Pecan scab ratings

I’m working on an update to the pecan spreadsheet to show average scab susceptibility for most of the important cultivars. There are several factors in evaluating scab such as where the tree was grown, how it was managed, local climate, scab variants present in the environment, etc. I’d be interested in feedback from pecan growers over the summer as they see scab develop on their trees.

I’d like this to be a bit more nuanced than most current pecan literature. Typical ratings are on a scale from 1 to 5 where 1 is little or no scab and 5 is eaten alive with it. As examples, I would rate Pawnee as 5 meaning it is so covered in scab as to never produce a viable crop. I would rate Stuart 2 because in dry years it is tolerant enough to make a crop. I rate Amling as 1 because it is never affected to any significant degree by scab. Adams #5 also is almost totally clean of scab.

Please consider contributing to this thread to provide data that helps other growers choose varieties!

Here are the varieties I have listed with 1.0 rating for scab:

Adams #5

Note: Elliott scab resistance has been compromised enough that it is no longer rated 1.


I know for a type 1 pecan tree major was suggested to me. The other pecan I have is one of those self fertile pecan specific to starkbros. I think some say it is silverback but Stark Bros calls it Surecrop I believe. We had a -15 degree day this winter so we will see if it survived. Edit maybe my type to is southern giant.

All pecans are dichogamous but some of them overlap pistillate flowers with pollen shed. Even if they can self-pollinate, they produce larger and healthier crops when cross-pollinated. Major is unique in the pecan world as a pecan with significant introgression of bitternut genetics. It appears to be associated with scab tolerance and wood strength. Major is one of the best cultivars for areas with frequent ice storms.

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My Sumner pecan tree does not seem to be susceptible to scab.

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Sumner has very good resistance but it has been partially compromised such that spraying is necessary when grown commercially. I have it rated as 1.3 which is a very good level of tolerance. I’m at the point of wondering what would happen if Sumner was crossed with Major. There is potential for a very good pecan tree adapted further north than Sumner. Thanks for the info!


Does anyone here have a Choctaw pecan tree or know anything about this cultivar? Years ago, I was tempted to purchase one in a local nursery. Because it was pricey, and I was not sure about it I declined. I think from what I have read that does not have good scab resistance.

You are fortunate to have declined. Choctaw is an extreme alternate bearer with a heavy crop of low quality nuts one year and no nuts the next. If you are looking for a couple of varieties to complement Sumner, consider these as possibilities. Avalon type 2, Gafford type 1, or Amling type 1. Amling is exceptionally disease and pest tolerant with little or no scab and very few insect pests bother it. It is a superb yard tree but not productive enough for commercial use. Gafford is very resistant to scab but tends to overbear some years. Avalon is a good possibility though somewhat susceptible to black aphids. Avalon is type 2 the same as Sumner so would not be a good pollination partner. You might consider putting in Avalon and Amling to have pollination partners. Amling would pollinate both Sumner and Avalon. Alphabetical Cultivar List - Cultivars | Pecan Breeding


Thanks for the link.

It’s doubtful to me that I have pollination problems with my Sumner tree. I have what’s supposed to be a Cape Fear tree (type 1) nearby. There is a couple of wild pecan trees about 100 yards away. In addition, I have a neighbor with plenty of pecan trees about a quarter of a mile away. My problems last year were stinkbugs, squirrels, and drought.

Hopefully, a Stuart pecan tree that I planted 10 years ago will have pecans this year. Scab aside, is there really a higher quality pecan than Stuart?

Several years ago, a friend gifted me a 3-pound bag of Stuarts from a tree in Memphis. Large blocky pecans. Best pecans I have ever ate. He related to me how that decades ago that there was a large pecan plantation in what is now east Memphis. Furthermore, I remember how he lamented that someone nowadays would purchase a house with huge pecan trees on the lot and then have the trees cut down because they do not want nuts in their yard. He could not understand such people. I can’t either.

