Apple trees (pommiers) here in the Loire Valley are tortured by mistletoe (gui), which is a parasite. Le gui sends "roots" called suckers (suçoirs) down into the wood of apple tree branches and slowly sucks the sap and life out of its host. It's known to live on poplar, willow, locust, almond, linden, and certain pine trees as well. I'm talking about European mistletoe; there is also a variety of mistletoe that occurs only in North America. (Here's a link to a series of posts about mistletoe that I've done over the years, with photos of course.)
Here's what the big apple tree in our back yard looks like these days. It appears to be pretty old (but we don't know how old because we've only lived here for 16 years) and it is definitely in a weakened state. It's full of gui. It has lost several big branches over the past five years, and it is really lopsided and starting to lean. We figure we'll have to have it taken out before too much longer — or just wait for it to fall over. The trunk is badly split, and mushrooms grow around its base. That's a bad sign.
And here's a smaller apple tree out by our back gate, in front of the garden shed. It's also full of gui. From what I've read, one way to remove the gui is to "dig" it out by cutting the green part of the mistletoe plant off at the base and then scraping the surface of the wood it's been living on to try to remove all the suçoirs. The danger is that the scraping leaves a wound that can be attacked by other parasites and pests, or simply by humidity, rotting the wood and further stressing the tree.
This is a tree that has finally been killed by, I assume, a combination of gui and the weather. It grows on the far side of the pond that's outside our back gate. Monsieur Denis the elder, who owns or at least used to own most of the vineyards around our property, once old me that this was the tree that produced the very best pommes out of all the dozens of pommiers growing in and around the hamlet. He's handed the grape-growing business business off to his son and DIL now, and he has such debilitating mobility issues that we never see him out in the vineyard any more.
And finally, here's another solution to the gui problem: radical pruning. Our neighbor who lives most of the year in the Paris area just had a man over to prune the four or five apple trees that grow on her land. She told me in September, when she spent a few weeks in her house in the hamlet, that she was disappointed to see so few apples on the trees in 2018. I assume some professional told her that this is a way to try to bring the the trees and apples back. I hope it works.
I'll be curious to see how these trees fare in the spring. Maybe our trees need the same pruning. The strange thing is that we have two fairly large apple trees in our yard that have no gui growing in them at all. So I think certain varieties of apple are more susceptible than others. Another pommier, just outside our fence, is so full of gui that it can't possibly remain standing much longer. Our pear tree died last winter, but there was no gui in it. And our neighbors across the street lost two big pommiers last winter too.
I would have thought that the stresses on these trees were a)drought; b)fungi and c)mistletoe, very much in that order. Mistletoe doesn't take enough nutrient to harm a host tree, but it does make the tree more wind resistant, resulting in wind rock, which will disrupt the tree's ability to thrive. Many trees in the area are showing signs of slow decline due to a series of drought episodes. It only takes a few days to cause lasting damage, and if it's repeated often enough the tree will eventually die. The tree will also kill itself by the way it reacts to fungal invasion, closing down its own vascular system to try to block off the spread of the fungi. My guess about your neighbours apples would be that just at the key moment for pollinisation the weather conditions weren't right. Several of the chateaux locally got virtually no apples last year. The drastic prune will probably work quite well, although she'll sacrifice a year while the trees regrow.
ReplyDeleteI blame mild, wet winters more than hot, dry summers. Hot here is completely relative. The trees didn't die over the course of the summer but at the end of the winter. I think the mild winters encourage fungal invasion, and the damp goes hand in hand with that. I don't think the neighbor will be too worried about waiting for her trees to become productive again, since she spends very little time here. I think the sight of that completely dead tree — so dead that the mistletoe in it is also completely dead — moved her to try something to save her trees. Until we get back to cold, dry winters, if we ever do, I think a lot of trees will be giving up the ghost.
DeleteYou live in an area with so many fruit trees- those kings must have liked their pies and jams. I hope your trees recover somehow, but then again I remember how many apples they produce- it's quite a chore picking them all up!
ReplyDeleteI imagine that the four apple trees in our yard were planted when the house was built 50 or so years ago. It's interesting that the two apples trees in our yard that have no mistletoe in them, and seem resistant to it, are doing fine despite any drought episodes we've experienced or our wet, mild winters. And they've been productive. The had a lot of apples on them last year.
DeleteLook at these photos from Aug. 31, 2018.
DeleteYour thought that certain varieties are more susceptible sounds logical. Mushrooms around the base, as you say, are not a good indicator of the health of the tree.
ReplyDeleteSusan's comment above about the impact of drought is interesting. I wonder what the lifespan of these fruit trees is, of course you have no way of knowing when they were planted.
I'm not sure about the drought issues. We had so much rain in 2016... I'd have to look back at the numbers for 2017... We had a dry summer in 2018, but not all that dry. And not all that hot.
DeleteAccording to the MétéoFrance (national weather service here) web site, in the Saint-Aignan area we had 700 millimeters of rainfall in 2016, 700 in 2017, and 730 in 2018. 2015 was dry, with only 530 mm of rainfall. Funny how I don't remember that year being so dry.
DeleteNot sure about the lifespan of French trees, but I've seen apple trees around cellar holes in rural Maine still bearing after being abandoned decades ago, and the trees were likely planted well before the end of the 19th century. The apples are smaller and far from perfect, but the edible parts still quite tasty.
ReplyDeleteWe had so much rain this year that my little apple tree, a dwarf probably planted in the late '60s or early '70s, just fell over from the terribly saturated ground.
ReplyDelete