Search Results

You are looking at 1 - 10 of 31 items for

  • Author or Editor: Patrick J. Conner x
  • Refine by Access: All x
Clear All Modify Search
Free access

Patrick J. Conner

Storage of pollen from 1 year to the next is often needed to enable desired crosses to be made in a pecan [Carya illinoinensis (Wangenh.) K. Koch] breeding program. Stored pollen is usually tested for viability through the use of in vitro germination tests. An in vitro germination testing system was developed for this purpose using cellophane booklets to provide a solid support for the pollen grains. Optimized germination media contained 5% sucrose, 20% polyethylene glycol 8000, 0.05% Ca(NO3)2, 0.025% H3BO3, and 10 mm 2-(N-morpholino)ethanesulfonic acid pH 6.0. Pollen should be rehydrated for 2 to 4 h in a humidified chamber before germination testing. A germination time of 4 to 24 h produces similar final germination percentages. Testing of pollen samples stored at –80 °C indicates that pecan pollen can be stored for at least 8 years without a decrease in viability. Chemical names used: polyethylene glycol (PEG); 2-(N-morpholino)ethanesulfonic acid (MES).

Free access

Patrick J. Conner

‘Hall’ is a self-fertile bronze-colored muscadine grape (Vitis rotundifolia Michx.) that is being released by the University of Georgia (UGA) College of Agriculture and Environmental Sciences. ‘Hall’ produces good yields of medium- to large-sized berries with excellent taste suitable for the fresh market. ‘Hall’ berries have exceptionally low levels of pedicel scar splits and tears, leading to a high percentage of usable berries. ‘Hall’ has an early harvest date with an average first pick of 31 July in Tifton, GA. Berry color of ‘Hall’ is noticeably brighter and more yellow than most bronze cultivars. ‘Hall’ is recommended as

Open access

Patrick J. Conner

‘RubyCrisp’ is a muscadine grape (Vitis rotundifolia) that was released by the University of Georgia (UGA) College of Agriculture and Environmental Sciences (Athens, GA). ‘RubyCrisp’ produces high yields of large-sized berries with excellent taste and texture. ‘RubyCrisp’ berries are dark red in color, which is distinct from the normal bronze and dark purple colors of most muscadine cultivars. ‘RubyCrisp’ has hermaphroditic flowers and produces berries of similar size to those of the largest female cultivars (≈15 g). ‘RubyCrisp’ has a midseason harvest date with an average first pick on 21 Aug. in Tifton, GA. ‘RubyCrisp’ has a low

Free access

Patrick J. Conner

A detached leaflet protocol was developed for the evaluation of resistance to Fusicladium effusum in a seedling pecan population segregating for resistance. Leaflets at half to full expansion were detached from seedling trees, sprayed with a conidial suspension (isolate De-Tif-3), placed in a polyethylene bag in a growth chamber, and evaluated microscopically 7 and 14 days after inoculation. The percentage germinated conidia producing subcuticular hyphae was the best determinant of susceptibility with genotypes producing more than 15% subcuticular hyphae considered susceptible. Leaflets at half expansion had higher percentages of subcuticular hyphae and gave a clearer separation between susceptible and resistant genotypes than leaflets at full expansion. An evaluation period of 14 days was preferable to 7 days to allow slower reacting genotypes to be better evaluated. The detached leaflet protocol was evaluated in contrasting environments and was found to be robust to differences in shading and leaflet wetness. Detached leaflet tests gave similar results to field inoculations but were superior in consistently detecting susceptible genotypes. This protocol will be useful in evaluating the inheritance of pecan leaf scab resistance in breeding progenies.

Free access

Patrick J. Conner

‘Paulk’ is a hermaphroditic muscadine grape (Vitis rotundifolia Michx.) with black berries that was released by the University of Georgia (UGA) College of Agriculture and Environmental Sciences. ‘Paulk’ produces high yields of large-sized berries with excellent taste suitable for the fresh market. ‘Paulk’ is the first cultivar with hermaphroditic flowers that produces berries of similar size to the largest female cultivars (≈15 g). ‘Paulk’ produces a high percentage of usable berries with low incidences of berry rot or pedicel scar splitting. ‘Paulk’ has a midseason harvest date with an average first pick on 20 Aug. in Tifton, GA.