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Yep. There was a home just a mile or two from me that had a huge old pecan that bore massive crops of nuts… I’m presuming it was just a random seedling, but they were pretty decent nuts. The family that had bought the property and moved in had it removed just because they didn’t want to have to deal with the nuts. That’s not a ‘problem’ that many people in KY have to ‘deal with’… but I cannot even fathom the thought process behind that…


Yes, there are several pecans that are higher quality than Stuart. Stuart is known for producing fuzz on the kernels, especially in dry years. It won’t fully fill the kernels unless well fertilized and watered. That said, every single variety of pecan has some failing. The standard for highest quality pecans is Schley. However, Schley is totally susceptible to scab, so much that it can’t be grown economically without extensive fungicide sprays. Schley is an ancestor to about 1/2 the varieties of pecans grown commercially today.

|Cape Fear|schley seedling NC|
|Cherokee|schley X Evers|
|Forkert|Success X schley|
|Giftpack|schley seedling|
|Halsly|schley X Halbert|
|Hopi|schley X McCulley|
|Jackson|Success X schley|
|Linberger|schley seedling?|
|Moreland|schley Seedling|
|Navaho|Apalachee X Wichita|
|Oconee|schley X Barton|
|Royal|schley seedling CA|
|Shawnee|schley X Barton|
|Sioux|schley X Carmichael|
|Slybert|schley X Halbert|
|Sumner|schley seedling|
|Tucker’s Favorite|Stuart X schley|
|Willmann|Commonwealth X schley|
|Zinner|Stuart/schley seedling?|

In addition, Mahan is thought to be a seedling of Schley (unproven at this time). If it is, the number of offspring from Mahan would nearly double Schley’s count.

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From your link-

Stuart: 47 #Nuts/lb 45% Kernal
Mahan: 50 #Nuts/lb 56% Kernal
Schley: 71 #Nuts/lb 53% Kernal

‘Mahan’ is still sold by nurseries primarily because people request it for its large size. You might get a few good years from a young tree, but soon the nuts will no longer fill and quality will often be inedible. Homeowners should opt instead for a medium to small sized nut which has a much better chance of producing a nice kernel.

I guess I am too hard-headed and old-fashioned, but I’m still betting on my Stuart and Mahan pecans. I am not big on little pecans. :t_rex: :sauropod: :bomb:

You would be better served to graft the Mahan over to Lakota. It overbears, but still manages a good crop most years. Stuart will work if you don’t get scab too bad. What varieties do you have other than Stuart, Mahan, and Sumner?

Here are all the pecans that are over 10 grams per nut.

Variety Origin Adapt Type Grams
Podsednik Seedling TX II 20.62
Mahan-Stuart Mahan X Stuart II 15.12
Rome Seedling LA 15.12
Silverback Seedling OK II 14.63
Mahan Seedling FL II 14.1747625
Pensacola Cluster Seedling FL II 14.1747625
Imperial Seedling TX 14.17
GraKing Seedling OK I 12.95978286
Jackson Success X Schley O 12.95978286
Choctaw Success X Mahan USDA II 12.25925405
Comanche Burkett X Success USDA II 12.25925405
GraPark Giant Seedling TX 11.94
GraZona Seedling AZ II 11.34
Cherryle Seedling AL II 11.33981
Shoshoni Odom X Evers USDA II 11.06322927
El Mart Mahan seedling II 11.06
Iago Seedling TX II 11.06
Waco Wonder Seedling TX 10.8
Grabohls Mahan X Texas Prolific II 10.8
GraCross Seedling TX II 10.8
Ivey Frotscher seedling GA II 10.8
Keilers Seedling TX II 10.8
Cunard Wichita X Pawnee GA II 10.79981905
Whiddon Desirable X Pawnee USDA II 10.55
Wichita Halbert X Mahan USDA II 10.55
Odom Russell X Success II 10.55
Burkett Native seedling TX SW II 10.54866047
Price-Fleming Seedling NC 10.31
Tucker’s Favorite Stuart X Schley 10.31
Ellis Seedling GA II 10.30891818
Gloria Grande Stuart seedling SC II 10.30891818
Kernodle Seedling AL II 10.30891818
Lipan Cheyenne X Pawnee USDA I 10.30891818
Maramec Mahan seedling II 10.30891818
Nacono Cheyenne X Sioux USDA II 10.30891818
Pawnee Mohawk X Strkng Hrdy Giant USDA I 10.30891818
Tanner Wichita X Pawnee GA I 10.08
Carter Seedling AL II 10.08
Halsly Schley X Halbert 10.08
Nelson Seedling MS 10.08
Apache Burkett X Schley USDA II 10.07983111
Cape Fear Schley seedling NC O 10.07983111
Excel Success X Pierce? II 10.07983111
Jubilee Seedling AL O 10.07983111
Kiowa Mahan X Desirable USDA II 10.07983111
Mohawk Success X Mahan USDA II 10.07983111
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In addition to Stuart, Mahan and Sumner I have a Cape Fear (type 1). I suspect that the Cape Fear is mislabeled because it has produced really small nuts and is listed as having 55 nuts/lb. The Cape Fear and Sumner have been in the ground 12/13 years. They came from Willis so they could be anything although the Sumner seems true to its label. I have considered grafting to the Cape Fear. Would it be worthwhile to graft a 12-year-old to something else that is also type 1? I know that pecan does not graft easily.

