[Bodger]

We have  half a dozen eight or ten year old conference pear trees in the orchard. Last year, we had a bumper crop from them as they produced some delicious fruits. This year, they seem to be having a year off with only the odd pear or two on each tree. This rest year with pear trees, is not unusual apparently but this is.





I've had to cut quite a few branches like these out of them where the foliage has gone black and died. This isn't wind damage and the branches havent been damaged. Has anyone got an idea as to what my trees might be suffering from ? At the moment, I'm simply pruning out the affected branches and burning them. The rest of the tree seems healthy enough.








My damson trees have also gone from having loads of fruit last year to absolutely none this time around. On a happier note, our apple trees look set for a bumper crop.  

[lincspoacher]

The only thing that even vaguely fits what these trees are doing is Silver Leaf, but im not sure if its that.

[Trillium]

Its kind of hard to see on your pix, Bodger, but black leaves quite suddenly means you've got fire blight. It's a fungus carried on the wind from other infected trees upwind.

It's curable and must be controlled quickly. Cut off the infected branches as you've been doing, BUT you must dip the pruners/lopers into a jar of white vinegar after every cut. This way you don't spread any infection into fresh parts of the tree or into the cortex system. Burn the infected branches downwind of your own orchard.
To the remaining branches, you must spray a solution of one part white vinegar to 4 parts water. Spray leaf tops and bottoms to control the fungus which needs alkaline conditions to thrive. Also spray branches for stray spores. This won't hurt the leaves or bark at all and will quickly stop the fungus. If you see any small reappearances, do the same treatment and that should fix the trees for a long time.
Does it really work? Most certainly. Did my own pears and plums when they got infected and I've not had trouble since. I see now that many major ag services in the US are doing this (probably copied me as I've advocated this treatment for over 30 yrs).

As for crop yields, the trees have their own bumper yields determined by climatic factors and not by this fungus.

[Aunt Sally]

I was going to suggest fire blight too Trillium.

This is a USA fact sheet but the same would apply in UK Bodger.

[Bodger]

Someone on my home forum has found this. :shock:  :shock:  :shock:

 
http://www.defra.gov.uk/planth/pestnote/fireblight.pdf

It seems that its not curable. :cry:

If you read the defra link, what do you think that they mean by roguing ?

[Aunt Sally]

Not curable to my knowledge Bodger.

But make sure it is fire blight before doing anything drastic.  Prune out and burn any affected wood first !

[Bodger]

We havent had any new trees for about eight or ten years and there are no trees near us. I'll have to ring the number on the bottom of the defra report in the morning.

[Aunt Sally]

There's a number of other plants that it will affect as I recall.

[Aunt Sally]

Erwinia amylovora infects approximately
75 different species of plants, all in the family
Rosaceae. The hosts for this bacterium include apple,
blackberry, cotoneaster, crabapple, firethorn
(Pyracantha), hawthorn, Japanese or flowering
quince, mountain-ash, pear, quince, raspberry,
serviceberry, and spiraea.  The cultivated apple, pear,
and quince are the most seriously affected species, but
many ornamentals serve as overwintering hosts for
the bacterium and are important sources of new infections each year.

It can be spread by bees and rain

[Aunt Sally]

If you read the defra link, what do you think that they mean by roguing ?

To remove (diseased or abnormal specimens) from a group of plants of the same variety.

[Aunt Sally]

RHS has a good fact sheet:

http://www.rhs.org.uk/advice/profiles0700/fireblight.asp

The fact sheet says:

"Note: The Department for Environment, Food and Rural Affairs (DEFRA) no longer has to be notified of cases of fireblight that occur in garden situations in mainland Britain."
I don't know if your small orchard would be classed as a garden situation Bodger  

[lincspoacher]

AH yes well spotted. Fireblight is a USA problem, and the first case in the UK  wasnt noted until 1957, when it ripped through orchards in Kent, idk if its still a notifiable disease, though.

[Bodger]

Apparently not in a garden situation, unless you live in NI.

[gobs]

In a garden situation it can be controlled by what you are already doing, Bodger.

There are a few other diseases though that can cause die back. Brown rot or bacterial blossom blight can cause very similar symptoms. Additional symptoms as pictured in one of the links will be the give away.

[Country Bill]

We had loads of damsons last year,but none this year ,thanks to some late frosts.