Thesis (Ph. D.)--North Carolina State University, 2004. / Includes vita. Originally issued in electronic format. UMI number: 3137112. Includes bibliographical references (p. 151-159). Also available via the World Wide Web.

Unlike Sweden, Denmark is a major industry when it comes to christmas tree cultivation. More than ten million christmas trees are processed in Denmark annually. The primary purpose of this report is to investigate the technology, treatment and maintenance of christmas trees in Sweden and Denmark, and to find differences in the management between Swedish and Danish christmas tree cultivators. Since an opinion poll has been made, the investigation method mainly used for this report is quantitative. But a qualitative investigation method has also been used to some extent as a few unstructured interviews has occurred while visiting a couple of the cultivators.   63 % of the christmas tree cultivators consider themselves knowledgeable about christmas tree cultivation and 68 % wants to learn more. There is both similarities and differences along those cultivators that has been visited. Obvious similarities has mostly been found when visiting farms engaged in developing christmas trees to a bigger extent. Denmark conducts their maintenance methods with the aim to produce a large amount of high quality Christmas trees. This tendency does also occur in Sweden at, for example, Gunnars Granar located in Degeberga. Gunnar manages his cultivation almost identically to Denmark's management methods. However, the big christmas tree cultivators are still mainly located in Denmark.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1990. / Vita. Abstract. Includes bibliographical references (leaves 73-77). Also available via the Internet.

Vad hindrar svensk julgransodling från att växa och bli en egen näring på motsvarande vis som i Danmark. Den svenska julgransmarknadens storlek har undersökts och det har visat sig att den är mindre än man tidigare trott. En stor del av skogsägarna säger sig vara intresserade av julgransodling och bedömer lönsamheten som högre än i traditionellt skogsbruk. Skogsägarna upplever svårigheter med att klara av skötsel på grund av att den är tidskrävande och att dessa tjänster inte finns tillgängliga på marknaden. Ytterligare ett hinder upplevs vara att nå ut till marknaden och få betalt för kvalitetsprodukter. En skillnad jämfört med Danmark där julgransodling är en exportindustri är att det finns en aktiv branschorganisation, utbildning, kompetens och företag som säljer maskiner och tjänster till näringen. Baserat på intervjuer med producenter, grossist och detaljister verkar prisnivån vara densamma för svenska odlare som för danska med korrigering för logistikkostnader. Kalkylräntan som beräknads med nuvärdesprincipen landade på 11,4%.

The goal of this thesis is to derive an accurate confidence interval after a sequential test with Christmas tree boundaries. We shall begin with an approximate pivot based on signed-root transformation, then apply the procedure of Weng and Woodroofe [2000] to derive an improved confidence interval. Accuracy of the theoretical result is investigated by simulations.

This dissertation argues that from 1880 to 2010 the American natural and artificial Christmas tree industries remodeled themselves after one another. Artificial tree companies modeled their products after the natural tree, hoping to make them look, smell, and feel like the real thing. As these replica trees became popular, scientists, extension agents, and farmers worked to control the natural Christmas tree crop unlike ever before. Those efforts stemmed from a desire to wrest from nature the same kind of idealized silhouettes their plastic counterparts celebrated. Both industries tried to convince the country’s consumers to buy what they were selling. Through Americans’ shifting Christmas tree experience, this dissertation highlights the evolution of particular cultural and environmental ideas. It reveals how both the natural and artificial tree industries intentionally misled the public about the ecological implications of their businesses. Further, it demonstrates that although many Americans believed that the natural Christmas tree ritual could instill the children’s youth with an appreciation of the outdoors or the value of the hard work symbolized by the felling of a tree and dragging it into the living room, by the 1960s such an outlook became contested unlike ever before. As fake tree companies promised convenience, many citizens looked upon their ersatz tree as a symbol of progress and good environmental stewardship just as others worried that modernity would alienate the nation’s youth from the wild spaces and hard work of their ancestors. This dissertation also considers how gender animated the trade by showing how farmers frequently blamed the nation’s women for their reliance on pesticides. That chemical dependency, farmers maintained, was the only way to grow the shapely trees the nation’s women supposedly demanded. Growers also trivialized the work of women within the business in an effort to bolster their own masculine image. As the crop spawned festivals in some communities, locals equated tree bodies with those of women, overtly implying that beauty was most important in both.

