Performance of 15 Pecan Cultivars and Selections over 20 Years in Southern Georgia

Fifteen pecan (Carya illinoinensis) genotypes were evaluated over a period of 20 years in a test orchard located near Tifton, Ga. Genotypes tested included seedling selections (`Candy', `Maramec', `Melrose', `Moreland', `Sumner', and `Western Schley'), USDA releases (`Creek', `Kanza', `Kiowa', and `Pawnee'), and USDA selections (USDA 41-19-20, USDA 53-11-139, USDA 53-9-1, USDA 57-7-22, and USDA 64-11-17). Actual yields were measured for each tree in the test throughout the test period and the alternate bearing intensity (I) of each cultivar was calculated. Average annual nut production in years 1 to 10 ranged from 19 lb (8.6 kg) in the precocious cultivar `Candy' to 6 lb (2.7 kg) in the nonprecocious cultivar `Melrose'. Although a wide variation was seen in the average yield of clones in years 11 to 20, differences were not significant. A subsample of nuts was taken for each tree annually and percent kernel, nuts/lb, specific gravity, and nut volume were determined. Significant differences were found between clones for each of these traits. Most clones were not acceptable for commercial use in Georgia due to small nut size, poor kernel quality, or excessive alternate bearing. Recommended clones include: `Pawnee', which produced large nuts of excellent quality with an early harvest date, `Sumner', which produced large nuts of moderate quality with a late harvest date, and `Kiowa', a precocious bearer of large, good-quality nuts.

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Performance of 19 Pecan Cultivars and Selections in Southern Georgia

HortTechnology ◽

10.21273/horttech.24.3.407 ◽

2014 ◽

Vol 24 (3) ◽

pp. 407-412

Author(s):

Patrick J. Conner

Keyword(s):

Scab Resistance ◽

Development Programs ◽

Alternate Bearing ◽

Department Of Agriculture ◽

Breeding Programs ◽

Cultivar Development ◽

Kernel Quality ◽

Pecan Scab ◽

Nut Production ◽

Southern Georgia

Nineteen pecan (Carya illinoinensis) clones were evaluated over a period of 18 years in a test orchard located in southern Georgia. Clones tested were primarily U.S. Department of Agriculture selections, but two grower-discovered cultivars, Jubilee and Surprize, were also trialed. Annual yields were measured for each tree in the test throughout the test period and the alternate bearing intensity of each cultivar was calculated. Average annual in-shell nut production in years 1–10 ranged from 12 lb in the precocious USDA 76-4-41 to 0 lb in the non-precocious USDA 72-8-4. Wide variation was seen in nut production of trees in years 11–18, averaging from 10 to 60 lb nut yield per year. A subsample of nuts was taken from each tree annually and percent kernel, nuts per pound, specific gravity, and nut volume were determined. Significant differences were found between clones for each of these traits. Differences were also found for the presence of damage from pecan scab [Fusicladium effusum (synonym Cladosporium caryigenum)] and black pecan aphid (Melanocallis caryaefoliae). Most clones were not acceptable for use in Georgia due to small nut size or poor kernel quality, but two clones merit further testing in this region. USDA 70-3-34 produced a large nut with good quality and scab resistance, but needs to be evaluated with mechanical crop thinning to improve kernel quality in high crop-set years. USDA 74-1-12 produced good yields of excellent quality, medium-sized pecans and should be trialed with greater tree numbers. Several other clones were found to have traits of interest to pecan breeding programs including: pecan scab resistance, large nut size, and high kernel percentage. Results of this trial suggest that cultivar development programs in Georgia should place greater selection emphasis on large nut size.

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Comparison of ZnO and ZnSO4 for Correcting Severe Foliar Zinc Deficiency in Pecan

HortScience ◽

10.21273/hortsci.32.1.53 ◽

1997 ◽

Vol 32 (1) ◽

pp. 53-56 ◽

Cited By ~ 1

Author(s):

Bruce W. Wood ◽

Jerry A. Payne

Keyword(s):

