Topworked to Large Bearing Trees in 1960 and
Approximate Cost of Topworking
SINCE THE CHOCTAW AND SIOUX are relatively new pecan varieties, released in 1959 and 1962, respectively, little information has been reported concerning their bearing characteristics.
The purpose of this study is to present data pertaining to the yield of Choctaw and Sioux nuts from trees topworked in 1960 at the U. S. Pecan Field Station, Brownwood, Texas, and information concerning the costs incurred.
CHOTAW: This variety, tested under the number 46-15-276, originated from a controlled cross, Success X Mahan, in the USDA pecan breeding program.
The tree is vigorous in growth, of typical Eastern type, is less spreading in form than Success and branches freely. It begins to bud and leaf out relatively late in spring, or at about the same time as Success. The leaves are similar to those of the Success in size and appearance and are held late in autumn. The variety is photogynous; that is, the catkins mature and shed pollen after the pistillate flowers are receptive. The nuts mature at about the same time as those of Success. The variety is considered fairly precocious and bears heavy crops of nuts. Pecan scab has been noted on the variety in southern Louisiana.
The nuts are similar to those of the Success variety in size but the Choctaw is more symmetrical in shape. About 40 to 50 nuts are required to weigh a pound and it varies from 54 to 60 percent kernel, depending upon growing conditions. Shell thickness is comparable to that of the Schley variety. The nut kernels release well from the shell, and bright and uniform in color, smooth in form and are suited to shelling by machinery or hand. Inshell nuts require careful handling to prevent shell breakage because of their thin and brittle shells. Some cracking along the suture occurs when the nuts are exposed to the weather.
The Choctaw variety is under trial throughout the southern pecan growing areas.
SIOUX: This variety, tested under the number 43-4-6, originated from a controlled cross, Schley X Carmichael also made in the USDA pecan breeding program.
The tree is vigorous and has the form, foliage and chilling requirements of its parents. The tree exhibits excellent foliage. Strong growing shoots have a pronounced tendency to form lateral branches. This has been referred to as “fine" branching and is associated with very prolific bearing characteristics. Sioux is a protogynous blooming variety. Production is usually heavy and the nuts mature about mid-season or just prior to Western. The variety is precocious in bearing. Pecan scab has been reported on trees in Louisiana.
The nuts are about one-fifth smaller than those of Schley grown under comparable conditions. They have a somewhat flattened, pointed apex with a small projection from the basal end. About 60 to 70 nuts are required to weigh a pound, depending upon growing conditions. The shell is thin and well-developed nuts average 58 to 61 percent kernel. The kernel has excellent appearance and quality with a very smooth surface, bright color, high oil content, excellent pecan flavor and keeps well in storage. The parallel grooves of the kernel are small and the shell releases well. The septum side is smooth, with no projections of the septum into the kernel. It’s exceptionally high kernel quality and ease of cracking make the Sioux an excellent shelling variety.
*Research horticulturist, Crops, Research Division, Agricultural Research Service, U. S. Department of Agriculture, U. S. Pecan Field Station, Brownwood, Texas.
Fig. I. Representative growth of Choctaw and Sioux buds the seventh season following budding. Left, Choctaw tree budded onto Burkett stock; right, Sioux tree budded onto Jersey stock.
The Sioux is adopted to the Western pecan area and is under trial in the Southeast.
Topworking Burkett and Jersey Trees
A total of 325 trees --- 163 Burkett and 162 Jersey --- were cut back by removing all branches to a point where few were more than 3 to 4 inches in diameter in January 1960. AlI Burkett trees were topworked to the Choctaw variety and all Jersey trees topworked to the Sioux. Thirty-three Burkett trees were grafted to the Choctaw variety and an equal number of Jersey trees grafted to the Sioux variety in April 1960,by use of the inlay bark graft technique using precut scions. The remaining Burket and Jersey trees were topworked by patch budding into vigorous shoots developed near the end of the cut stubs in late Au- gust and early September of 1960.
The Burkett trees were chosen for topworking because of light production, poor nut filling, preharvest nut sprouting, poor foliage and susceptibility to pecan scab. The Jersey trees were topworked because of alternate-year bearing, susceptibility to phylloxera, poor nut filling and poor foliage.
At the time of dehorning in 1960, the Burkett and Jersey trees were 28 and 27 years of age, respectively. The Burkett trees were approximately 16.8 inches in diameter, and the Jersey, 15.6 inches. Table 1, which gives the number of cut stubs per tree at the time of dehorning, indicates the size of trees and number of grafts or buds required. The Burkett trees were the larger, and required more Choctaw buds and/or grafts than the Jersey trees topworked to Sioux.A shortage of Sioux budwood resulted in only one bud inserted per cut stub, as compared to three buds per stub in the case of the Choctaw.
