Good morning - it's winter, we´re going to prune our two year old trees (from the trunk upwards what is necessary) Some people advise us to apply a copper solution after pruning, others don't - what is your advice, experience?
Christa

Christa,

Spraying with cooper after pruning serves only to protect the trees from infection with Pseudomonas savastanoi pv savastanoi. Since you are in Uruguay I thing you don’t have to worry about this disease because the pathogen isn’t present.

Cheers,

João

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João Correia
Cascais - Portugal
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msn: jorgegranja@yahoo.co.uk

skype: JoaoJCorreia

thank you JOao for your prompt answer. i was just wondering if in humid weather like ours, it is valid not to spray copper after pruning - as far as I know, Portugal, Spain, is very dry?

It’s not that it’s drier; Lisbon has more or less the same rainfall as Montevideo. The main difference is the rain distribution, in the Mediterranean climates it rains mainly during the cold season, while in a sub-tropical climate like yours I believe it rains mainly during the hot season. So during pruning it will probably be damper here.

But has I said before, cooper after pruning serves only to prevent P. savastanoi pv. savastanoi infection (olive knot disease). I believe this parasite isn’t present in Uruguay, I think it only exists in the Mediterranean and California. If you want to be sure check with your local agriculture services.

João

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João Correia
Cascais - Portugal
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msn: jorgegranja@yahoo.co.uk

skype: JoaoJCorreia

thank you! we have rain in mainly in winter, but also in summer - its quite irregular. I've checked with INIA our agricultrue service, and they tell me that
we do have this disease in Urguay, although not common. So I have finally sprayed with "caldo bordoles".
regards- xta

Well you probably wasted your "caldo bordoles" ("calda bordalesa" in Portuguese ).
Olive knot is not a very dangerous disease, because it's not very infective and doesn’t make notable damages in the production.
When one accesses the danger posed by this disease one should consider several factors:

* Olive cultivar, some cultivars are more prone to olive knot infection that others ("Frantoio" is very sensible wile "Leccino" is relatively resistant);

* the occurrence of hailstorms that will damage the branches creating the opportunity for infection;

* the combined infection of olive knot with Spilocea oleaginea (Peacock spot). Spilocea will make the leaves fall and olive knot will infect the small wounds left by fallen leaves.

These are in my opinion the main aspects you should take in consideration.

Also, how far away is your olive grove from the nearest one? Because if it’s very far away (a pair of Km) and olive knot isn’t present in your grove you can relax.

In my opinion, you should re-check with INIA if the Pseudomonas savastanoi patovar present in Uruguay is the “savastanoi”, because in my opinion it probably will be “neri” that only affects the ornamental shrub “Nerium oleander”.

Regards,

__________________
João Correia
Cascais - Portugal
____________________________________________
msn: jorgegranja@yahoo.co.uk

skype: JoaoJCorreia