Forestry minister David Heath has blamed EU rules for threatening British plant health after it emerged that Government body the Forestry Commission imported more than 70,000 ash trees from overseas in 2009/10.
HTA business development director Tim Briercliffe said the Forestry Commission had "not been sensible" in planting imported ash in 2010/11 after the HTA had warned it in 2009 of the threat from Chalara.
The Forestry Commission said: "Before 2012 we had not been aware that there was a problem with Chalara infection in the UK ash trade or in imported plants.
"EU procurement rules were followed when we tendered our plant supply for restocking purposes in 2009 and, while we were advised that we could specify that the stock should be from certain UK seed provenances and be disease-free, we were also advised that we could not limit our tender invitation to UK suppliers."
Heath said: "I don't think you can blame the Forestry Commission or anyone else (for importing diseased ash) because we didn't know we had that level of infection on our doorstep. Now we do."
He added: "We need to think very carefully, setting out some basic preventive rules. With the EU it may be difficult, but we have to try. It's important we use our island status to prevent new diseases coming in. When we know a prevalent disease, we can avoid it. Some are wind-borne so are outside our control, but we don't want to physically import diseases.
"We can use overseas intelligence from our colleagues on the Continent. For instance, with the 42,000 infected plane trees on the Canal du Midi in France (with Ceratocystis fimbriata platani), it would not make much sense to import planes from France. But they can be imported at the moment, so we need to be increasingly cautious about this and to test with the EC what we can effectively do.
"We don't bring in animal diseases and have proper procedures, so it's hard to understand why it's different for plants."
But he said stopping imports was difficult: "When we will see something is a moving feast. We need to discuss with the trade and understand the implications of anything we bring in. There's a way to go with the EU before they are prepared to accept the logic of what we're talking about.
"We will work with Ireland and other EU island states perhaps so we may be able to prepare a more consensus approach to apply more pressure on the EU. We need to work with the EU with a degree of sensitivity because we're not in the business of stopping free trade."
C. fraxinea is not a "regulated" plant disease in European Union plant health law, which means that ash plants moved between member states are not subject to inspection. EU legislation allows member states to take national measures to prevent the entry and spread of pests and diseases not found on their territory, and the UK introduced such legislation for Great Britain on 29 October 2012. Northern Ireland and the Republic of Ireland have similar legislation in place.
Heath said exporting seedlings to grow on overseas should be stopped to prevent disease coming into the UK. He added: "I don't think it makes much sense to procure ash and then take it over to the Continent for growing and then returning it potentially with infection. It doesn't make a lot of sense especially as ash is a prolific species in this country."
Crowders managing director Simon Ellis (HW, 18 December 2012) said the Forestry Commission, Woodland Trust and Highways Agency could end the devastation caused by diseased imports by ordering in advance from British nurseries rather than importing.
Ash trees - Imports and disease
Over the past five years, around four per cent (70,400) of the 1,572,045 ash trees supplied to Forestry Commission England and Wales were imported, all in 2009/10. More than five million ash plants have been imported to the UK for forest and landscape planting since 2003, says Defra.
The Ash Dieback (Chalara fraxinea) disease has now spread to 309 sites since first being found in the UK in February 2012 - 17 nurseries, 132 recently planted sites and 160 established woodlands.
There are 22 sites managed by the Forestry Commission that have, or have had, C. fraxinea infection. There are 1,028,000 hectares of land under Forestry Commission management.