[David Bracey]

I have checked the Syngenta label.  If your product contains 100g of active ingredient per litre the rate of use is 25ml per 100litres.  Or

2.5ml per 10 litres.  Hope that helps. 

[hereistay]

It is Topas 200ew of Syngenta.
The label on my bottle says it is 200g/litre of penconazole, not 100g/litre...

Anyhow, David, are you expert with pistacia?
According to you it's ok if I leave the plants outside during winter season?
How much water should I give during winter?

[David Bracey]

If your product contains 200gl/ litre then you can cut the rate by half.  I am not a Pistachia expert just using common sense after a career in the plant protection business.
 
How much water will depend on how wet the winter is! I doubt if you will need to water very often however.

[hereistay]

Ok!
Thank you very much!

[hereistay]

I have a little problem!
Here where I live it's raining from 10th November.
I have these plants outside, I tried to cover them but they passed a day and half under the rain.
Yesterday, when rain stopped for a while I made additional drainage holes in the part that rests on the ground of the plant bags and I put them on perforated plastic containers, to facilitate drainage.
In the last days there were temperature anomalies for this period (>20°C) but the plants were allmost without leaves but I don't know if because of Septoria or because of dormancy.
When I put plants inside plant bags I made a soil mixture with about 150lt of universal soil, 50lt of volvanic lapilli (large grain), 25lt of expanded clay, a large bucket of sand.
Some of the bags are with volcanic lapilli and some with clay.
Is it well-drained enough?
In the bottom I put clay or lapilli or stones but not in all the bags.
The plastic sheet seems to do its work, in fact the stems of the plants are not wet.
Now it is not raining but a lot of rain is arriving according to weather forecast so I don't know what to do, if to leave them where they are or to move, maybe in the greenhouse.

This is the current situation:




Sorry if I am over topic!

[Alisdair]

Your soil mix sounds to me as if it has OK drainage. A very basic test is to pour water into the top of a plant pot. It should quickly drain away from the top. If water still stands in the top of the pot, you need more drainage.
Lifting the pots off the ground by using those plastic crates is a good idea. (Perhaps not if you expect hard frost though!)

[hereistay]

Hello everyone!
3 weeks ago my plants started to grow, but today I noticed the first spot of septoria! :/
So, I decided to give penconazole in the form of Topas 200 ew at 0.25ml/l.
Please tell me if my calculations are ok!
Topas 200ew has 200g/l of penconazole, so it means that every ml is 0.2g of penconazole, so 0.25ml has a total of 0.05g of penconazole.
I have now a product with 1,5g/l of penconazole, so it means that 1ml is 0.0015g of penconazole, so to have 0.05g I need of 33.333ml of the product.
So I need of 33.333ml in a liter of water to have the same 0.2ml/l with topas 200ew.
Is it correct?

ps: my perplexity is: why a ready-to-use fungicide has a so high concentration?

[David Bracey]

Correct, calculation!  I can only assume that the formulation you are using is the " commercial " formulation which makes measuring "easier" for the farmer?

[hereistay]

Today I sprayed penconazole!
A question, I made some graftings, one month ago, pistacia vera on my terebints, have I also to treat them with fungicide?

[hereistay]

In these days I read a lot of stuff and I found that septoria on pistacia is treated with:

-trifloxystrobin+tebuconazole
-25.2 % W/W Boscalid 12.8 % W/W Pyraclostrobin (is acommercial one)
-dithiocarbamates
-metconazole
-tebuconazole
-azoxystrobin
-chlorothalonil
-ciprodinil+fludioxonil
-propiconazole
-fluopyram+tubeconazole

According to you wich one is the best?

I used penconazole, but I know that all these other fungicides are used as prevention, not as cure.
So if the spots are on leaves already I have to spray a curative fungicides, is it?So for this year I'm going to spray penconazole.
Next year can I spray a better fungicide (one of the list), after the first leaves appear?

My goal is to graft these terebinths with pistacia vera, so I need healty plants!
So, according to you, how many years have I to treat them with fungicides to defeat pistoria?
Another question, I planted in field 10 of these plants, I treated them but is it possible that the fungus is in the ground plate?
If it is right, is it possible that the soil and plants near them will be infected?
How is it possible to defeat the fungus if it is in the soil?

