Powdery mildew

[AlvinD]

Can I ask Tony what is the aim of your survey?

[agg221]

The orchard I grew up on in the '80s regularly had a powdery mildew affecting the apples in late summer, but not the pears, plums or cherries. There was an insect that ate the tips out of the fresh shoots each year at about 3" long, so by the time they got going again it resulted in soft, sappy shoots much later than normal, equivalent to lammas growth in oak, and that's what was (and still is) regularly affected.

 

Alec

[David Humphries]

The orchard I grew up on in the '80s regularly had a powdery mildew affecting the apples in late summer, but not the pears, plums or cherries. There was an insect that ate the tips out of the fresh shoots each year at about 3" long, so by the time they got going again it resulted in soft, sappy shoots much later than normal, equivalent to lammas growth in oak, and that's what was (and still is) regularly affected.

 

Alec

 

Hello Alec

 

do the pears, plums & cherries have any mildew at all now ? (both in the orchard you grew up around & others that you visit)

 

 

 

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[agg221]

Hi David, I was down there a couple of weeks ago and no sign then, except on the apples. I was picking and pruning the plums so had a good look, less specifically looking at the apples. By this stage, the leaves on the cherries are beginning to look tired and just ready to start colouring, so it's less surprising that they aren't affected. It's also notable that the (extremely irritating but unidentified) insect is, it seems to like pears and apples most. The pears rarely respond with much growth, the apples do. I therefore think there may be a link between fresh, young shoots, time of year and weather in the prevalence of the mildew - the other orchard species just don't bring them together in the same way.

 

Alec

[Tony Croft aka hamadryad]

Can I ask Tony what is the aim of your survey?

 

bit of a derail but as you asked!

 

The intention of the survey is to provide a large data set that will become part of a PHD thesis on heart rot fungi of Oak species native to the U.K, with particular emphasis on the brown rots. Oaks are quite unusual in respect of the number of brown rot fungi they are host to, only around 6% of fungi are known to be brown rots and of those most are limited to the Gymnosperms (Conifers).

The U.K’s native Oaks have at least four major brown rotting Basidiomycete associations, one of those being species specific in its host range- Piptoporus quercinus (right-note buckling at base also site of sporocarps) others, Daedalea quercina, Fistulina hepatica and Laetiporus sulphureus are less host limited with L. sulphureus being the most broadly hosted fungi in this group, and F. hepatica being somewhat more limited in range. Field observations have indicated the changes in morphology associated with F. hepatica are the most pronounced and unusual, maybe even mutually beneficial within Oaks, but also potentially very similar within the host Castanea sativa.

There are some white rotting Basidiomycetes to be included in the study to ensure the data is as wide ranging and as in depth as possible, even trees that show no signs of fungal colonisation will be included in the survey (control) which will be in the region of 1000-5000 trees.

There are several white rotting Basidiomycetes that also have a high degree of influence on the morphology of oaks many are Ganoderma Sp, G. lucidum, G. australe, G. lipsiense and G. resinaceum. Ganoderma pfeifferi is known to colonise oaks, however this is a very rarely colonised host, with Fagus sylvatica (European beech) being a far more commonly associated species. Ganoderma carnosum is as yet only known to host on Taxus bacatta (Yew) in the United Kingdom.

Of most interest in the white rot group is Inonotus dryadeus, the oak bracket (left) though not host specific in range, rarely associated with other hosts and is particularly under recorded and documented in Oak ecology. That in itself is reason enough to include it, but it also has a very specific “Body language” (Claus Mattheck) that is one of the most commonly associated changes in Oak morphology due to a fungal colonisation. It is therefore vital to include it within the survey.

There is a risk in trying to take in too much data within the survey methodology, and making this survey difficult to complete, but equally there is as much danger in limitations, not having a broad enough overview of host/fungi and control samples to illustrate adequately the influence of host/fungi interactions and influences.

Other fungi are naturally going to be present and will be included in a final additional section to each recorded tree under the heading General fungi, this may seem unnecessary, but again when the data is under analysis these may yield interesting insights into Oak ecology not yet considered. Again it is field observations that have highlighted an interaction with Colybia fusipes (right) and this fungi will be included specifically for it is expected that a link with AOD (Acute Oak Decline) will reveal itself when it is present in connection with crown (Foliage) and upper root crown cambium damage or dysfunction. Armillaria is also expected to show in these circumstances and will also be included in data, noting both C. fusipes and Armilaria sp present or absent.

Field observations have also indicated a link between main stem failures in oak populations and dual colonisation via the brown rotting fungi F. hepatica and L. sulphureus, the analysis of the data may well help further indicate this and is from a prognosis and assessment for hazard rating perspective to be considered a vital part of the surveys purpose.

[David Humphries]

) I therefore think there may be a link between fresh, young shoots, time of year and weather in the prevalence of the mildew - Alec

 

If I remember correctly, I didn't note as much latter growth (lamas on oak particularly) last year,

due perhaps to it being such a heavy mast year.

Fruit & seed production more of a focus than additional photosynthetic material.

 

 

 

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[David Humphries]

bit of a derail but as you asked!.

 

.....and some

 

 

 

 

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[Tony Croft aka hamadryad]

.....and some

 

 

 

 

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[sloth]

Viburnum (tinus?)

[David Humphries]

Viburnum (tinus?)

 

bleedin everywhere innit

 

 

 

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