Patent Grant
PP29316
Latin name of the genus and species of the plant: Carya illinoinensis.
Variety denomination: ‘Whiddon’.
The present invention relates to a new and distinct variety of pecan tree named ‘Whiddon’. My new tree can be used in gardens or for commercial production of pecan nuts. This new tree was selected from seedlings grown from controlled pollination at the University of Georgia Horticulture Farm in Watkinsville, Ga., in 1990. The ‘Whiddon’ selection resulted from crossing ‘Desirable’ (unpatented) as the seed parent with ‘Pawnee’ (unpatented) as the pollen parent (
‘Whiddon’ is distinguished from other pecan varieties known to the inventor due to the following unique combination of characteristics: consistent and acceptable fruit production, small fruit cluster, moderately early nut maturity, large nut producing mammoth kernels with excellent color and no speckling, high resistance to scab fungus (Fusicladosporium effusum), moderate resistance to black aphid (Melanocallis caryaefoliae), and moderate resistance to pecan leaf scorch mite (Eotetranychus hicoriae).
Asexual reproduction of ‘Whiddon’ by grafting, (top working) onto ‘Desirable’ pecan trees in 2004 and 2006 at a location in Albany, Ga. and onto ‘Cape Fear’ (unpatented) trees in 2006 at a location in Leary, Ga. was performed in order to evaluate these trees. Asexual reproduction of ‘Whiddon’ has shown that the forgoing characteristics come true to form, are firmly fixed, and are established and transmitted through succeeding propagations.
Certain characteristics of this variety, such as growth and color, may change with changing environmental conditions (e.g., light, temperature, moisture, nutrient availability, or other factors). Color descriptions and other terminology are used in accordance with their ordinary dictionary descriptions, unless the context clearly indicates otherwise. Color designations are made with reference to The 2001 Royal Horticultural Society (R.H.S.) Colour Chart.
The colors of an illustration of this type may vary with lighting and other conditions. Therefore, color characteristics of this new variety should be determined with reference to the observations described herein, rather than from these illustrations alone.
Tree form of ‘Whiddon’ is unusually upright in contrast to both parents and almost all other pecan cultivars. Thus, ‘Whiddon’ trees can be planted in higher tree density than most cultivars. The timing of bud break of ‘Whiddon’ is similar to ‘Huffman’ (U.S. Plant Pat. No. 25,465), ‘Morrill’ (U.S. Plant Pat. No. 23,335), and ‘Stuart’ (unpatented) pecan trees (Table 2). Thus, ‘Whiddon’ is less susceptible to late-spring freezes than ‘Byrd’ (U.S. Plant Pat. No. 20,867), ‘Cunard’ (U.S. Plant Pat. No. 24,373), ‘Desirable’, and ‘Treadwell’ (U.S. Plant Pat. No. 25,740). The leaves of ‘Whiddon’ are forest green as in ‘Pawnee’, but are unlike the pale green of ‘Desirable’. Leaflet orientation is similar to seed parent ‘Desirable’ and most pecan genotypes; that is leaflets droop from the rachis and is unlike pollen parent ‘Pawnee’ where the opposite leaflets are oriented at 180 degrees relative to each other. Leaflet margins on vigorous shoots are convoluted. The stigmatic surface of ‘Whiddon’ is oxblood, similar to the oxblood color of both parents and in contrast to the green stigma of ‘Wichita’ (unpatented) and some other cultivars. ‘Whiddon’ like ‘Tom’ (U.S. Plant Pat. No. 26,705) is highly resistant to the scab fungus (Table 3) and contrasts with the high susceptibility of both parents and to almost all other pecan cultivars. In the humid southeastern United States, resistance is a major attribute of ‘Whiddon’. Mature bark is pecked by yellow bellied sapsucker as in ‘Stuart’ and ‘Wichita’.
Table 1 below compares periods of pollen shedding and stigma receptively for ‘Whiddon’ and selected other pecan cultivars (all unpatented) in April 2012, Watkinsville, Ga.