[David Bracey]

The strobilurins are a "recent" discovery.  Gm for gm they are probably the most active of the fungicides. They have systemic, curative and protective properties with I think a fairly specific mode of action.  The dithiocarbamates on the other hand are protective fungicides but with a broad mode of action and were around in the 60s ...if I remember correctly. 

They are both good fungicides. It is a good idea to use them alternately to stop build up of resistance however I doubt if there is sufficient inncolum in your garden which might be selected for resistance!

I,m not sure how often you wil have to treat however in my experience with apple scab, mildew, vine diseases, coffee etc its non stop.  I have not check the life history of Septoria on pistachia...however it should be very easy to check on the web.  I do not think it comes " from the soil",  It probably carries over from season to season on old leaves nd stems.  Again you should be able to read about this.

[hereistay]

Sorry David, I modified my post adding other fungicides meanwhile you were writing your answer!!!
What can you tell me about the other fungicides I added?

[David Bracey]

The "conazoles" are triazole fungicides introduced in the 70s. They are all broad spectrum each having a slightly different spectrum of activity .  They are especially active on Rusts and Septoria of cereals. Since their mode of action is limited to a single site they are often used in progammes/mixtures with fungicides having a different mode of action. ( to delay the onset of resistance).

Strobilurins ....we, ve discussed.

Chlorothanil is in its own class.  Another broad spectrum fungicide  ?...

Start spraying early in the season,,,,before the spots appear....xheck on Wikepia the life -history...I think there may be other comments on the Forum.

[hereistay]

I found only this:

"EPIDEMIOLOGY AND DISEASE CYCLE

S. pistaciarum (and S. pistacina) overwinter in fallen leaves that were infected while on the tree in previous seasons. Pseudothecial primordia appear on fallen leaves early and young asci develop from then until February to early March. Most ascospores are mature
and ready for discharge from late April through May, and are released during or after rain. The optimum temperature for the development of pseudothecia and asci of S. pistaciarum is 10ºC (50ºF). Infections due to ascospores of S. pistaciarum have an
incubation period of about 10 days. Pycnidia with viable conidia of S. pistaciarum have been found on fallen leaves throughout winter and up to July, but their role in the disease is unknown. Secondary infections are caused by S. pistacina conidia, which spread by rain or
sprinkler water, and may continue until late fall. Spermogonia production begins on leaves on the tree in mid-September and continues on fallen leaves until December. Their role is unknown. Nothing is known about the epidemiology of S. pistaciae"

CONTROL
Septoria leaf spots are controlled with preventive fungicide sprays. Dithiocarbamates (zineb, mancozeb) are recommended. Also chlorothalonil and copper fungicides are also effective, but must be applied after fruit have reached 1 cm size to avoid phytotoxic damage to very young fruit. Benzimidazole fungicides are also effective. Applications should begin when the first leaves unfold and repeated if necessary monthly until early June. None of these fungicides are registered for California pistachios."

and...

"Septoria leaf spot
Septoria leaf spot is caused by the specie Septoria pistaciarum (Mycospharella pistaciarum). In years with high diseases incidence S. pistaciarum may also attack the fruits. This species primary infections are produced by ascospores released from pseudothecia in overwintering leaves on the263
ground. These diseases are common and especially in years with rainy springs, they may cause heavy defoliant in late summer. Leaf spot from natural infections are round to irregular, 1-2 mm diameter, with 1 to 20 flaslike fruiting structures of the fungus (pycnidia). Pycnidia measure 60-108
mm in diameter, pycnidiospore are colourness, curved to scale-shaped, and 44-85.5 x 3-3.9 mm, with 3 to 9 septa."