Soil Surface ◽

Growing Season ◽

Carya Illinoinensis ◽

Soil Conditions ◽

Zn Deficiency ◽

Surface Zone ◽

Alkaline Soil ◽

Heavy Soil ◽

Kernel Quality ◽

Nut Production

Ground applications of ZnO to large mature pecan [Carya illinoinensis (Wangenh.) K. Koch] trees in orchards possessing an acidic soil, but with a culturally induced slightly alkaline soil surface zone, were at least as effective as was ZnSO4 for rapidly correcting severe foliar Zn deficiency, improving in-shell nut production, and maintaining kernel quality. Under such soil conditions, light disking of Zn applied at 160 kg·ha-1 from ZnO elevated foliar Zn above the sufficiency level by the second growing season after application; whereas an absence of disking delayed substantial uptake from ZnO until the fourth growing season. ZnO, usually a lower priced Zn source, was as effective as was ZnSO4 for correcting Zn deficiencies via broadcast ground application; however, same season correction of Zn deficiency was best accomplished by the standard practice of using foliar sprays of ZnSO4 rather than by heavy soil applications of either Zn source.

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Yield, quality, alternate bearing and long-term yield index in pecan, as a response to mineral and organic nutrition

Notulae Botanicae Horti Agrobotanici Cluj-Napoca ◽

10.15835/nbha48111725 ◽

2020 ◽

Vol 48 (1) ◽

pp. 342-353

Author(s):

Linda C. NOPERI-MOSQUEDA ◽

Juan M. SOTO-PARRA ◽

Esteban SÁNCHEZ ◽

Eloy NAVARRO-LEÓN ◽

Ramona PÉREZ-LEAL ◽

...

Keyword(s):

Productivity Index ◽

Good Strategy ◽

Average Yield ◽

Alternate Bearing ◽

Organic Fertilization ◽

Mineral Fertilization ◽

The World ◽

Nut Production ◽

Yield Quality

The pecan nut is produced in 57 countries in the world. Alternate bearing is one of the main biological problems that affect pecan cultivation. Mineral and organic fertilization is a good strategy to maintain and increase pecan nut production. In this study, several mineral and organic doses of fertilization were tested using a factorial arrangement 56 bounded to 25 treatments was used in structure Taguchi L25: nitrogen (N) 0 - 240 kg ha-1, phosphate (P2O5) 0 - 120 kg ha-1, potassium (K2O) 0 - 100 kg ha-1, calcium (CaO) 0 - 400 kg ha-1, liquid humus 0 - 3600 L ha-1 and solid humus 0 - 8000 kg ha-1. The study was carried out in Aldama city, Chihuahua (Mexico). An average yield of 2.4 t ha-1 was obtained, 157 nuts per kilogram and 58.9% of edible nut. The average alternate bearing intensity was 31.58%, and the long-term yield index (IRLP) was 9.59%. It is concluded that the factors whit the greatest impact on the analyzed variables were N and P2O5. In addition, it was found these mineral and organic fertilization systems help to reduce alternate bearing in pecan and simultaneously improve production and long-term productivity index. Optimal fertilization doses were defined: 181.4 kg ha-1 of N, 93.5 kg ha-1 of P2O5 and 3287.2 L ha-1 of liquid humus. Finally, the mineral fertilization complemented with organic fertilization is considered a good fertilization strategy for pecan trees, to increase production and with lower environmental impact.

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Techniques for Planting Sugarbeet to Advance the Harvest Date in North Indian Conditions

Experimental Agriculture ◽

10.1017/s001447970000346x ◽

1987 ◽

Vol 23 (1) ◽

pp. 99-103

Author(s):

R. S. Narang ◽

B. S. Bains

Keyword(s):

Sugar Beet ◽

Field Study ◽

Direct Seeding ◽

Harvest Date ◽

Sucrose Content ◽

Planting Dates ◽

High Incidence ◽

Northern Side ◽

Early Harvest ◽

East West

SUMMARYResults of a two-year field study show that even under hot northern Indian conditions, sugar-beet planting dates can be advanced to 20 September to permit an early harvest from mid-March onwards. Seeding the crop on the northern side of east-west ridges gave root yields of 45–50 t ha−1 with a sucrose content of 12–14%. Transplanting gave the highest tonnage but led to a high incidence of branched tap roots. For timely planting during October, direct seeding in north–south rows was also satisfactory. Such staggered seeding and harvest schedules could help extend the milling period to 90–100 days as against the present 45–50 days.

