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12 messages
30/08/2013 at 08:10

I have a victoria plum tree about 6 years old. About half of the 200 or so plums have been attacked by Brown Rot. A lot of the rest have black around the stone and pink grubs.What is it? I shall make sure they are all disposed in the bin but can I prevent it next year, ideally organically. I estimate that I have lost about 80% of the crop with the two problems.

30/08/2013 at 09:31

Plum moth. it has little pink grubs eating the fruit from the inside. You can spray, but if you  don't fancy that, you can put up plum moth pheromone traps. they don't work completely, but it does cut it down.  Victorias usually have such a heavy crop, you can sacrifice a few

30/08/2013 at 10:11

I have been trying to find out what to do about a similar problem and it may be the same issue though looking on the web seems to show up all sorts of issues.

I have a young Victoria plumb tree that I planetd last year and is yeilding it's first crop.  There are probably around 40-50 plumbs on the tree which a lot seem to look OK.  Few not looking so healthy.  Anyway, last night I very gently tugged at a few that looked rippened and about 8 in total came away easily and looked ready.  Of those 8 only 1 didn't have a brown discolouration around the pip with a single (what looks like white) worm in it.  I'm therefore assuming that the remainder of the fruit will be ruined.

I did spray the tree twice earlier in the season with neem oil as advised on a few sites as the previous year we did get a lot of white deposit on our fruit trees (later found out aphids).  There were still signs of it a little this year, but I sprayed and cleaned the tree so that all the white was removed.

My assumption is that the worm in the fruit is related to the aphids, so my questions are (a) does anyone know if my assumption is correct or is this likely to be something else and (b) how best to avoid this in the future as very disheartening.

Thanks,  Scott

30/08/2013 at 11:02

The worm in the fruit ends up as a moth. Definitely not aphids. I usually find that the earlier ripening ones have more damage. The later ones are ok. Just cut them in half to check, before you throw them all out.

Pheromone traps for plum moth are usually available in the garden centres in Spring.

30/08/2013 at 13:07

If the grub is white then it is more likely to be Plum sawfly than Plum moth. Just as bad though. As FB says they are nothing to do with aphids.

All you can do is to spray with a suitable insecticide about a week after the petals have fallen from the flowers.

01/09/2013 at 19:33

Berghill that is interesting I didn't know about plum sawfly just plum moth,  is the treatment the same for both? have spent the afternoon taking all  the Victoria plums from my tree and disposing of them most  had Red plum maggots in them so all had to go. 

Last year a few plums had the maggots so this year I took the precaution of spraying the whole tree as the instructions, applied glue bands and used pheromone traps can't think of any thing else to do. Please has anyone any other ideas? 

Will this mean I have to get rid of the tree altogether or might next year be better?

Would be grateful for any help or ideas Thanks GrandmaT

 

06/09/2013 at 09:09

Thanks Fidgetbones and all other comments, helpful and interesting.

I'm wondering if it's just a bad year for moths. Certainly I've seen more butterflies, wasps and bees in my garden thean I can recall in 40 years.

10/09/2013 at 09:35

Very interesting thread; thanks to all.  Esp Grandma T, who seems to have tried all the preventatives and yet still has the issue.

I bought a mature Victoria plum tree two years ago, which had a house and garden thrown in free with it.  Seriously, the plum tree was a MAJOR selling point as I viewed the property when it was absolutely laden with perfect looking & tasting fruit.  I am such a Victoria addict that I just harvest straight from tree to mouth until I start to feel ill with indulgence.  Disgustuing, I know.  Anyway.....

First year I lived here all plums were perfect.  This year I have a fair few plums with worms.  I stand under the tree with a knife and bisect each fruit before eating it.  I want it to be a purely vegetarian experience.  Also, the harvest is so large that even after eating/cooking all that my family possibly can, I give away some of the harvest and even sell about half to the local greengrocer.

Perhaps the previous owner took better care of the tree than I.  He was an exceptional gardener (my main reason for buying the property) and he didn't say anything about pesticide or treatment, but...?  How guilty I now feel.  Am I worthy of caring for such a treasure?

10/09/2013 at 15:15

This looks interesting (at least to me):

http://www.gardenaction.co.uk/techniques/pests/plum_sawfly.htm

Myabe I will try to turn the soil and expose the pupae for a birdy feast.  I like the theory.

10/09/2013 at 22:51

The maggot causes the plum to soften early and fall from the tree before the healthy plums that remain on the tree have ripened. So as somebody has already said the later plums will be maggot free.

I control the problem by collecting all the fallen plums and destroy the worst affected. It doesn't stop the problem completely but certainly reduces it. If you cut the plum in half and remove the maggot you can scrape the brown out and use the plums for cooking if you only have a small crop. Otherwise just wait a bit until the later ones soften. They will taste better too as the early soft ones don't taste as sweet as the later ones. The maggot causes a false ripening.

If you are going to collect the early affected ones it does mean that you have to keep the grass very short under the tree so that you can inspect the tree daily and gather the culprits when they have fallen.

j t
22/09/2013 at 13:16

I have been trying to grow some plums, including Victoria in Italy, where I live.  Over the last three years, as the trees got established, I have not had a single plum to eat, though the trees have set many. Finally the problem was identified as the Plum Fruit Moth. I was advised the problem was not soluble for the private gardener; If you look at the measures recommended by a number of fruit-growing States in the USA you will understand why. They have the problem,shared with Italy, that there may be several generations of the moth in a single summer.

My neighbour tells me he cut down all his plum tree years ago, because he never got any fruit from them

So I decided to try my luck with netting two of the trees a Victoria and a Reine Claude Yellow.

It was difficult to get info re the size of the moth so I tried two different nets.

On the Reine Claude I used fleece over a number of twigs and branches bearing fruit, leaving other fruit unprotected.

On the Victoria I covered the whole tree, about 2 1/2 m tall, with a net made of green debris netting.  For this tree I also covered the ground within the net with layers of black plastic tied tightly round the trunk, as all previously fallen fruit had been left where they lay..

Both trials were a success.  In the case of the Reine Claude the netted fruit matured without any infection.  None of the un-netted fruit matured, all falling off before maturity.

In the case of the Victoria the tree suffered from drought in July, losing many of its leaves, and when I began to water it many of the fruit split and then dropped off. However none of the fallen fruit showed signs of infection. This month (September) the remaining fruit on the Victoria has been ripening satisfactorily, with none of the picked fruit showing any signs of infection.  The fruit is drier in texture than I would expect from a Victoria plum in England, so I will have to see if that can be cured by watering, or if it is just a result of the summer heat.

I have posted pics of the two trees netted:- DSC02021s.JPG
http://www38.zippyshare.com/v/71048748/file.html

DSC02024s.JPG
http://www39.zippyshare.com/v/79139555/file.html

25/09/2013 at 08:55

I have no fruit in the top of the tree. There was plenty of blossom. I am putting this down to wood pigeon damage.

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