The Mahan and Stuart trees have been in the ground 10 years and came from 1st Monday flea market (great deals!). The Mahan had a handful of perfect pecans last year. I gauge the quality of a pecan tree as to what the pecans look like after they produce rather than anything that I read about the variety. Of course, it’s okay to read about pecans before selection though.

Really, I just consider these pecans to be yard trees. I won’t forget to run the water hose to them in case of drought this summer though.

I understand the concern for scab. I’ve seen old pecan trees that were completely ate up with it. Worthless pecans. :disappointed:

If it produces small pecans now, it will always produce small pecans. Amling and Gafford are two very good options for topworking. Both are type 1 and would pollinate the others. Both produce reasonably good size pecans. Amling’s weakness is that it is a light cropper though that also means it makes a decent amount of pecans every year. Amling is also highly resistant to scab and is rarely bothered by pecan pests. Gafford is an overbearer and can have dark kernels in some conditions. Gafford also is highly resistant to scab. Both are acceptably good pecans. If I had the same trees, I would topwork the faux Cape Fear.

To continue descriptions, Stuart is the old standard pecan in the Southeast. It is only moderate in kernel quality and can have fuzz on the kernels when stressed. It was once highly resistant to scab, but it no longer has that status. Stuart as an older tree might make a crop one year in ten. Mahan is a severe alternate bearer that makes huge pecans but can’t fill them. It produces large pecan clusters with 5 to 6 pecans each. This is a recipe for problems as a mature tree. It may produce good pecans as a young rapidly growing tree, but as it matures, that will turn into unfilled or partially filled pecans that even squirrels reject. Cape fear (the real one) is scab tolerant but very susceptible to bacterial leaf scorch. It is generally a good yard tree but not acceptable for commercial production due to scorch issues. You already know a good bit about Sumner. It used to be highly resistant to scab but that resistance has faded in the last 10 years. As a yard tree, it will be hard to beat. It’s only significant flaw is very late maturity of the nuts. You will rarely harvest them before November. Cape Fear, Sumner, and Mahan are all seedlings from Schley!

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I can attest to that for the Sumner! Is that the reason that its not recommended to northern latitudes?

Yes, late maturity and a tendency to leaf out just a bit too early. As noted earlier, I’d love to see Major crossed with Sumner. The potential for a highly scab resistant large earlier maturing pecan is very high.

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If I were to look for a cold tolerant and scab resistant pecan like major that will pollinate major what should I choose? I already have the southern giant from Stark bros but I question it’s cold hardiness as places list it as zone 6b.

Kanza, which is Major x Shoshoni is a late pollen Type II with excellent scab resistance and good kernel quality. Oswego & Posey fit, but don’t shed pollen as late as Kanza, IIRC
Chetopa is a good pollenizer for Major, as well, but scabs badly here.

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Which ones deal with the cold the best that will pollinate major?

cold: that is where the ouch comes in with pecans. You are not just dealing with cold, but also with a short growing season. The varieties I have linked for your location are Kanza, Lucas, Warren 346, and Yates 152. Warren 346 is a very small but very early maturing pecan. I don’t have heterodichogamy data for it - don’t know if it is type 1 or 2 - but the extremely early maturing may be a compelling reason to grow in your climate. Lucas also is a small and otherwise unremarkable pecan but it is a type 2 and I show it as a decent pollination partner for Major. Kanza may be a stretch for your climate. It is type 2 and works as a pollinator for Major. The only question about Kanza is whether or not it can mature nuts for you. I would need to find out a lot more about your climate to make a good guess. Yates 152 has some potential. I don’t know enough about it to give much more than decent size and reasonably early maturity. Oswego is a bit long season for your climate so avoid it.

I would also put a huge exclamation point about the rootstock used. For your climate, a well adapted northern rootstock is required. Major makes a decent rootstock.

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