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Soil-applied ZnEDTA: Vegetative Growth, Nut Production, and Nutrient Acquisition of Immature Pecan Trees Grown in an Alkaline, Calcareous Soil

HortScience ◽

10.21273/hortsci11467-16 ◽

2017 ◽

Vol 52 (2) ◽

pp. 301-305 ◽

Cited By ~ 2

Author(s):

James L. Walworth ◽

Scott A. White ◽

Mary J. Comeau ◽

Richard J. Heerema

Keyword(s):

Ethylenediaminetetraacetic Acid ◽

Calcareous Soils ◽

Carya Illinoinensis ◽

Additional Benefit ◽

Zn Deficiency ◽

Diameter Growth ◽

Trunk Diameter ◽

The Third ◽

Nut Production ◽

Root Tissues

A field study was conducted to evaluate efficacy of soil-applied zinc (Zn) fertilizer on young pecan [Carya illinoinensis (Wangenh.) K. Koch] trees growing in alkaline, calcareous soils. Chelated Zn ethylenediaminetetraacetic acid (ZnEDTA) was applied at rates of 0, 2.2, or 4.4 kg·ha−1 of Zn via injection into irrigation water (fertigation) in microsprinkler irrigated ‘Western’ and ‘Wichita’ trees. Over the 5-year duration of the study, leaf Zn levels were increased from 22 to 35 µg·g−1 in the highest rate of ZnEDTA treatment compared with 7 to 14 µg·g−1 in unfertilized trees. Zn concentrations in shoot and root tissues were also elevated in Zn-treated trees. Zn treatments largely eliminated visible Zn deficiency symptoms, and increased trunk diameter growth compared with untreated trees. Nut yield (in the third through fifth seasons) were also increased as a result of Zn fertilization. No additional benefit in terms of trunk diameter growth or nut yield was observed by adding a higher rate of Zn (4.4 kg·ha−1) vs. the lower rate (2.2 kg·ha−1). ‘Western’ and ‘Wichita’ trees responded similarly to Zn fertigation.

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Quality Indices and Sensory Scores Support Early Harvest of Pecans

HortTechnology ◽

10.21273/horttech.5.3.208 ◽

1995 ◽

Vol 5 (3) ◽

pp. 208-211

Author(s):

Juan L. Silva ◽

Frank B. Matta ◽

Esteban A. Herrera

Keyword(s):

Fatty Acids ◽

Free Fatty Acids ◽

Shear Force ◽

Carya Illinoinensis ◽

Sensory Properties ◽

Harvest Time ◽

Quality Indices ◽

The Third ◽

Hue Angle ◽

Early Harvest

Pecans [Carya illinoinensis (Wangenh. C.) Koch] were harvested weekly for 9 and 7 weeks until normal harvest time during 1986 and 1987, respectively. Kernels were tested for chemical, physical, and sensory properties. Moisture decreased from 13% at initial harvest time to 4% to 6% by normal harvest. Free fatty acids decreased from 0.5% to 0.2% by the third week before normal harvest. Tannins fluctuated, but averaged about 0.8%. Hue angle remained constant from the fourth week to normal harvest. Shear force increased from 90 to 135 N by the second week before normal harvest. Pecans can be harvested about 2 weeks before normal harvest without significant quality deficiencies.

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Effects of Soil-applied Imazapic on Pecan Production

HortTechnology ◽

10.21273/horttech.20.2.427 ◽

2010 ◽

Vol 20 (2) ◽

pp. 427-430 ◽

Cited By ~ 1

Author(s):

M. Lenny Wells ◽

Eric P. Prostko

Keyword(s):

Arachis Hypogaea ◽

Carya Illinoinensis ◽

Persistent Problem ◽

University Of Georgia ◽

Herbicide Treatments ◽

Southern Georgia ◽

The University ◽

Low Rate

A persistent problem was identified in pecan (Carya illinoinensis) orchards throughout southern Georgia in which pecan trees growing in rows immediately adjacent to peanut (Arachis hypogaea) fields developed hollow pecans. In-shell nut size and appearance was normal; however, the kernels failed to develop. In 2008 and 2009, research was conducted to evaluate the influence of imazapic on pecan nut development in two pecan orchards located at the University of Georgia Ponder Research Farm located near Tifton, GA. Three herbicide treatments were evaluated, including imazapic at 0.17 kg·ha−1, imazapic at 0.30 kg·ha−1, and a nontreated control. Imazapic inhibited pecan kernel production and shuck split during both years of study. In 2009, leaf potassium was reduced by the low rate of imazapic.