Free access

Patrick J. Conner

Twenty-six muscadine grape (Vitis rotundifolia Michx.) cultivars and selections were evaluated for a range of skin and flesh texture attributes. Two Vitis vinifera L. and one Vitis labruscana Bailey table grape cultivars were included for comparison. Penetration tests using a flat cylindrical probe were used to assess whole berry texture. Ideal whole berry texture is firm and easily broken down during mastication, which was measured as small berry deformation at first peak and berry maximum force, respectively. Muscadine berry deformation at first peak ranged from 4.35 to 7.82 mm and berry maximum force ranged from 5.7 to 13.9 N. V. vinifera table grape berries were firmer (3.14 to 3.19 mm berry deformation at first peak) and more tender (4.0 to 4.9 N berry maximum force) than muscadine berries. Berry penetration work was strongly correlated with both berry deformation at first peak and berry maximum force and ranged from 13.0 to 54.1 mJ in the muscadine germplasm. Penetration tests of muscadine berry flesh revealed a range of flesh firmness from very soft (0.65 N) to firm (3.06 N) but none was as firm as the V. vinifera berry flesh (3.9 N). Penetration tests of muscadine berry skins revealed newer selections bred for table use had relatively tender skins with a skin break force of 12.1 N, which was not different from V. vinifera samples. Berry penetration work and flesh maximum force were determined to be the most useful characteristics for routine screening of breeding program material.

Open access

Patrick J. Conner

‘Kalos’ is a new pecan (Carya illinoinensis) cultivar released by the University of Georgia College of Agriculture and Environmental Sciences. ‘Kalos’ produces good yields of large, high-quality pecans. ‘Kalos’ matures in early October in southern Georgia. Nuts produced by ‘Kalos’ are easily shelled into complete halves, and the kernels have a light golden color. ‘Kalos’ has moderate resistance to pecan scab (Venturia effusa), with low levels of disease symptoms in orchards using fungicides to control this disease. ‘Kalos’ is recommended for planting in the southeastern United States in orchards that will receive fungicide applications.

Origin

In

Free access

Patrick J. Conner

A detached leaf screening technique was developed for studying specific interactions between pecan [Carya illinoinensis (Wangenh.) C. Koch] cultivars and isolates of the pecan scab fungus, Cladosporium caryigenum. Monoconidial isolates were obtained from leaf scab lesions on `Wichita', `Desirable', `Cape Fear', and `Elliot'. Each isolate was then inoculated onto detached leaves of each of the four cultivars and fungal growth was observed under the microscope after eight days. `Wichita', `Desirable', and `Cape Fear' isolates produced subcuticular hyphae at a much higher frequency when inoculated back onto the cultivar from which they were isolated in comparison to the other cultivars. The `Elliot' isolate was able to produce a high frequency of subcuticular hyphae when inoculated onto `Elliot' and `Cape Fear', but not when inoculated onto `Desirable' and `Wichita'. Field inoculations conducted with the `Wichita' and `Desirable' isolates validated the detached leaf protocol. The results obtained indicate that pecan scab is composed of multiple races with a high degree of specificity for host cultivars. A rapid whole-leaf staining system is presented which appears to have wide applicability to assessing fungal growth in leaves.

Free access

Patrick J. Conner

The genus Vitis L. contains two subgenera, Euvitis Planch. (bunch grapes) and Muscadinia Planch. (muscadine grapes). The muscadine grape, Vitis rotundifolia Michx., is the only commonly cultivated member of the Muscadinia subgenus. The muscadine grape differs from the common bunch grape (Vitis labrusca L., V. vinifera L., and their various hybrids) by the presence of smaller clusters, unbranched tendrils, berries with thick skins, and a unique fruity aroma. Muscadine grapes are an important fruit crop in the southeastern United States where Pierce’s disease (Xylella fastidiosa

Free access

Patrick J. Conner

‘Avalon’ is a new pecan [Carya illinoinensis (Wangenh.) K. Koch] cultivar that was released by the University of Georgia (UGA) College of Agriculture and Environmental Sciences. ‘Avalon’ produces high yields of large nuts with good quality that mature in early October in south Georgia. Compared with most other cultivars with similar nut size and quality, ‘Avalon’ has superior resistance to pecan scab [Venturia effusa (G. Winter) Rossman & W. C. Allen (basyonym Fuscladium effusum)]. High levels of resistance to this devastating disease make ‘Avalon’ especially suitable to planting in the southeastern U.S. where frequent