14 November 1997

Blackleg cloud over home potato seed

POORLY managed home-saved potato seed from blackleg-susceptible varieties could cause problems next season, warns a Lincs-based pre-packer.

Dry weather in August and good lifting conditions mean overall levels of Erwinia bacteria – the cause of blackleg – are not particularly high, says David Nelson of Branston Potatoes.

But disease development in next years crops depends very much on how seed is stored and handled, he advises.

Home-saved users switching to Estima from Cara and Romano, which may be handled quite roughly without causing too may problems, could be in for an unpleasant surprise as the latent disease develops, Dr Nelson suggests.

"A small period of bad handling can lead to major problems in the field. The first curing period is critical. But if you put tubers in the back of a damp shed and then knock the sprouts off in the spring even the cleanest seed will have blackleg."

Using once-grown seed causes quality and traceability uncertainties which supermarkets dislike, he adds. "Processing contracts dont permit farm-saved seed."

Packer Branston Potatoes got together three years ago with Anglian Produce and A &#42 Worth to form Pseedco, a firm which aims to improve seed quality for their ware grower customers.