Browsing by Author "John Frampton, Committee Member"

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Adventitious Rooting and Physiology of Stem Cuttings of Loblolly Pine
(2005-04-13) LeBude, Anthony Vincent; Farrell C. Wise, Committee Member; Barry Goldfarb, Committee Co-Chair; John Frampton, Committee Member; Frank A. Blazich, Committee Co-Chair
Vegetative propagation by stem cuttings can be used to multiply improved seedlings of timber species before deployment for reforestation. Before full scale deployment of rooted stem cuttings can be accomplished on an operational level, however, various obstacles need to be overcome. Among these obstacles are development of rooted cutting production systems and effective control of the rooting environment to stimulate adventitious root formation. Therefore, two separate series of experiments were conducted to develop protocols for clonal propagation of loblolly pine (Pinus taeda L.) by stem cuttings. The first series of experiments were conducted to test the efficacy of two containerized production systems on rooting percentage, root system morphology, and first year field growth of rooted stem cuttings of loblolly pine. The second series of experiments focused on the effect of the rooting environment on adventitious root formation to define a propagation protocol with broad application that stimulates rooting among several rooting environments. In the first series of experiments, three studies were conducted to test adventitious rooting of juvenile hardwood (dormant) or softwood (succulent) stem cuttings of six unrelated full-sib families of loblolly pine in various sizes of Jiffy® Forestry Peat Pellets or Ray Leach Conetainers™ and the subsequent effect on first year field growth after outplanting. Controls in all experiments were Ray Leach Super Cells filled with a medium of 2 peat : 3 perlite (v/v). After adventitious rooting in the greenhouse and 12 months of field growth, all plants, with the exception of plants produced in one Jiffy pellet size, were shorter than the controls and had less root dry weight (DW) and shoot DW. Results suggest that preplant root DW is an important predictor of first year field performance. Therefore, cuttings rooted in pellets may need to be transplanted to a nursery bed for further root growth and development prior to field planting. Rigid plastic containers remain a viable production system because cuttings rooted consistently, had large root mass, and plants were of commercial size after 1 year of field growth. In the second series of experiments, six studies were conducted. Four studies investigated the influence of cutting water potential (Ψcut) on rooting of juvenile dormant and succulent stem cuttings of loblolly pine propagated under varying substrate water potentials (Ψsub) and volumes of mist application (mist levels). In the first two studies, mist level and Ψsub contributed to the Ψcut of nonrooted stem cuttings. In the second two studies, when Ψsub was held constant across various mist treatments, mist level contributed strongly to Ψcut. In the first two studies, Ψsub affected rooting percentage when mist was suboptimal or excessive; otherwise, mist had a stronger effect than Ψsub on rooting percentage. For all four studies, cuttings rooted best when experiencing moderate water deficits (- 0.5 to - 1.2 MPa) during the period of adventitious root formation. Results demonstrate that monitoring the physiological status of stem cuttings during adventitious rooting can provide important information for controlling the rooting environment. The final two studies of the second series of experiments investigated the relationships between mist application, vapor pressure deficit (VPD), Ψcut, and rooting percentage of dormant or succulent stem cuttings of loblolly pine. In addition, net photosynthesis at ambient conditions (Aambient) and stomatal conductance (gs) of succulent stem cuttings were measured during adventitious root formation to determine their relationship to rooting percentage. Dormant stem cuttings rooted ≥ 80% when mean daily VPD between 1000 and 1800 HR ranged from 0.60 to 0.85 kPa. Although rooting percentage was related to Ψcut and gs, and Aambient was related to Ψcut and gs, rooting percentage of succulent stem cuttings was not related to Aambient. Using VPD as a control mechanism for mist application during adventitious rooting of stem cuttings of loblolly pine might increase rooting percentages across a variety of rooting environments.
Biological Control, Host Resistance, and Vegetative Propagation: Strategies and Tools for Management of the Invasive Hemlock Woolly Adelgid, Adelges tsugae Annand.
(2008-09-04) Jetton, Robert Miller; David Orr, Committee Member; John Frampton, Committee Member; John Monahan, Committee Member; Fred Hain, Committee Chair; Dan Robison, Committee Co-Chair
Developing Artificial Rearing Techniques for Hemlock Woolly Adelgid, Adelges tsugae and Balsam Woolly Adelgid, Adelges piceae; Artificial Infestation and Epicuticular Wax Study of Carolina Hemlock, Tsuga caroliniana, Provenances.
