As autumn drilling follows a very wet period, slugs and their management should be a major consideration for wheat growers this autumn.
“The wet weather in late July through August and into early September will have been very favourable for slugs,” says Dr David Glen of Styloma Research.
“The main pest species, the grey field slug (Deroceras reticulatum) breeds rapidly when weather is wet at this time, so there will be lots of small juveniles ready to attack autumn sown crops. Weight for weight they tend to kill more wheat seeds than larger individuals which find it harder to move through the seedbed,” advises Dr Glen. “The damage risk also depends on the weather from now on, further rainfall will affect slug activity and survival together with the ability of farmers to produce fine, firm seedbeds.”
Slugs are a concern for Philip Huxtable, Director of Arable Production of the JSR Farming Group based at Southburn, near Driffield, E Yorks. Along with spring crops and 400 ha of environmental schemes they grow over 2800 ha of autumn sown crops. As a LEAF demonstration farm they take great care to ensure that they minimise the environmental impact of their farming operation. “At JSR we take a managed approach to slug control to ensure we stay within the metaldehyde stewardship guidelines,” he says. “The moisture is a bonus as far as getting crops away, but the slug risk needs to be managed.
“Despite the wet weather and the consequential lack of dust clouds behind the drill, we are achieving good seedbeds at the moment. Fine seedbeds help to inhibit slug movement and, along with the use of Redigo Deter (prothioconazole + clothianidin), allow the crop to get off to a good fast establishment. We use Redigo Deter on all our wheat and barley to help control a range of pests and diseases, especially BYDV and grain hollowing by slugs in wheat. Its use also helps us to manage our heavy autumn workload, as it reduces the number of times we spray or apply slug pellets.
“Once the crop is established, we set up traps to monitor slug activity and treat with pellets as appropriate, switching products if necessary to ensure we stay within metaldehyde use guidelines.”
Peter Stacey of Bayer CropScience confirms that prevention of grain hollowing of wheat by slugs is one of the many reasons that Redigo Deter is a popular choice for both early and later sown crops. “The later drilled crops can be just as much at risk of damage from pests and diseases as early drilled first wheats and the slower growth means any attack can cause greater damage than for fast-growing, earlier sown crops.”