Farming News - Target slug pellets carefully in potato crops this summer
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Target slug pellets carefully in potato crops this summer
Potato Council soils and water specialist, Chris Steele says that although the seasonal threat of slugs in potato crops is relatively low at the moment, due mainly to the dry conditions that have affected mainly eastern parts of the country, a lesson can be learned from last year.
“Last season was also relatively dry up until August, but then there was a lot of rain suddenly and the slugs quickly came up to the surface and attacked crops,” he says.
Mr Steele advises growers to get bait traps out in the fields immediately to monitor slug numbers throughout the season and be ready to act fast with a pellet application if threshold levels are reached.
“Growers should adhere to ‘good agricultural practice’ by targeting slug pellets according to where and when they are required, rather than applying the majority of pellets in July,” he explains.
“Additionally, by monitoring the pest carefully through trapping, growers and agronomists will be able to identify what type of slug pest they are up against,” continues Mr Steele. “Different species of slugs can come into the crop from the field edge, or they can come from the middle of the field, and a knowledge of this will again mean more effective targeting of product,” he points out.
Following stewardship guidelines is key when applying slug pellets to potato crops, says Mr Steele. “We know that the pressure is on to keep metaldehyde use to a minimum to reduce levels being found in water, and we don’t want to give anyone the excuse to take it away,” he adds.
Chiltern Farm Chemicals managing director, Philip Tavener suggests that potato growers should pay particular attention this season to maximum permitted metaldehyde application limits, some of which are now set by the CRD (Chemicals Regulation Directorate).
“A recent survey carried out on behalf of the Metaldehyde Stewardship Group (MSG) highlighted a lack of farmer understanding of both single, and yearly application limits for metaldehyde, and this could lead to restricted use of slug pellets later on in the season,” he points out.
Mr Tavener explains that the maximum permitted single dose application of metaldehyde is 210g ai/ha, and the legal maximum permitted yearly dose (of which only 210g ai/ha can be applied during the autumn), is 700g ai/ha.
BASIS advisers are reminded that, where possible, they should reduce this rate of 210g ai/ha to 160g ai/ha, he adds.
“When applying slug pellets to potatoes, growers should be aware that only 490g ai/ha metaldehyde (e.g. 2 x 7kg/ha of 3% pellets) can be applied during the summer if the maximum autumn application in the following crop is to remain as an option.”
He suggests that Chiltern’s range of Metamax and Wet Process slug pellets, which are CRD approved for use containing only 1.5% metaldehyde, continue to provide growers with a full range of application options.
“This means that even in high risk situations in potatoes, our pellet brands such as Allure and Attract can be applied up to 4 times in the potato crop, at the approved rate of 7.5kg/ha (112.5g ai/ha), while still allowing for a full dose rate in the following crop.”
Where slug numbers are lower, he recommends that rates can be reduced to 5kg/ha (75g ai/ha), providing up to 40 pellets per sq m, and allowing up to 6 applications per season in potatoes alone.
With an extremely dry start to the year, Mr Tavener urges growers to be particularly careful when applying slug pellets this season when irrigating in order to avoid an increased risk of field run-off and potential contamination of watercourses.