With potato planting underway in Scotland in dry but cold conditions, it’s been a more favourable start for the crop north of the Border than last year – but growers are being warned of the ‘sleeping giant’ that is PCN.
Agronomy firm Hutchinsons’ Cam Murray, its northern regional technical advisor, planting is ‘more normal’ in timing but because it has been so dry this spring, irrigation is already underway, though mainly for scab control. If dry weather continues, then it will be necessary to irrigate for crop establishment, warned Mr Murray.
He added that Scottish growers need to be more aware of the risk of PCN.  “I see Scotland as Lincolnshire was 15 years ago – PCN is our sleeping giant!
“Crop intervals are important for a number of key potato pathogens, with PCN No 1 on the list. We need to use precision soil sampling to accurately map the areas of infestation within a field and implement management strategies with the use of resistant varieties, specialist cover crops and nematicides should all be considered so this can be managed.”
Once potatoes are in the ground it is essential to get them up and meeting in the rows as quickly as possible, added his colleague, root crop technical manager, Darryl Shailes.
“In the drier south, irrigation is also often used for scab management early in the season, but it can be easy to underestimate the need for water early on, purely for canopy development. In dry years it can be a game-changer for crop establishment and maximising yield potential. So, even where scab management is not so crucial, early water can be.
“Growers in dry regions should consider irrigating as soon as the crop emerges in extreme situations, but don’t go too early as beds can be washed down.”
Rhizoctonia can be an issue in Scotland and he addded: “We are trying out in-furrow treatments with Amistar (azoxystrobin) for the first time this year for Rhizoctonia control, with a view to enhance the overall yield and to reduce the size variability across the tubers. “
The use of starter fertilisers, either placed with seed or worked into the soil before planting, can also help early crop establishment, Mr Shailes told The SF.
In Scotland while many growers split their nitrogen fertiliser, he said the jury was still out on the advantage from applying split doses of nitrogen fertiliser.