Five helpful pieces of advice for East Anglian growers this September

Crop Progress

Harvest is pretty much complete in East Anglia, with very little having to go through the drier. Most growers have been happy with winter crop yields that have been generally above average, except on some of the lighter land.

Spring crops were more of a mixed bag, with yields dependent on soil type and how much rain they received and when.

Oilseed rape performance was quite dependent on how it established last autumn – yields have been average in the main, but the price was encouraging some growers to consider growing it again.

James’ agronomy tips for September

1. Choose vigorous oilseed rape varieties for September drilling

While more growers might have been considering growing oilseed rape again, drilling in August has been much more difficult than in the past two seasons with the dry weather.

Where areas have had some rain, some crops will have been drilled, but in Norfolk very little had been established by 20 August. If and when we get some rain no doubt growers will still be keen to drill the crop, as alternative break crops are limited. Maize this year has been difficult because of the dry, although if there is a reduction in the forecast 425-450k ha of oilseed rape there might be more maize in spring 2023. Another alternative in this area could be sugar beet where there is an increased beet price for the 2023-24 contract year.

As this is written, there is still a lot of oilseed rape to go in the ground, but it is still possible to achieve good crops of oilseed rape from early to mid-September drilled crops. Obviously sustained moisture availability will be crucial.

One other key to success will be to choose a variety with the vigour to jump out of the ground to get away from cabbage stem flea beetle. Our Dekalb range all have good autumn vigour, especially where drilled in early September. For later mid-September sowings DK Exsteel and the Clearfield variety DK Imove CL have ultra-rapid establishment and might be good choices.

Conserve moisture by avoiding unnecessary soil movement and rolling soon after drilling, which will also help get good seed to soil contact for germination. Starter fertilisers or organic manures can also help with fast emergence.

Don’t forget all Dekalb varieties this season are eligible for our Establishment Scheme. To be eligible crops have to be planted before 20 September, registered by 30 September, with claims needing to be made before 31 October.

2. Use stale seedbeds as first line of defence against grassweeds

With plenty of time between harvest and drilling of next season’s cereal crops there should be good opportunities for stale seedbeds this season, although obviously moisture is needed to get weed seeds to germinate.

Whether to cultivate or not will depend on the farm situation, but light cultivations can be useful to encourage seed to soil contact.

ADAS research suggests the dry, hot weather during black-grass maturation should mean low dormancy this season, and once moisture arrives germination should be quick.

For good integrated weed management, the Weed Resistance Action Group recommends no more than two applications of glyphosate to stubbles to avoid multiple repeat applications. If necessary, incorporate mechanical cultivation to take out any surviving weeds.

The correct dose is also important. For 2-3 leaf grassweeds use a minimum 540g ae/ha of glyphosate and 720g ae/ha when you’re targeting tillering sized plants.

Also optimise applications by not going too quickly – 10-12 km/h, boom heights of 50cm above the target and using the correct nozzles to target small plants.

The brand of glyphosate can also make a difference. In trials last year comparing Bayer branded Roundup and a generic competitor at the same rate there was a clear difference in performance across different grassweeds in our weed screen and when applied to stubbles

3. Look out for new option for weed control in winter barley

With winter barley drilling likely to start later this month, there is a new product to consider for pre-emergence grassweed control in Proclus (aclonifen). It’s a new mode of action in winter barley to be used in mix with Liberator (flufenacet + diflufenican) as in winter wheat.

One difference to be aware of is that the rate in winter barley is lower at 1.0 L/ha, compared with 1.4 L/ha in wheat. It will especially suit situations where black-grass and Italian ryegrass threaten.

Make sure the mix is applied pre-emergence of the crop, as in wheat, and the seed is drilled to a depth of at least 32mm. Ideally apply within 48 hours of drilling for best results. This season we won’t be supporting any additional tank mix partners in winter barley.

Where annual meadow grass and broadleaf weeds are the main threats in barley, alternative options of Alternator Met and Octavian Met (both flufenacet + diflufenican + metribuzin), which can be used up to 1.0 L/ha until the end of September could be used.

In winter wheat, delaying drilling until mid-October where there are difficult grassweeds is still agronomically sensible. But there will be wheat drilled in September and the same options as in winter barley are available, depending on weed targets. In wheat the Liberator + Proclus option has had very good feedback from those who have used it.

4. Watch out for Cercospora in sugar beet

Virtually all the sugar beet region has been under high pressure for Cercospora from the middle of August at some point, according to BBRO’s risk forecasting, which makes the approval of Caligula (fluopyram + prothioconazole) welcome as another option for controlling the disease along with rusts and mildew.

Cercospora is likely to be more of a risk in areas that have had more rainfall, while powdery mildew is more problematic in drier areas. Rust pressure so far has been reasonably low, but can be found. Caligula can be used from 1 September at 1.0 L/ha, and brings a SDHI active ingredient to the crop.

Applications of any fungicide should be at first signs of disease, but in wilted crops this can be problematic. Spraying early morning is one possible way crops will be upright and inner leaves turgid, and fungicides more effective.

5. Finish off potato blight programmes

Potatoes have also struggled with the lack of rainfall, especially unirrigated crops. Blight pressure has been low most of the season, but with cracked ridges tuber blight is a threat and the outlook can change quickly. With a lower yielding crop likely, protecting crops as they go into store should be worthwhile.

Infinito (fluopicolide + propamocarb) is a decent late season blight product with activity against both tuber and foliar blight. Keep spray intervals for seven days but use no more than four applications of Infinito during the season.