The process of diagnosing the foliar nutrient status of Fraser fir [Abies fraseri (Pursh)Poir.] Christmas trees and prescribing fertilizers is not well understood. Agricultural researchers have established critical yield levels for agronomic crops that are objective measures of crop quality and have associated these yields with nutrient status; however, Christmas tree quality is subjective and not well associated with nutrient status. A nutrient-sensitive tree response factor that reflects tree quality is needed for a proper diagnosis. The purpose of this study was to determine the relationship between nutrient balance and indices of tree quality and to evaluate how nutrient balance and tree quality can be manipulated by fertilizer inputs based on the Diagnosis and Recommendation Integrated System. In 1984 a factorial N, P, pH, fertilizer source, and fertilizer frequency trial was installed in northwestern North Carolina. A randomized complete block design with factorial combinations of all five factors was used. After three years, the fertilizer trial was analyzed to study the effects of fertilizer additions on foliar nutrient balance and tree quality. Several tree response factors were measured in the fall after dormancy. Statistical methods such as correlations and multivariate discriminant analysis were used to determine which response factors were correlated with foliar nutrients and which factor most governed tree quality. DRIS indices were calculated for six independent plots of different fertility treatments. Basal diameter (BD) was the strongest discriminator of tree quality and was used as a substitute for yield in the DRIS analyses. The importance of nutrient intensity was demonstrated since significant nutrient / dry matter ratios were calculated for N, P, K, and Mg. Balance was shown to be important since the indices for N, K, and Mg were a function of the four other nutrient ratios other than dry matter, and the P and Ca indices were a function of three nutrient ratios other than dry matter. Nutrient balance was also shown to be important by the significant relationship of BD as a function of the nutrient balance index (NBI). When NBI had a relatively small value, large BD trees were produced; as NBI values increased, BD decreased. Fertilizer additions that created nutrient imbalances also decreased BD, in spite of the high nutrient intensities found in the foliage. These results show that nutrient balance in Fraser fir foliage, as well as nutrient intensity, is important for producing optimal Christmas tree quality. / Master of Science

Thousands of sexual assault cases in the United States are backlogged. This has been a growing issue for years that has increased the difficulty of solving these cases and providing closure to the victims. The analysis process for each case includes the identification of body fluids, presumptive testing, confirmatory testing, and DNA extraction. The only confirmatory method for semen identification is a microscopic visualization of sperm cells. The time spent on microscopic analysis varies depending on the complexity of the samples and the skills of the analyst. While the identification of sperm cells is informative, it can be very time-consuming and labor intensive. Some forensic laboratories choose to skip this step and submit samples directly for DNA analysis. Conducting DNA analysis on unscreened samples can increase the cost of testing when negative samples are analyzed as well as the time it takes to process each case. Automated microscopy has been available for decades and more recently has been paired with artificial intelligence to detect sperm cells on microscope slides. In this research, the MetaSystems automated microscope was used to analyze slides that mimic forensic sexual assault samples. Slides were also examined using traditional microscopy. The automated system quickly provided an accurate quantification of the number of sperm cells present in a sample, which can inform downstream DNA testing. The software was successful in identifying sperm cells treated with Christmas tree and hematoxylin and eosin stains, even among epithelial cells and various contaminants. Results demonstrated that an artificial intelligence-driven forensic sperm cell detection microscope can significantly reduce the time it takes to locate and identify sperm cells and estimate sperm cell quantity compared to a lengthier and more tedious manual search. Drawbacks to the system include the relatively high cost and reduced ability to accurately detect sperm cells amid contaminants that are of similar morphology.