Table 2 below compares bud break date for ‘Byrd’, ‘Tom’, ‘Huffman’, ‘Morrill’, ‘Cunard’, ‘Treadwell’, ‘Stuart’, ‘Whiddon’, and ‘Desirable’ pecans. Observations were of trees growing in Watkinsville, Ga.
zAverage of years 2005, 08, 09, 10, 11, 12. Replication over years.
Table 3 below compares fruit scab susceptibility of ‘Whiddon’ with ‘Byrd,’ ‘Morrill,’ ‘Cunard’, ‘Treadwell’, ‘Tom’, ‘Huffman’ and ‘Desirable’. In addition, ‘Pawnee’ has been observed to be more susceptible to scab disease than ‘Whiddon’ when observed at two Georgia growing locations.
x1 = no lesions, 2 = occasional lesions, <10% of fruit with scab, 3 = lesions common on fruit but not damaging, 1-50% of fruit with scab, 4 = wide spread lesions on fruit but not damaging, 51-75% of fruit with scab, 5 = widespread lesions on fruit, fruit size suppressed. Fungicides applied at both locations.
yn = 19, sprayed with fungicide.
zn = 5, sprayed with fungicide.
Table 4 below compares nut characteristics of ‘Treadwell’, ‘Byrd’, ‘Tom’, ‘Cunard’, ‘Morrill’, ‘Elliott’, ‘Huffman’, ‘Whiddon’, and ‘Desirable’ pecans. Observations were of trees growing in Albany, Ga., from 2009-2012.
z Length to width ratio = nut length divided by width. Width was measured midway the length of the nut and across the suture.
y Nut flatness = ratio of nut width across suture to width between suture. Measurement was made midway the length of the nut.
x Date when shuck dehiscence had occurred on 50% of the fruit, from September 1.
Pecan nuts of large size that mature relatively early command a premium price. The price per pound normally declines as the harvest becomes later. Consequently, cultivars that exhibit early maturity at harvest are commercially important. The color of a kernel's seed coat (lighter is preferred), and the percentage kernel of the nut also affects the selling price of pecans. Although the nut maturity of ‘Whiddon’ is about 15 days later than nut maturity of ‘Byrd’, it is about 11 days earlier than ‘Desirable’ (Table 4). ‘Desirable’ is believed to be the leading cultivar now being planted in new orchards in Georgia. Even though the nut maturity of ‘Whiddon’ is later than ‘Byrd’, the maturity date is still early enough to be considered an early market cultivar. The later harvest date of ‘Whiddon’ is advantageous in one respect because a number of growers of pecans in southwest Georgia also grow peanuts. The harvest date of ‘Byrd’ ‘Cunard’, ‘Pawnee’, ‘Tom’, and ‘Treadwell’ pecans conflicts with the peanut harvest date. ‘Whiddon’ matures at the end of the peanut harvesting season, making it a more suitable early cultivar for peanut growers that can harvest ‘Whiddon’ pecans following the peanut harvest. In addition to use in a new planting, ‘Whiddon’ is well suited as a replacement tree or as an inter plant in a ‘Stuart’-‘Schley’ (unpatented), ‘Desirable’ orchard, a common combination in the southeastern United States. The nut maturity date of ‘Whiddon’ is similar to ‘Stuart’ and ‘Schley’; allowing a once over harvest of the blended nuts. In contrast to ‘Treadwell’, and similar to ‘Tom’, the shuck opens widely which minimizes premature germination and promotes rapid pre harvest drying of the nut. Unlike ‘Huffman’ and ‘Treadwell’, shuck surface is not russet. Also unlike ‘Huffman’, shuck sutures of ‘Whiddon’ are not serrated.
