DAERA Management Notes: Crops

Cereals: The period between harvest and drilling next season's crop provides a great opportunity to get on top of weed, pest and disease problems.

Thursday, 1st September 2016, 12:00 pm

Careful planning now gives the next crop a clean sheet hopefully making management later in the growing season more straightforward.

Slug monitoring

After another wet summer slug numbers are likely to be high this autumn. Assess slug numbers by trapping using a tea tray sized cover with suitable bait such as layers mash underneath. Don’t use slug pellets as the high concentration of pellets may poison wildlife or pets. Leave overnight and check traps for slugs the next day. This will give an indication of the risk level to the new crop and give time to plan the control strategy.

Details of thresholds at which potential slug damage is likely to occur in various crops and treatment options are available on the DAERA website (www.daera-ni.gov.uk). Follow links; crops and horticulture, combinable crops and select slug control.

Aphid monitoring and virus control

AFBI cereal aphid monitoring has commenced. August results showed winged aphid numbers were significantly higher at the beginning of this year’s migration period than the 15 year average, an early signal there could be a high occurrence of Barley Yellow Dwarf Virus (BYDV) this autumn. Taking action now to control virus carrying aphids is crucial to reduce the cereal virus risk. In fields with weedy stubble or a large number of volunteer cereal plants, this ‘green bridge’ should be destroyed to reduce the chance of infection from non-winged aphids. Desiccate seven to ten days before ploughing and at least 14 days before sowing.

Another option is insecticide seed treatment, for example Redigo Deter which protects emerging seedlings from BYDV in the weeks immediately after sowing. Seed treatment is a great insurance policy when weather hampers an aphicide application post emergence, protecting crops against both non-winged and winged aphids.

Aphid numbers, along with control measures, are posted weekly on the Barley Yellow Dwarf Virus control page on the combinable crops section of the DAERA website.

Stale seedbeds for weed control

Difficult weather conditions during the past growing season meant many growers found herbicides alone struggled to give satisfactory grass weed control. Where weeds are getting out of control consider an integrated approach using stale seedbeds. For most grasses, including sterile and great brome, aim to lightly cultivate as soon as possible after harvest. This encourages a flush of weed seed to germinate which can be burnt off before ploughing and drilling. If meadow, rye or soft brome is the main problem best results are achieved if seeds are left to ripen for three to four weeks before cultivation for a stale seedbed. If this does not allow sufficient time to establish a winter crop consider a spring crop which allows a longer window to get on top of severe grass weed problems.

Variety selection and seed treatment

With current margins tight the temptation to reduce input costs has to be carefully balanced against the potential loss in yield. As demonstrated by AFBI’s Dr Lisa Black at recent variety trials workshops, new varieties particularly in winter wheat offer a significant step up in disease control. Selecting the right variety now is a useful way to maintain yield without additional fungicide spend through next spring. Good varietal resistance to disease also offers insurance as disease resistance to fungicides becomes more prevalent. For further details on cereal seed and variety test results, see http://www.afbini.gov.uk/articles/seed-and-variety-testing-cereal.

Place seed orders early since choices will become fewer as the drilling season progresses.


Desiccation timing

Regular trial digs indicate when tuber size has reached market specification, allowing desiccation to be timed accordingly. Maintain blight spray programmes until after haulm desiccation to avoid late blight developing. Check at regular intervals for full skin set before starting harvest.

Store and equipment preparation

Thorough store and equipment cleaning is one of the most effective ways to avoid carryover of disease from last year. Ideally vacuum stores out to prevent the spread of dust and disinfect once clean. For best results thoroughly wash and disinfect boxes, harvesters, trailers and grading equipment.