Shearing is an important cultural practice for maintaining plant size and appearance during nursery crop production. However, oakleaf hydrangea (Hydrangea quercifolia) is susceptible to dieback after shearing. The objective of this study was to determine whether foliar or substrate surface applications of ancymidol or uniconazole can reduce plant growth of oakleaf hydrangea similar to pinching, which was used to simulate shearing. ‘Alice’ or ‘Pee Wee’ oakleaf hydrangea plants were treated in 2002 or 2006, respectively, with ancymidol or uniconazole as a substrate surface application at 0, 1, 2, or 4 ppm; ancymidol as a foliar application at 0, 25, 50, or 100 ppm; or uniconazole as a foliar application at 0, 12.5, 25, or 50 ppm. Both cultivars received the same plant growth regulator treatments in 2012, and a pinched control was included in the 2012 experiment. Ancymidol and uniconazole had limited and inconsistent effects on growth of ‘Alice’ and ‘Pee Wee’ plants regardless of application method. Uniconazole was more effective at controlling growth of ‘Alice’ in 2002 when the study was conducted from October through December than in 2012 when the study was conducted during a more typical growing season of May through September. Plants treated with either ancymidol or uniconazole by either application method usually grew more during the first 2 weeks after application than those that were pinched. During the remainder of the growing season, little difference in growth between pinched plants and growth regulator-treated plants occurred. At harvest in 2012, pinched ‘Alice’ plants had more leaves but a smaller leaf area per leaf than plants treated with growth regulators resulting in no difference in total leaf area or in leaf, shoot, or root dry weight among the treatments. ‘Pee Wee’ treated with uniconazole using either application method or uniconazole as a foliar application had fewer leaves than pinched plants.
Janet C. Cole, Robert O. Brown, and Mark E. Payton
Sandra M. Reed and Lisa W. Alexander
Oakleaf hydrangea ( Hydrangea quercifolia Bartr.; Hydrangeaceae) is a woody shrub native to the southeastern United States, where it grows in calcareous soils in the understory of open woodlands ( McClintock, 1957 ). There are ≈70 species in the
Sandra M. Reed
Oakleaf hydrangea ( Hydrangea quercifolia Bartr.; family Hydrangeaceae Dumort.) is an ornamental shrub that is native to the southeastern United States ( McClintock, 1957 ). Most plants grow 2 m or taller in height with an equal to wider spread
Torin O. Pope and Caula A. Beyl
Agrobacterium rhizogenes is a valuable new tool for inducing adventitious roots in difficult-to-root ornamentals To evaluate species and strain interactions, three ornamental species were chosen: Hydrangea quercifolia, Pyrus calleryana, and Photinia × fraserii. Terminal shoots (2.5 cm long) were collected at bud swelling and then immersed in bleach (20% v/v) for 10 min with stirring. They were rinsed three times in sterile distilled water and cultured individually in test tubes containing 15 ml of Murashige and Skoog medium. After 3 weeks, the uncontaminated shoots were divided into five groups: four strains of A. rhizogenes and a control. There was a significant effect of strain and species in the production of callus and organs from the shoot tips. The presence of strain by host interaction was observed In the morphogenic response of explants.
Jyotsna Sharma and Jim Rich
Plants infected with Meloidogyne spp. (root-knot nematodes) often are stunted and lose aesthetic value due to chlorosis, wilting, and leaf margin necrosis. We assessed reproduction of three root-knot nematode species, Meloidogyne arenaria, M. incognita, and M. javanica, on five plant taxa native to the southeastern U.S. The plant taxa included were: Hydrangea quercifolia `Oakleaf', Viburnum obovatum `Densa', Itea virginica `Little Henry', Illicium parviflorum, and Clethra alnifolia `Ruby Spice'. Three commonly grown non-native shrubs, Ligustrum japonicum `Texanum', Ilexcrenata `Compacta', and Buxus microphylla `Wintergem', also were included in the study to serve as susceptible, positive controls. Highest gall rating (10) was observed on roots of I. crenata `Compacta' infected with M. incognita, but highest number of eggs (6397 eggs/g of roots) was observed in plants of this cultivar inoculated with M. javanica. Few or no galls were observed on roots of the five native plant taxa, and nematode eggs were recovered only from roots of I. virginica `Little Henry' inoculated with M. arenaria and M. javanica (13 and 20 eggs/g of roots, respectively). Fresh weights of shoots or roots were not affected by nematode inoculation. Due to lack of root gall development and little or no reproduction on the native taxa, we conclude that these are resistant or immune to the three species of Meloidogyne and might be suitable for planting in infested soil.
Muhammad Irshad, Hafiz Muhammad Rizwan, Biswojit Debnath, Muhammad Anwar, Min Li, Shuang Liu, Bizhu He, and Dongliang Qiu
adventitious shoot production from Hydrangea quercifolia Bartr. leaf explants Scientia Hort. 101 121 126 Lorenzo, J.C. de los Angeles Blanco, M. Peláez, O. González, A. Cid, M. Iglesias, A. González, B. Escalona, M. Espinosa, P. Borroto, C. 2001 Sugarcane
Susmitha Nambuthiri, Ethan Hagen, Amy Fulcher, and Robert Geneve
since been employed successfully on a number of crops including Hibiscus rosa-sinensis ( Fulcher et al., 2012 ), oakleaf hydrangea ( Hydrangea quercifolia ) ( Hagen et al., 2014 ), and redbud ( Cercis canadensis ) ( Nambuthiri et al., 2015a ) without
Robert F. Brzuszek, Richard L. Harkess, and Susan J. Mulley
( Myrica spp.), yaupon holly ( Ilex vomitoria ), southern magnolia ( Magnolia virginiana ), live oak ( Quercus virginiana ), oakleaf hydrangea ( Hydrangea quercifolia ), red maple ( Acer rubrum ), bald cypress ( Taxodium spp.), flowering dogwood ( Cornus
Robert F. Brzuszek, Richard L. Harkess, and Lelia Kelly
( Rhododendron spp.), oak-leafed hydrangea ( Hydrangea quercifolia ), purple cone flower ( Echinacea purpurea ), butterflyweed ( Asclepias spp.), iris ( Iris spp.), black-eye-susan ( Rudbeckia spp.), eastern redbud ( Cercis canadensis ), and flowering dogwood
Stefan B. Lura and Alan T. Whittemore
propagations of 850089A.) Hydrangea quercifolia ‘Queen of Hearts’ . Registered on 28 Aug. 2014. Registrant: Dr. Margaret Pooler, U.S. National Arboretum, 3501 New York Ave. NE, Washington, DC 20002, USA. Hydrangea quercifolia ‘Queen of Hearts’ (NA 79748; PI