From Table 4, ‘Whiddon’ nuts are large (wt./nut), equal in size to ‘Cunard’ and larger than ‘Morrill’ and ‘Desirable’ and less than ‘Huffman’. Consequently, the large kernels of ‘Whiddon’ are well suited to the “mammoth half” market. Nut length is less than ‘Cunard’ and ‘Morrill’ and similar to ‘Desirable’ and ‘Huffman’. General nut shape (length/width) is similar to ‘Desirable’, ‘Treadwell’, and ‘Byrd’, but is less oblong than ‘Cunard’ and ‘Morrill’. Cross-section (nut flatness) of ‘Whiddon’ nuts are near round (flatness ratio 1.01) and intermediate to ‘Huffman’ and ‘Desirable’ and more symmetrical than ‘Treadwell’, ‘Byrd’, ‘Tom’, ‘Cunard’, ‘Morrill’, ‘Elliott’, ‘Huffman’, and ‘Desirable’. The shell is thicker in ‘Whiddon’ than ‘Huffman’ and ‘Desirable’. The percentage kernel of ‘Whiddon’ is higher than ‘Desirable’ and similar to ‘Huffman’. In pecans, the percentage kernel is a direct function of shell thickness and the percentage of the shell cavity filled with kernel. The percentage kernel of ‘Huffman’ and ‘Desirable’, in spite of a thinner shell, is not greater than ‘Whiddon’; because of a concave kernel, dorsal grooves that are wide, and a central partition that is thick, which reduces the percentage of shell cavity filled with kernel. The percentage kernel of ‘Whiddon’ nuts is higher than the industry standard ‘Desirable’.
Under stress, primarily fruiting stress, and when ‘Pawnee’ pecan trees are grown in humid southeastern United States, the kernel's seed coat of ‘Pawnee’ pecans can develop conspicuous and unattractive dark spots. This speckling reduces the marketability of these nuts. Speckling has not been observed to be a problem of ‘Whiddon’ nuts grown in Georgia. Kernel color of ‘Whiddon’ fruit is good (
Table 5 below compares precocity of ‘Cunard’, ‘Byrd’, ‘Treadwell’, ‘Tom’, ‘Desirable’, ‘Morrill’, ‘Whiddon’, ‘Elliott’, ‘Huffman’, and ‘Stuart’ pecans.
zYears from transplanting from the nursery.
Table 6 below compares alternate bearing tendency of ‘Byrd’, ‘Treadwell’, ‘Huffman’, ‘Tom’, ‘Cunard’, ‘Morrill’, and ‘Whiddon’ pecans. Observations were of trees growing in Albany, Ga.
yYears after top working mature trees to the respective cultivar.
zAnnual production maintained by fruit thinning.
Table 7 below compares pounds/tree, weight per nut, nuts per pound, percentage kernel of trees top workedz, namely the comparison is of ‘Morrill’, ‘Cunard’, ‘Treadwell’, ‘Huffman’, ‘Tom’, and ‘Whiddon’ pecans, observed in Albany, Ga., from 2009-2012.
zTop working simulates a mature tree and allows for earlier evaluation of alternate bearing, kernel development under heavy fruit load, and suitability for mechanical harvest and ease of fruit thinning
yCunard and Treadwell were fruit thinned as needed. About 50% of the fruit was removed. Other cultivars were not fruit thinned.
‘Whiddon’ is not precocious relative to ‘Byrd’ (Table 5). Also, the original ‘Whiddon’ tree bore its first fruit the 13th year from planting as seed. In comparison, the original tree of ‘Byrd’ first fruited the 7th year from planting as seed. ‘Whiddon’ is not as precocious as ‘Byrd’ as is also indicated by the onset of alternate fruit-bearing in ‘Byrd’ trees the third year from top working in contrast to alternate fruit bearing in ‘Whiddon’ trees in the 8th year (Table 6). Precocity of ‘Whiddon’ is similar to ‘Desirable’ and ‘Morrill’ (Table 5). Although not precocious, prolificacy as mature top worked trees is good and similar to ‘Morrill’, ‘Cunard’, ‘Treadwell’, ‘Huffman’, and ‘Tom’ (Table 7). Thus far, alternate bearing of ‘Whiddon’ has been relatively minor or about 50% during the “off” year relative to the “on” year. Thus, the mainly annual production of ‘Whiddon’ is as in ‘Desirable’ and both ‘Whiddon’ and ‘Desirable’ have a small fruit cluster size (Table 8).
