Farmers Weekly Interactive

Spud Special: Look out for little potato disorder

At the time of writing planting is still not complete in some areas, with some ware in Lancashire and some seed in Yorkshire remaining. Emergence is and has been rapid, within two weeks in some cases. Being able to travel with the sprayer to apply pre-emergence herbicides, particularly with recent heavy rainfall, has proved difficult.

Most crops that have recently emerged seem to be developing rapidly with small canopies and flower buds visible within a few weeks. Sunshine is needed to push a lot of these crops on, with some very pale foliage characteristics evident, and it is desperately needed to help early crops in Cheshire to bulk.

Arcade Little Potato Disorder

This year I have observed little potato disorder in a number of varieties that I have not seen it in before. Of course it is well known that varieties such as Pentland Dell and Sagitta are susceptible and growers can manage seed and planting conditions accordingly. However, I have also seen little potato disorder in Arcade, Cabaret and Premiere this year. As a result some seed tubers will never emerge, however some will, but there is likely to be a huge variation in tuber size distribution, dry matter and maturity.



As seed crops emerge my attention will be drawn to aphid control and minimising the spread of virus. The control of persistent virus such as potato leaf roll is relatively easy as aphids need to feed for a period of time to transmit the virus which also allows the uptake of aphicides such as Actara, Biscaya, Teppeki and Incyst.

However, the challenge is to prevent the transmission of non-persistent viruses such as potato virus Y (PVY) and potato virus A (PVA), which can be transmitted within 30 seconds of probing as the virus is carried in the mouth parts of the aphid. Therefore pyrethroids such as Hallmark Zeon and Sumi Alpha are best, as they offer some repellent activity as well as rapid knock down. 

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