices are as high as they are currently, but any extremely bad infestations of grassweeds should at least be considered for burn off with glyphosate to limit seed return for future years.

For grassweeds like black-grass, that’s going to need doing as soon as possible in June, before any viable seed is set.

If you are going to do it, digital technology can help identify the parts of field with extra weed biomass from satellite imagery, which should be ground-truthed. Our Climate FieldView platform can then create application maps that calculate the exact quantity of glyphosate required, and if loaded into a sprayer with section or individual nozzle control make applications easy and accurate.