So...I don't know if it is septoria pistaciae or pistaciarum and wath the difference is!
If we wold listen to this article I would have to treat them montly from spring untill june, is it?
So the "best" way I have is to give, for example, trifloxystrobin and a dithiocarbamate alternately, from the first new growth untill June?
Another study about septoria on pistachios of Arizonsa USA, says that fungicides should be sprayed during high humidity months, in July-August, but I don't know if I can apply the same timing, but is it true that I bought them in october and the disease was just on them!
Anyway, 3 days ago I sprayed penconazole because I had only that fungicide and in two days I'm going to give a second treatment of attack.
After that second treatment have I to use another one of these fugicides (a curative one) or I have to continue to use penconazole for this year?
If I have to use again penconazole have I to use a lower dose how many times?

[David Bracey]

The answers are in the article....spores overwinter and are released in the spring , April..May after rain...When temperatures are above 10C.  To my mind that could be anytime around March.   new infections can occur monthly up to the end of July to mid September and maybe longer

Control should start when the first leaves unfold and continue every month until early June...that is if protective sprays such as the dithiocarbamates are used..  A thorough cover is essential!!!   

Lets assume the two Pistachias are the same...at least as far as control is concerned.

Keep the sprays going from first leaf, every month, until at least June.  You can use a dithiocarbamate on a routine every month basis, or dithio plus say a stribilurin at the same interval.  Keep all new grothnprtected with a covering of fungicide.

I found only this:

"EPIDEMIOLOGY AND DISEASE CYCLE

S. pistaciarum (and S. pistacina) overwinter in fallen leaves that were infected while on the tree in previous seasons. Pseudothecial primordia appear on fallen leaves early and young asci develop from then until February to early March. Most ascospores are mature
and ready for discharge from late April through May, and are released during or after rain. The optimum temperature for the development of pseudothecia and asci of S. pistaciarum is 10ºC (50ºF). Infections due to ascospores of S. pistaciarum have an
incubation period of about 10 days. Pycnidia with viable conidia of S. pistaciarum have been found on fallen leaves throughout winter and up to July, but their role in the disease is unknown. Secondary infections are caused by S. pistacina conidia, which spread by rain or
sprinkler water, and may continue until late fall. Spermogonia production begins on leaves on the tree in mid-September and continues on fallen leaves until December. Their role is unknown. Nothing is known about the epidemiology of S. pistaciae"

CONTROL
Septoria leaf spots are controlled with preventive fungicide sprays. Dithiocarbamates (zineb, mancozeb) are recommended. Also chlorothalonil and copper fungicides are also effective, but must be applied after fruit have reached 1 cm size to avoid phytotoxic damage to very young fruit. Benzimidazole fungicides are also effective. Applications should begin when the first leaves unfold and repeated if necessary monthly until early June. None of these fungicides are registered for California pistachios."

and...

"Septoria leaf spot
Septoria leaf spot is caused by the specie Septoria pistaciarum (Mycospharella pistaciarum). In years with high diseases incidence S. pistaciarum may also attack the fruits. This species primary infections are produced by ascospores released from pseudothecia in overwintering leaves on the263
ground. These diseases are common and especially in years with rainy springs, they may cause heavy defoliant in late summer. Leaf spot from natural infections are round to irregular, 1-2 mm diameter, with 1 to 20 flaslike fruiting structures of the fungus (pycnidia). Pycnidia measure 60-108
mm in diameter, pycnidiospore are colourness, curved to scale-shaped, and 44-85.5 x 3-3.9 mm, with 3 to 9 septa."

So...I don't know if it is septoria pistaciae or pistaciarum and wath the difference is!
If we wold listen to this article I would have to treat them montly from spring untill june, is it?
So the "best" way I have is to give, for example, trifloxystrobin and a dithiocarbamate alternately, from the first new growth untill June?
Another study about septoria on pistachios of Arizonsa USA, says that fungicides should be sprayed during high humidity months, in July-August, but I don't know if I can apply the same timing, but is it true that I bought them in october and the disease was just on them!
Anyway, 3 days ago I sprayed penconazole because I had only that fungicide and in two days I'm going to give a second treatment of attack.
After that second treatment have I to use another one of these fugicides (a curative one) or I have to continue to use penconazole for this year?
If I have to use again penconazole have I to use a lower dose how many times?

Suggest you talk to local growers, extension workers , your co -op for local details!