Archive Article: 1997/10/04
THE sugar beet disease rhizomania has been confirmed in Nottinghamshire last month. What can growers do to protect their crops from this soil-borne disease?
1THE news must come as a disappointment to all in the industry, but it is not unexpected. The Notts region has similar cropping patterns and soil types to those in the east, including root crops such as potatoes and carrots. Many fields are irrigated.
Notts growers shouldnt panic – remember, we have been living with rhizomania in the eastern region for some time. And although this is the first outbreak to be confirmed outside East Anglia, so far it is confined to just one field near Newark.
Beet from the infected area is being destroyed. As a precaution, uninfected beet from the same field will be processed at either Cantley or Ipswich factories, both of which have tidal discharge facilities.
For growers unlucky enough to find rhizomania on their farms, the consequences are not as alarming as they were before.
The containment policy has been relaxed. Infected fields must be taken out of beet production, which includes table and red beet. Seed potatoes and transplanted crops are also prohibited. But combinable crops, which do not involve soil movement, are permitted. Beet can be grown on other fields on the same farm.
For 1998 cropping, the rhizomania resistant variety Ballerina may be grown on farms where the disease has been confirmed. This variety slows the multiplication of the disease in the soil, although there is a small yield penalty compared with susceptible varieties. However, it may not be grown on infected fields.
The industry has agreed that for now, Ballerina should not be grown on farms where the disease has not been confirmed. This is because it could make it more difficult to track the spread of infection.
Growers should continue to practice good hygiene as a precaution. Soil should not be moved from farm to farm.
Dr Mike Armstrong,
British Sugar, Holmewood Hall, near Peterborough.
2SO FAR this season 10 new outbreaks on previously uninfected farms have been confirmed, including the one in Notts. There are also 14 "extension" outbreaks – sited on farms which have already had the disease confirmed on other fields.
This running total is lower than last year, when we saw outbreaks on 25 previously uninfected farms – a record number for the UK.
The disease seems to prefer light, sandy soils, although a significant number of sandy loams are now being included in the total.
Weather conditions play a role. Rhizomania is favoured by warm soil temperatures, particularly in the spring – which is what we had this last season. The wet June may also have encouraged the disease.
At present, the UK has official rhizomania-free status within Europe, along with Denmark, Sweden and Ireland. MAFF operates a containment and protection policy as a result. The UKs status comes up for review in 1999.
Dr Mike Asher,
IACR-Brooms Barn, Suffolk.