[DIGGER]

Hi All,

I am planning to grow potatoes on land that was previously used for cattle grazing, the soil appears to be good consisting of a layer of peaty soil about 8 inches deep and then below that it becomes sandier. My concern is that my crop may be attacked by insects such as eel worm etc. My Dad recently took on an allotment that hadn't been worked for some time and his potatoes were ruined by boring insects. I have heard about green manure crops helping to cure the problem but would appreciate some advice on this matter before I get started next year.

Digger, 

[smallholder in the city]

White mustard used as a green manure is supposed to help with eel worm. Apparently by confusing the eel worm to breed at the wrong time. However, mustard is related to brassicas so indiscriminate use can increase risk of club root.

Marigolds are also apparently a good companion plant to deter eel worms.

Garden Organic have following advice
Potato eelworm (Heterodera rostochiensis and Heterodera pallida)
Symptoms: This microscopic pest can survive in the soil for 20 years in the absence of any potato crop. It tends to be common on allotments, where potatoes are often grown without using a crop rotation.

Infected plants will tend to die back early, sometimes in patches, and yields will be reduced. Where soil is severely infested, growth and cropping may be minimal. To confirm the presence of eelworm, check in July/early August. Carefully expose the roots of a potato plant and look for pinhead sized white, yellow or brown cysts on the roots. A magnifying glass may help!

Two forms of potato cyst eelworm are commonly found - Heterodera rostochiensis, the golden eelworm, and Heterodera pallida, the white eelworm. It is very difficult for the amateur to identify which type is present. The only time it matters which type is present is when using resistant varieties; the majority are only resistant to the golden eelworm; a few to both.

Control:
Use certified seed to avoid introducing the pest.
Use a 4 year crop rotation; longer where eelworm is a problem. Tomatoes are also susceptible.
Pentland Javelin, Cara, Maris Piper, Nadine, Nicola, Kestrel, Swift, Sante and Valor, for example, are resistant to the golden eelworm. Kestrel and Sante must be the preferred choice as they also have some resistance to the white eelworm.
Use compost and composted manure to improved the soil.
No-dig growing can reduce the effects of eelworm on potatoes.   

[Sylvia]

I grew spuds on land that hadn't been tilled for years this year. My land is shaley clay and I had a good crop of sound potatoes. A tiny bit of scab on the Maris Pipers but that was all. I don't know whether the type of soil encouages wireworm or not. I grew mine on the"lazy bed" method.(still damn hard work though!)