Fraser fir [Abies fraseri (Pursh) Poir.] is an important Christmas tree species in Virginia. Because it is responsive to fertilization, and because most Fraser fir growers fertilize their crop, a scientifically-based nutrient diagnosis and fertilizer recommendation system is needed. The objective of this study was to develop and test DRIS norms for Fraser fir Christmas trees grown in Virginia for the ultimate purpose of establishing a nutrition diagnosis and fertilizer prescription system. A total of 107 Fraser fir plantations were sampled for foliage, soil, and diameter measurements. These plantations represented the range in site conditions and management practices for Fraser fir Christmas trees grown in Virginia. Foliage was analyzed for N, P, K, Ca, Mg, Zn, Mn, Fe, Cu, and B. Soil was analyzed for extractable macro- and micronutrients. DRIS norms were developed from these data using standard DRIS procedures. A total of 42 nutrient ratios were significant discriminators of tree performance as measured by variation in ground line diameter. The norms were tested using sixth year data from a factorial fertilizer trial. Nutrient limitations due to both deficiencies and imbalance were detected and correctly diagnosed using the newly-derived norms. A complete validation is required, but this preliminary test showed that these norms are useable and useful in their present form. In the process of developing and testing the norms, modifications to traditional DRIS methods were used to meet the special conditions of this crop. DRIS symmetry was maintained by including non-significant ratios, but setting their standardization functions equal to zero. This reduced the influence of the non-discriminating nutrient ratios on the DRIS analysis. Norm ranges as opposed to discrete norms (ratio means) were used to correct for the influence of extremely variable micronutrient ratios on the DRIS analysis. Soil norms did not enhance diagnoses over and above using foliar norms alone. This is due to soil sampling variation, poor correlations of extractable nutrients with tree performance, and an incomplete understanding of fertilizer reactions and uptake chemistry in a variety of soils. Each crop presents unique challenges in the application of DRIS. DRIS should not be naively applied without investigating these problems. The DRIS norms established in this study, and the modifications to standard DRIS methods, provide a sound scientific basis upon which to build a nutrient diagnosis and fertilizer recommendation system for Fraser fir Christmas trees grown in Virginia. / Master of Science

Procerum root disease (PRD), caused by Leptographium procerum (Kendr.) Wingf., is the most serious problem facing Christmas tree growers of eastern white pine, (Pinus strobus L.). Limited studies have shown an association between PRD affected trees and insect infestations, and L. procerum has been recovered from field collected insects. The objectives of this study were to demonstrate the association of L. procerum with the life cycle of potential insect vectors and determine if the insect associates could transmit the fungus to healthy trees. To study the association of PRD with potential insect vectors, PRD symptomatic trees from 4 Christmas tree plantations were excavated and examined monthly, June - September in 1988 and 1989, and April - September 1990. Potential insect vectors were collected weekly in baited pit-fall traps placed in: 1) paired plots placed in asymptomatic and symptomatic areas of PRD symptomatic plantations, 2) plots in plantations where PRD was absent, 3) plots in the headlands of plantations, 4) plots in forested areas and 5) one plot in an urban setting. Trees in the plots were also inspected for evidence of weevil feeding and for development of PRD. Larvae of two weevil species, Hylobius pales (Herbst.) and Pissodes nemorensis Germ., were recovered from 52, 42, and 43% of PRD symptomatic eastern white pine in 1988, 1989, and 1990, respectively. Hylobius pales and P. nemorensis contaminated with L. procerum were recovered from all plots. The proportion of H. pales contaminated with L. procerum was 73.0% in 1988, 86.5% in 1989 and 72.9% in 1990 while the proportion of P. nemorensis contaminated with the fungus was 17.8, 21.2 and 14.2% in 1988, 1989 and 1990, respectively. Over the three year period of the study, the proportion of PRD infected trees in the symptomatic paired plots rose from 3.6 to 29%. None of the trees in the asymptomatic plots became symptomatic. Transmission of L. procerum was determined by caging field collected and artificially infested H. pales and P. nemorensis on eastern white pine seedlings for 24 hours. To determine if transmission of the fungus during oviposition leads to contamination of the brood,field collected H. pales adults were allowed to feed and oviposit on fresh white pineee bolts. Feeding by artificially infested H. pales adults resulted in transmission of L. procerum 90 and 98% of eastern white pine seedlings in 1989 and 1990, respectively. Field collected H. pales adults transmitted the fungus to 58 and 68% of seedlings in 1989 and 1990, respectively. Artificially infested and field collected P. nemorensis adults transmitted L. procerum to 100 and 28% of the seedlings respectively. All bolts oviposited on by field collected H. pales became colonized by L. procerum and 100% of the weevils that emerged from them were contaminated with the fungus. The results from this study confirms the rules for insect transmission of a plant pathogen. / Ph. D.