State of plant health was good in 2007

6.6.2008

<div>New quarantine pests have not established themselves permanently in plant production, according to the Plant Protection Unit’s monitoring report for 2007, published by Evira. The trend in the state of plant health is affected by international trade, as many pests spread through foreign plants and other plant material.</div>

Horticulture

There is a great risk of the sweet potato whitefly permanently establishing itself in greenhouse production.  Permanent occurrences have so far been prevented through inspection and pest control. However, the situation has become more difficult each year, as in recent years increasing numbers of plant consignments of foreign origin contaminated with the sweet potato whitefly have been found. The sweet potato whitefly is found in poinsettia production and also nowadays in bedding plants, such as in the production of summer flowers.

There appears to be an increasing risk of sudden oak death spreading to production areas, as in 2007 the disease was found in three nurseries in rhododendron plants of foreign origin or the nursery’s own production. The number of occurrences of quarantine pests in other garden plant production was quite small. Of the quarantine pests, red core and fire blight have still not been encountered in Finland, nor has strawberry black spot occurred in any great numbers since 2005. The situation for 2008 will largely be affected by the health of plant materials imported from other EU countries.

Potato production

In potato production, there were slightly more occurrences of ring rot in 2007 than in the previous year. The origin of ring rot is usually impossible to trace. Ring rot spreads from farm to farm with consignments of potatoes for sale and with shared farm equipment. On a farm, the ring rot bacteria survives and causes latent infection in the farm saved seed and in potatoes that remain in the field over winter. Potato brown rot has not found in Finland.

Surveys carried out show that the yellow potato cyst nematode has mainly been found in Southern and Western Finland. In the main potato growing areas the potato cyst nematode situation has remained stable. It would appear that in the control of the potato cyst nematode, eradication  programme based on crop rotation and species selection are not sufficiently effective to destroy PCNs, as live PCNs are still being found in samples taken after nine years eradication programme  There have been no occurrences of white potato cyst nematode since 2004.

There have been no major occurrences of the Colorado potato beetle since 2002. What the situation will be in summer 2008 is, however, fully dependent on the summer weather conditions. There are already permanent occurrences of the Colorado potato beetle around 100 kilometres from Finland’s Eastern border, and strong airflows from the east and southeast could cause the beetle to spread.

Wooden packaging material

Each year a lot of wooden packaging material is imported to Finland from countries where the pine wood nematode occurs, these countries include the United States and China. Only a fraction of this material can be inspected. Imported wooden packaging materials continue to pose the risk of the pine wood nematode spreading to Finland. The requirements for heat treatment and markings in accordance with the international ISPM 15 standard, adopted in 2005, should prevent the spread of pine wood nematode through wooden packaging materials.  However, findings of the pine wood nematode after the adoption of the new standard show that the treatment requirements are either not always followed, or that the treatments are not sufficiently effective for destroying the pine wood nematode in timber.

Evira Plant Protection Unit’s monitoring report for 2007 (in Finnish, pdf, 612 kb)
www.evira.fi> Tilauspalvelut> Julkaisut> Eviran julkaisuja 2008> Eviran kasvinsuojeluyksikön valvontaraportti 2007

Further information:
Director Hannu Kukkonen, Evira, Plant Health Unit, tel. +358 20 77 25030
Senior Officer Paula Lilja, Evira, Plant Health Unit, tel. +358 20 77 25043

 

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