(2008-12-23) Kaur, Navdip; John Frampton, Committee Member; John F Monahan, Committee Member; Fred P Hain , Committee Chair
Adelges tsugae Annand, the hemlock woolly adelgid (HWA), is an exotic pest of hemlocks that is a threat to the health and sustainability of hemlocks in the eastern United States. Hemlocks (Tsuga spp.) are one of the most important ecological, economic and aesthetic tree species of the eastern US. In order to save hemlocks an intensive research effort on HWA is underway. The objective of this study was to develop an artificial diet for HWA and to determine, if there are differences in adelgid infestation rates and fecundity among eight provenances of Carolina hemlock. Sixteen diets were prepared and were tested in liquid, solid and cellular forms to determine their suitability for adelgid development. In addition, feeding and delivery systems were developed to provide fresh diet continuously. All the liquid based diets showed no significant differences and no diet uptake except the MDB-1 and MDB-3 diets. BWA crawlers were able to survive for two weeks on these two diets. The 1st instars survived for 10-12 days on these diets whereas their survival was not more than 3-4 days on other diets. Solid based diets did not show any encouraging results and all the crawlers stopped their activity in 3-4 days on these diets. Digestive track dissection of the HWA suggested the cellular nature of their diet and subsequent cellular based diets allowed 10-15% of the crawlers to develop to 2nd instars, and the2nd instar survival was also high. Amylase tests on the HWA saliva showed very week amylase activity probably from the presence of microorganisms in HWA gut. Variation among Carolina hemlock was observed with respect to infestation rate and fecundity. The infestation level (number of eggs/woolly mass) for the provenances from Caeser head Campground and Crabtree was significantly higher than Wildcat and Table rock, and no infestation was seen in Bluff Mountain, Linville and Cradle provenances. Insects respond to many chemical cues for feeding that can be responsible for susceptibility and resistance of the host. The epicuticular wax was analyzed by GC/MS and linked to the host preference of HWA. Hexacosanol was observed in all the provenances, however the concentration of hexacosanol with other chemicals seems to be dependent on insect infestation. Some other chemicals are also found, which are either deterrents or stimulants in other insects but their role in HWA and hemlock species is not known.
Predatory Mites (Acari: Phytoseiidae) in Fraser fir Christmas Tree Plantations in the Southern Appalachians of North Carolina
(2008-07-07) Williams, Jay Logan; David Orr, Committee Member; John Frampton, Committee Member; John Monahan, Committee Member; Fred P. Hain, Committee Chair
Production System Influences the Survival and Morphology of Rooted Stem Cuttings of Loblolly Pine (Pinus taeda L.) and Sweetgum (Liquidambar styraciflua L.)
(2006-05-15) Gocke, Matthew Harrison; Frank Blazich, Committee Member; John Frampton, Committee Member; Barry Goldfarb, Committee Co-Chair; Daniel J. Robison, Committee Co-Chair
Forest planting stock must be capable of high rates of survival and good field performance to justify the expense of reforestation efforts. Seedling grading standards have improved the quality of forest planting stock and have increased expectations for survival and field growth of out-planted forest seedlings. For many tree species, rooting stem cuttings provides an alternative means of producing planting stock to that of conventional seedling propagation. Use of rooted stem cuttings (rooted cuttings) in forestry has many potential advantages for both research and operational applications. However, to realize these benefits, it is important that high quality rooted cuttings are produced to enable field performance on par with seedlings of the same species and similar provenance. Developing specific grading standards for rooted cutting planting stock, therefore, is critical for successful field performance, and, is a topic of increasing interest for clonal forestry of particular species. Grading standards for rooted cuttings may differ from those of seedlings, because of potential biological differences and increased production costs for rooted cuttings. Furthermore, various production systems exist capable of producing high quality rooted cutting planting stock and may require individual grading standards. Loblolly pine and sweetgum, to a lesser degree, are two commonly out-planted forest tree species in the southeastern United States. Seedling grading standards exist for both species in this region. Increased interest in clonal propagation of loblolly pine and sweetgum requires development of rooted cutting grading standards to ensure high rates of survival and good field performance. Two studies conducted in 2000 and 2001 investigating rooted cutting production systems for loblolly pine and sweetgum are described in the following two chapters. The effects of a transplant, a containerized, and a direct-stick production system on morphological characteristics of loblolly pine rooted cuttings were evaluated in the first chapter. Morphological comparisons were made among the various stock types tested. In the second chapter, feasibility and morphological effect of a transplant, a containerized, and a direct-stick rooted cutting production system were evaluated for sweetgum. Semi-hardwood (SH) stem cuttings of sweetgum were tested in all three production systems with special emphasis placed on the presence of new shoot growth following rooting. Hardwood (H) stem cuttings of sweetgum were also rooted in a direct-stick system in an outdoor nursery bed to test the reported ability of this cutting type to produce new shoot growth in the same season as rooting. Rooted cutting morphology varied among clone and production system for both loblolly pine experiments. By the second loblolly pine experiment, over 90% of the rooted cuttings produced in the systems tested met acceptable seedling grading standards, including the second cycle (May sticking). Results of this study demonstrated that all three production systems evaluated were capable of producing high quality planting stock and that two full production cycles can be obtained in one growing season in the containerized and transplant systems. All four production systems evaluated in the sweetgum study produced rooted cuttings. Morphological measurements varied among these same rooted cuttings according to production system. The transplant and containerized systems produced a large number of rooted cuttings with high rates of survival and large root systems. The SH direct-stick system produced rooted cuttings with sizeable root systems, but proved more sensitive than the other systems tested. A SH direct-stick system requires a back up irrigation system and a secondary power source to be effective. The H direct-stick production system was the only system to produce rooted cuttings exhibiting substantial shoot growth during the first growing season. Some of these rooted cuttings also developed extensive root systems, but survival was low.