Re: Pittosporum tobira

Tim Longville wrote:
> 
> Here's an odd one. My variegated form of this grows like an express
> train and nothing could be more healthy and vigorous. But the type has
> 'something' up with it. Question is, what?
> 
> Leaves continually turn yellow and drop. Sometimes they twist before
> they drop. 
> Tim on the tropical Solway - well, almost: 85 and rising...

Tim
At least summer is finally doing its stuff and I rejoice with you. We
have just had our worst week of the winter with freezing winds, overcast
and almost continuous showers, but today the sun has at last re-emerged.
Actually  we do have one thing to rejoice about. Our North Island
ski-fields on Mt Ruapehu have languised all winter from lack of the
white stuff (never so reliable there as in the Southern Alps) but this
last week they have had a fine dump and yeasterday (saturday) saw a
crowd big enough to warm the hearts of the local operators, who were
facing the grim spectre of bankrupcy.

Three possible suggestions about your tree. Thrips, spider mites or some
small not very intrusive scale. I got quite a lot of yellowing on my
standard bay tree a couple of years ago and finally traced it to a scale
of such modest dimensions I had not even noticed it until it built up
its numbers. The thrips sound less likely, I admit, as they don't very
often cause yellowing, but more commonly turn leaves silvery or grey.
Mites, on the other hand do cause yellowing on some of their victims,
such as certain roses.

Anyway it might be worth inspecting the foliage with a hand lens.

Moira

-- 
Tony & Moira Ryan <theryans@xtra.co.nz>
Wainuiomata, 
New Zealand (astride the "Ring of Fire" in the SW Pacific).
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