We live just south of Dallas and I’ve spent the last 6 years working on a 20 tree apple orchard in Blackland clay. I’ve plowed, made berms, added copious amounts of pine bark and sulfur in order to add drainage and acidify my 7.9 ph soil. I’m tired of seeing beautiful 3-5 year year trees die instantly in the heat of summer from cotton root rot. (I’ve worked in a plant lab and recognize the root fungi) I rip them up and replant, originally with m-111 and now with the newer rootstocks from Cornell. (I have yet to lose a Cornell rootstock but trying not to be too hopeful.) I am ready to start over with fruit that is more resistant to CRR. I’ve done a lot of research and it seems pecan and grape are about the best options? Any help is appreciated.
When conditions are right, cotton root rot can kill a wide range of dicot plants, including vineyards. Where the problem exists, growers need a rootstock for cotton root rot control. Champanel and Dog Ridge have been used with some success. The vigorous growth of wild mustang, Vitis mustangensis (Vitis candicans), appears to offer promise but unfortunately it is very difficult to propagate.
In 1931, a large A&M research vineyard was established at the Winter Garden Experiment Station at Winter Haven, Texas by Ernest Mortensen. More than a thousand grape and rootstock varieties were tested until 1952 when the project was closed. [. . .] Mortensen established Dog Ridge, Champanel and LaPryor as outstanding cotton root rot resistant rootstocks.
Cotton root rot problems can be reduced by using Dog Ridge. One rootstock, 110R can address more than one problem and is the leading choice for Texas today.
And the latter:
The vinifera varieties are all susceptible [to cotton root-rot] and many of the table varieties of the American grapes. This stimulated a study of root-stocks to overcome this. Collections of wild species were made and tested for root-rot resistance under field conditions at Winter Haven, Texas, by the Texas Agricultural Experiment Station. Munson had also made notes on this disease at Denison. Munson reported a high survival at Denison for bourquiniana, candicans, lincecumii and rotundifolia. He also reported high survival under severe root-rot conditions at Winter Haven for bourguiniana, candicans, champini, lincecumii, berlandieri, cinerea, monticola and rotundifolia.
To be successful as a grape root-stock, a variety must propagate readily by cuttings. This eliminates species that propagate poorly by cuttings such as candicans, berlandieri, monticola, and rotundifolia. The outstanding varieties of those which will root readily from cuttings are Dog Ridge and La Pryor. The latter is undoubtedly a natural hybrid of candicans and rupestris found on the Nueces river in Zavala County. It is very likely that Dog Ridge may also be a natural hybrid of candicans with another species.
A study of varieties for resistance to root rot and Pierces disease was also made at Winter Haven. A high survival was found for Black Spanish (Lenoir), Champanel, Delaware, Herbemont, Lomanto, Lukfata, Marguerite, Neva Munson, Nitodal, Salamander, Sunrise, Valhallah and Wine King.
Thanks much! This is very helpful. I’m thinking the champanel grape is usually the only one I can find. If I plant them and wait a year or two I can cut them off and splice another grape onto it right? Lomanto or Wine King grafted onto champanel should make a great team to combat both cotton root rot and Pierces disease while growing a high quality and much needed Texas wine grape? What’s the best graft for for grapes? And when is the best time to graft? Thanks again!
Pecan is heavily affected by cotton root rot. I am not aware of any tolerant rootstocks. Just hazarding a guess, you might look to see if any native hickories are growing in the area. If so, there is a good chance they are resistant. Find out what they are and see if pecan grafts can survive on them.
If you can come up with something for a rootstock, Monte Nesbitt has published recommendations for varieties.
No experience with grape grafting myself, but I understand it’s common to field graft them. Bench grafting might be easier in some ways, though, because grape grafts apparently need a number of days at around 80F to callus properly, and that would be easier to achieve under bench conditions (for instance, with a hot callus pipe) than in the field. A number of grafts are used. Perhaps someone with experience in these matters will chime in.
Anyway, that sounds like a solid plan. Good luck!