As indicated in (Table 8), the cluster size of ‘Whiddon’ and ‘Desirable’ is similar. It does appear that ‘Whiddon’ has lower density of fruiting shoots than ‘Byrd’ and is similar to ‘Desirable’. Because of the small cluster size and consistent production exhibited by ‘Whiddon’ following top working to mature pecan trees, ‘Whiddon’ is expected to bear quite consistently with increasing tree maturity as occurs with its seed parent ‘Desirable’. ‘Whiddon’ is superior to ‘Desirable’ in having a larger nut, higher percentage kernel, and high resistance to scab disease.
Table 8 below compares fruit cluster size of ‘Byrd’, ‘Desirable’, ‘Huffman’, ‘Tom’, ‘Morrill’, ‘Pawnee’, Cunard’, and ‘Treadwell’, ‘Elliott’, and ‘Whiddon’ pecans. Observations were of trees growing in Watkinsville, Ga. Data are averages of three years, 2005, 2006, and 2008.
zCluster counts made after the second drop was completed.
Tables 9-11 below compares N scorch, black pecan aphids, and pecan leaf scorch mite resistance of ‘Whiddon’ to other pecan varieties.
Table 9 below compares leaf susceptibility of ‘Byrd’, ‘Morrill’, ‘Cunard’, ‘Treadwell’, ‘Whiddon’, ‘Huffman’, and ‘Desirable’ pecans to N scorchy. Observations were of trees growing in Leary, Ga. in 2009.
yN scorch can cause severe premature defoliation in May and July and is induced by an imbalance of N and K in the leaf.
z1 = no scorch
Table 10 below compares leaf susceptibility of ‘Byrd’, ‘Huffman’, ‘Morrill’, ‘Cunard’, ‘Tom’, ‘Treadwell’, ‘Sumner’, ‘Whiddon’, and ‘Desirable’ to black pecan aphid. Observations were of trees growing in Leary, Ga.
z1 = no injury, 2 = <1% of leaves with injury, 3 = 1-10% of leaves with injury, 4 = 11-50% of leaves with injury, 5 = >50% of leaves with injury and partial defoliation.
Table 11 below compares leaf susceptibility of ‘Byrd’, ‘Tom’, ‘Morrill’, ‘Huffman’, ‘Cunard’, ‘Treadwell’, ‘Whiddon’, ‘Sumner’, and ‘Desirable’ to pecan leaf scorch mite. Observations were of trees growing in Leary, Ga.
1 = no damage, 2 = trace, 3 = multiple lesions, 4 = minor defoliation, 5 = severe defoliation.
‘Whiddon’ has excellent resistance to N scorch, in contrast to ‘Huffman’ and especially to its seed parent ‘Desirable’ (Table 9). Resistance to black pecan aphid by ‘Whiddon’ is similar to ‘Desirable’ (Table 10) and resistance to pecan leaf scorch mite of ‘Whiddon’ is similar to ‘Huffman’ (Table 11).
Under the humid growing conditions in southeastern United States, the pecan fruit is highly susceptible to splitting during the “water stage” (liquid endosperm stage) of fruit development. Fruit split can occur following rain and accompanying prolonged high humidity in early August in Georgia. Water split has not been observed in ‘Whiddon’. The lack of split may be due to the timing of fruit development. Water split is most likely to occur on cultivars when the maximum liquid endosperm stage occurs during the first two weeks in August; which often coincides with the rainy period in Georgia. Typically, rainfall in Georgia sharply decreases after August 15th. The maximum liquid endosperm stage in ‘Whiddon’ fruit grown in Georgia usually occurs after August 15th.
The ‘Whiddon’ pecan tree is therefore an improved new and distinct pecan.
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| 2014 Fort Valley State University retrieved on Aug. 1, 2017, retrieved from the Internet at <https://portal.nifa.usda.gov/web/areera/Reports/2014/2014-Fort-Valley-State-University-and-University-of-Georgia-Combined-Research-and-Extension-Annual-Report-of-Accomplishments-and-Results.pdf> pp. 1-3. |
