Tree Pests and Diseases

Earl of Home Excerpts

Thursday 13th February 2020 Lords Chamber

[The Earl of Home (Con)]

My Lords, I thank the noble and learned Lord, Lord Hope, and the noble Earl, Lord Kinnoull, for introducing this debate. It is very timely indeed. I declare an interest in that I am a director of a farming company and a founder member of the National Forest Company, which was set up by that wonderful man Derek Barber.

It was only when I started to look at the various types of diseases that I realised how much Defra was involved in. Is it, perhaps, too widely spread? Should there be a bit more concentration? Or perhaps an easier way would be just to have more money.

I will concentrate on the prevention rather than the cure of these diseases. Several speakers here are much more experienced than I am in looking at these diseases. Yes, we can blame deer for quite a lot of damage in my part of the world; it is only the red deer, and if you get the right red deer and kill that, the trees will not be damaged. People exaggerate the amount of damage that deer do, and by more than one of them.

It is also popular to blame squirrels for a lot of damage that they do to oaks. I saw it myself when the oak trees became about 15 years old and the squirrels ring-barked them very effectively, which eventually killed them. It is, however, possible—but expensive—to eradicate almost all grey squirrels. In fact, it was done in my part of the world, in the south of Scotland, where we got rid of almost all the grey squirrels through a Scottish Government scheme of giving traps and monetary incentives to a group of landowners in the south-east of the country. That did not work, for three reasons. First, there were no reds within easy reach to get to and populate the place, so there was a vacuum. Secondly, it was not possible to import reds from elsewhere, because there was no surplus of reds anywhere. Thirdly, the scheme did not last long enough, so the greys came back in, as the Scottish Government had run out of money. But it can be done. After it finished, it took four years for the middle of the scheme to be reinfected by grey squirrels. So, at some expense, it can work.

The British public on the whole do not realise quite how destructive grey squirrels can be, and it would be helpful if the Government could in some way sponsor programmes and information to educate the person in the street on the harm that they do. Making it illegal to feed squirrels in the same way as was done for pigeons in Trafalgar Square might be considered, although I am not sure that it is practical. It might also be helpful if people knew that grey squirrels are extremely good to eat. I have eaten them but, to my mind, the best place for a grey squirrel is in one cage in London Zoo and nowhere else.

We are never going to stop completely the impact of disease-bearing organisms, so it is essential that we develop trees that are resistant to whatever problem is affecting them. The programme to breed hybrid elms has on the whole been quite successful; there is an avenue of such trees near Windsor racecourse that are so far very healthy. They are only about 10 years old, so we wait with some trepidation to see what happens as they get a bit older. Many splendid organisations are involved as well. Action Oak is supported by both Defra and the Scottish, Northern Ireland and Welsh Governments, while the Future Trees Trust is doing sterling work on ash dieback, as has already been mentioned, and on whether, through grafting or other methods, some ash trees may be saved, as they have very different DNA themselves.

The noble Earl, Lord Devon, mentioned chestnuts. Briefly, on chestnut tree canker, from which I have suffered, there is currently no chemical cure. Work is being done in America, but unfortunately it is not receiving either state or federal support. We ought to consider how we can do that research ourselves here. At home, we have looked at some ways of alleviating the problem of horse chestnut disease. You can do it by cutting out the clumps and leaving only individual trees, and so far it does not seem to have spread more than about 300 yards to any individual trees. That may be worth thinking about.

However, all these are temporary measures and, as other noble Lords have said, I hope that the Government will continue to give great support to those people working on all tree diseases.