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Production Characteristics of the United States Pecan Industry

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.118.4.538 ◽

1993 ◽

Vol 118 (4) ◽

pp. 538-545 ◽

Cited By ~ 4

Author(s):

Bruce W. Wood

Keyword(s):

South Carolina ◽

National Level ◽

The United States ◽

Alternate Bearing ◽

Nut Production ◽

National Production ◽

Practical Tool ◽

Univariate Polynomial ◽

State Production ◽

Highly Correlated

The cyclic, alternate bearing and correlative aspects of U.S. produced pecan [Carya illinoinensis (Wangenh.) K. Koch] nuts are characterized. An attempt to forecast production using stepwise autoregressive techniques identified a national level biennial cycle for cultivar (CV) and seedling (SC) class nuts and a novemennial (9 year) cycle for SG class nuts. The intensity of the biennial cycle at the national level has generally been low to moderate over the last 50 years for CV and SG class nuts with no clear time trend being expressed. During the most recent years (1979-1991), national production of CV class nuts has not exhibited pronounced bienniality, whereas that of SG class nuts exhibited a moderate bienniality. The nature of the the irregularity of cycling of U.S. and state production appears to nullify the use of univariate polynomial equations as a practical tool for accurately forecasting nut production. Nut production within individual states was also cyclic, with 2-, 3-, 5, 6-, 10-, 12-, 14-, 15-, and 16-year cycles, depending on state and nut class. The most intense contemporary biennial cycles for CV class nuts were from Oklahoma, South Carolina, and North Carolina, whereas cycling of SG class nuts was most intense in Texas and Oklahoma. Correlations of production within and among states indicated that most interrelationships are relatively weak; however, national production of CV class nuts are highly correlated (r = 0.96) with the production of CV class nuts in Georgia, whereas that of SG class nuts is most correlated with that of Louisiana.

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Hedge Pruning Pecan

HortTechnology ◽

10.21273/horttech.14.1.0063 ◽

2004 ◽

Vol 14 (1) ◽

pp. 63-72 ◽

Cited By ~ 8

Author(s):

Bruce W. Wood ◽

Deane Stahmann

Keyword(s):

Population Density ◽

Quality Characteristics ◽

Carya Illinoinensis ◽

Attractive Alternative ◽

Alternate Bearing ◽

Tree Population ◽

Commercial Cultivars ◽

Pruning Strategy ◽

Tree Thinning ◽

East West

An ever increasing cost:price squeeze on the profitability of pecan (Carya illinoinensis) farming is driving a search for alternate husbandry approaches. `Wichita' and `Western' trees maintained at relatively high tree population density, by mechanized hedge pruning and topping, produced greater nut yield than an orchard treatment in which tree population density was reduced by tree thinning (144% for `Wichita' and 113% for `Western Schley'). Evaluation of three different hedge pruning strategies, over a 20-year period, identified a discrete canopy hedge pruning and topping strategy using a 2-year cycle, as being superior to that of a discrete canopy hedge pruning and topping strategy using an 8-year cycle, but not as good as a continuous canopy hedge pruning and topping strategy using a 1-year cycle. An evaluation of 21 commercial cultivars indicated that nut yields of essentially all cultivars can be relatively high if properly hedge pruned [annual in-shell nut yields of 2200 to 3626 lb/acre (2465.8 to 4064.1 kg·ha-1), depending on cultivar]. Comparative alternate bearing intensity and nut quality characteristics are reported for 21 cultivars. These evaluations indicate that pecan orchards can be highly productive, with substantially reduced alternate bearing, when managed via a hedge-row-like pruning strategy giving narrow canopies [3403 lb/acre (3814.2 kg·ha-1) for `Wichita' and 3472 lb/acre (3891.5 kg·ha-1) for `Western Schley']. North-south-oriented (N-S) hedgerows produced higher yields that did east-west (E-W) hedgerows (yield for N-S `Wichita' was 158% that of E-W trees and N-S `Western Schley' was 174% that of E-W trees).These data indicate that mechanized hedge pruning and topping offers an attractive alternative to the conventional husbandry paradigm.

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