If you remember the book/film then, not quite - but almost. Anyone who's a serious gardener (as opposed to someone who just likes to sit in their garden) will be horrified if they come across the worst weed in the world. No, not couch grass, bindweed, ground elder or mare's tail - but Japanese knotweed. This triffid of a plant spreads rapidly and is really difficult to control with weedkillers - although after lots of research on how best to apply weedkillers to get the best results, a couple of manufacturers do now provide glyphosate in a Japanese knotweed-unfriendly format.
However, there has been some other research that has yielded a novel control method, but it is causing massive outrage with some people at the moment. And that's using biological control to reduce its growth and vigour. Now I'm a big fan of biological control - I've used it in my greenhouse to eradicate whitefly, but it is expensive to use and all the environmental factors have to be right for it to work. But this particular biological control involves releasing an insect into the wild to control knotweed in the countryside and some people think it'll breed out of control and destroy our native flora. I've seen some of the research results and I believe it to be OK. But what do you think? Here's a round-up of what's happened.
The insect (a psyllid or sucker by the name of Aphalara itadori) is the result of 15 years' of research. It has been tested against around 90 species of native plants, on which it didn't survive, so it seems that Jk is its only food source and the only thing it feeds on. CABI, the organisation that carried out the research, is probably the world expert on biological control and their methods are accepted around the world. It would seem, then, that this psyllid is unlikely to pose any threat. During the research around 150 other organisms were tried and rejected as they could possibly feed on other plants; rejection happened when there was just one instance of an insect developing through to an adult on a native plant.
SEXIST TREE VALUATION ROCKS NATION
15 years ago
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It's proving to be an interesting debate. Just a couple of observations:
ReplyDeleteIn the case of your whitefly control, you're releasing it into a confined space, not outside.
They do attack other members of the knotweed family, though of course whether that's good or bad as they're also non-native plants is another debate we could have.
And didn't CABI say it's OK to unleash the cane toad in Australia?
I could be wrong on the last point as to who did the research, but my point re research and what actually happens out there still means we need to err on the side of caution in my view.
Ooops that's 3 not a couple ;)
Nice to see you blogging a bit more often :)
VP, thanks for your comments.
ReplyDeleteAll three of your points are, of course, very valid - and I agree that messing about with nature can cause all sorts of problems.
And let's not forget that gardening isn't very natural either - if it was we'd only be growing wildflowers in our gardens!
Quite right Geoff. And what exactly's wild is up for debate too, as I've seen species introduced by the Romans described as native!
ReplyDeleteVP, don't get me started on that one...!
ReplyDeleteBut we do have to thank the Romans for lots of things. Not least that if it wasn't for them the only vegetables we'd have in our diet would be nettles and seakale! I know there are others, but you know what I mean.