hereistay
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Joined: Mon May 08, 2017 12:57 pm

Black spots on young pecan nuts seedlings: what can it be?

Hi there!
I'm from Central Italy and I sowed some pecan nuts in February.
A week ago they started to germinate.
Today I notice some black spots on leaves and on little trunks.
Can it be scab?
What can I do now?
Wait and see what happens or should I treat them with anti-scab fungicide?
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Last edited by hereistay on Wed May 17, 2017 6:33 pm, edited 1 time in total.

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Lindsaylew82
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Location: Upstate, SC

Re: Black spots on young pecan nuts seedlings: what can it b

Hi!

It does look like scab to me. With those seedlings as small as they are, and the scab as bad as it already looks, I doubt that these will do well regardless of what you do.... I hate that!

Best thing that you can do about scan is begin with types pecans that are known to be scab free (resistant) in your area.

I'm not sure of Italy, but here in the southern states, Dooley, Hirschi, and Maramec are so prone to scab, that they are just avoided here.
Jenkins and Syrup Mill (maybe Syrup Hill?) are good all around cultivars because they have excellent scab resistance (for now...fungal disease is ever evolving) and they also have excellent self pollination rates. (Pecan trees usually produce pollen and buds at different times to increase genetic diversity but these 2 cultivars have pollen and bud times that overlap, very nicely, per individual tree. This means you can plant just one of this type and still get excellent production! )
Lindsay
Upstate, SC
USDA Zone 7b/ Sunset Zone 31

hereistay
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Posts: 14
Joined: Mon May 08, 2017 12:57 pm

Re: Black spots on young pecan nuts seedlings: what can it b

Thank you for your reply Lindsey.
In Italy there are some pecan orchards but this nut is relatively new.
The first orchard was established about 40 years ago but I know that there are secular plants in Sicily...maybe Italian migrants brought back some nuts during '800.
Anyway it's simple to find pecans from seeds in Sicily.
About grafted plants there is not a wide choice : Cape Fear, Cheyenne, Shoshoni, Kiowa, Pawnee and maybe another 2 or 3 cultivars.
I have two grafted plants planted in March 2016, a Cape Fear and a Kiowa.
They seem to suffer of scab maybe because I have big walnuts nearby and they are probably affected by scab.
I used to spray systemic fungicide and I was able to control it during these 2 years.
I hope you are wrong, but little plants with scab after a week is a mess and I think too I'll never see them grow.
I'm trying to have some plants to graft (with scions from my two plants).
Last year I tried to have some plants.
They looked good but after a month started to develop black veins or something similar and all died one by one.
You can see pics of them below
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Lindsaylew82
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Location: Upstate, SC

Re: Black spots on young pecan nuts seedlings: what can it b

Yep also scab.

Let me see if I can find a link somewhere with good cultivars.

Pawnee for some reason is sounding alarms, like it's bad with scab as well.

I will post back!
Lindsay
Upstate, SC
USDA Zone 7b/ Sunset Zone 31

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Lindsaylew82
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Joined: Thu May 22, 2014 1:26 am
Location: Upstate, SC

Re: Black spots on young pecan nuts seedlings: what can it b

If you see scab near the base of those stems, most of the above will shrivel and die. Once it affects the vasculature, it cuts off flow to the farther plant. That's why you see the entire portion of the limb tips die off. It's really a nasty fungus. Fungicides can control it, but unless you are very persistent in controlling it, you likely just increase resistance of the scab to the fungicides you use. The fungi that aren't killed, reproduce and pass on that resistance to future generations. Resistant cultivars are the best resource here... save you lots of time, money, and man power.

Here is a cultivar link that is very similar to my SC book:
https://www.aces.edu/pubs/docs/A/ANR-0674/ANR-0674.pdf
Lindsay
Upstate, SC
USDA Zone 7b/ Sunset Zone 31

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