Harry Barnett, crop production manager at Holkham Emerald With 80% of the potato land farmed by Holkham Emerald having a potato cyst nematode population of less than 5 eggs per gram of soil, the desire to ensure it remains low has led the company to apply Bayer’s new nematicide Velum Prime (fluopyram) this season.
Across 400 hectares that is in potatoes for only the second or third time, Holkham Emerald, a joint-venture between Holkham Estate and Emerald Crops, will treat about 70 hectares with Velum Prime to protect crops and control nematode populations.
“We don’t have a nematode issue per se, but we are not being complacent,” says Harry Barnett, crop production manager at Holkham Emerald.
Salad potatoes make up for about 75% of the crop with the remainder sown to ware crops, but it is in protecting the former that attracted Mr Barnett to Velum.
First, it is the absence of a restrictive harvest interval that otherwise precludes the use of conventional nematicides, and second, it was a combination of low application rate and the easiness of handling this enabled, but also the favourable profile.
Nematicides are only one part of the longer-term plan to control nematode populations which due to a history of carrot production on the estate means spraing is also a concern.
In the early years of the business the estate followed a six-year rotation, partly because the virgin nature of the land made it possible, but also because the financial pressures of establishing the enterprise made it necessary. Now, some 15 years since its inception and with the enterprise beginning to mature, the rotation is to be expanded to one-in-eight by 2021.
“As a salad grower quality is the principal concern and experience suggests that longer rotations support cleaner skins, but there is also the need to be confident that our activities are sustainable in the face of a changing political environment that wants to see less use of plant protection products of all sorts,” says Mr Barnett.
“Velum is part of an integrated approach to profitable crop production through good management of our natural resources. A balanced rotation is fundamental to this, and we seek to include two cover crops per rotation cycle, use resistant and/or tolerant varieties where they exist and only apply selected plant protection products where monitoring or field history indicates they are required,” he adds.