The approximate cost incurred in topworking the 325 Burkett and Jersey trees to Choctaw and Sioux is noted in Table 2.The cost of aftercare and budding of the Burkett trees actually was greater than the average cost per tree, since these trees were cut back at a much greater height than the Jersey trees. The aftercare, or removal of the remaining Burkett and Jersey branches, should be completed by the end of the 1968 season.
Typical Choctaw and Sioux growth on the Burkett and Jersey stocks is shown in Figure 1.
TABLE 1. Number of Burkett and Jersey stubs budded or grafted to Choc-taw and Sioux, 1960.¹
No. Trees Av. No. Stubs
Variety Dehorned No.Stubs Per Tree
Burkett 163 2984 18.30
Jersey 162 2151 13.27
1Burkett trees were topworked to the Choctaw variety and the Jersey trees topworked to Sioux.
Yield of Choctaw and Sioux Nuts,1964-1966
A few nuts of the Choctaw and Sioux varieties were produced in 1963, or the third season after budding; however, yield records were not recorded until 1964. The mean yield of Choctaw and Sioux nuts per tree and per acre per year, 1964-1966, is given in Tables 3 and 4, respectively.
Yield records indicate that the Sioux variety is a somewhat more precocious bearer than the Choctaw, as indicated by the 1964 yield data for the mean yield per tree and mean yield per acre.
TABLE 2. Approximate cost of topworking 325 Burkett and Jersey trees to
Choctaw and Sioux varieties, 1960. ¹
Operation Total Cost Cost Per Tree
Dehorning and 758.93 2.34
removal of branches
Grafting and budding 1,134.00 3.50²
Aftercare (forcing 486.00 1.50
buds, removal of
cutting back grafts
and buds,1961 and 1962)
Aftercare, 1963226.80 .70
Aftercare, 1965 393.40 1.21³
Aftercare, 1967224.80 .69³
Total 3,223.93 9.29
¹These costs do not include the cost of budwood, tractor and equipment use, or costs of marking limbs for cutting back.
²The budding and grafting, operation was contracted by an experienced propagator and very little rebudding was necessary. Abud-take of 80 percent was specified in the contract and at least 80 percent bud-take was obtained on each tree.
TABLE 3. Mean yield of Choctaw and Sioux nuts in pounds per tree per year, 1964-1966.
Variety Yield Average
(Lbs. of nuts per tree)
1964 1965 1966
Choctaw 12.34 17.36 9.69 13.13
Sioux 20.76 14.40 33.70 22.95
PROCEEDINGS TEXAS PECAN GROWERS ASSOCIATION 45
TABLE 4. Mean yield of Choctaw and Sioux nuts in pounds per acre per year, 1964-1966.
Variety 50x 50 ft Spacing Average
(17 trees per acre)
Lb. of nuts per acre
1964 1965 1966
Choctaw 209.8 295.1 164.7 223.2
Sioux 352.9 244.8 572.9 390.2
Little difference in the yield of Choctaw and Sioux nuts occurred in 1965, but the Sioux trees produced more than three times that of the Choctaw trees in 1966.
Through the sixth season following topworking, the Sioux variety has been about twice as productive as the Choctaw, as indicated by the average production per tree and per acre for the 1964-1966 crops, Tables 3 and 4, respectively. This may be partly because of greater precocity in bearing associated with the Sioux variety.
The income received by the grower for Sioux and Choctaw nuts may depend largely upon whether they are sold in-the-shell, directly to a sheller or as shelled pecan halves. The Choctaw nuts would undoubtedly retail at a greater price than the Sioux on the in-shell market. If the pecan nuts were shelled, however, the Sioux kernels should bring a premium price as compared to the Choctaw because of the smooth, bright, uniform, high kernel quality associated with the Sioux variety.
Preliminary observations of the trees indicate that the 1967 crop of Choc- taw nuts will be somewhat greater than that of the Sioux. Periodic progress reports will be presented regarding the performance of these new varieties at the U. S. Pecan Field Station, Brownwood, Texas.
Mean yield records of 163 Choctaw and 162 Sioux trees, topworked onto large Burkett and Jersey trees, respectively, in 1960, are reported for the years 1964-1966.
Preliminary production records through the sixth year following topworking indicate that the Sioux variety is more precocious in bearing and has produced approximately twice as many nuts as the Choctaw variety in the early life of the trees. Present observations indicate that the Choctaw trees have set a somewhat heavier crop in 1967 as compared to the Sioux trees.
Progress reports will be presented concerning the performance of these varieties at the U. S. Pecan Field Station, Brownwood, Texas.
Since the Sioux exhibits excellent kernel qualities and is primarily a shelling pecan, and good quality Choctaw pecan nuts will bring a premium price in-the-shell, the return per acre for these varieties will depend largely on whether they are sold in-shell, directly to shellers or as shelled pecan halves.
The approximate cost of topworking the Burkett and Jersey trees to the
Choctaw and Sioux varieties, including aftercare through 1967, was approximately $10 per tree.