Treesearch

Insects require sterols for normal growth, metamorphosis, and reproduction, yet they are unable to synthesize these organic compounds and are therefore dependent upon a dietary source. For phloephagous species, such as Dendroctonus bark beetles, whose food does not necessarily contain appropriate types or adequate quantities of sterols, fungal symbionts may provide an alternative source in the form of ergosterol. We determined and compared the relative amounts of ergosterol in the primary fungal associates of Dendroctonus ponderosae Hopkins and Dendroctonus rufipennis Kirby. Ergosterol...

Conventional fertilization in nursery culture of hardwoods may involve supply of equal fertilizer doses at regularly spaced intervals during the growing season, which may create a surplus of available nutrients in the beginning and a deficiency in nutrient availability by the end of the growing season. A method of fertilization termed “exponential nutrient loading” has been successfully used in propagation of several conifer species, but this technique has not been tested in hardwood culture. By supplying fertilizer nutrients in an exponential manner, nutrient supply more closely matches...

At the George O. White State Forest Nursery in Licking, MO, we annually grow about 20 species of shrubs. That number has been larger in some years. For most species, we purchase seeds locally and process them at our nursery. Our shrubs are used for wetland restoration, windbreaks, visual screens, riparian buffers, and wildlife plantings.

The USDA Forest Service National Seed Laboratory has provided seed technology services to the forest and conservation seed and nursery industry for more than 50 years. This paper briefly traces the lab’s evolution from a regional facility concerned principally with southern pines to its newest mission as a national facility working with all native U.S. plants and serving national and international needs.

Shortleaf pine (Pinus echinata Mill.) seeds collected from several half-sib families were grown as both container and bareroot stock and outplanted in two tests at the George O White Nursery in Licking, Missouri. After eight growing seasons, 2-year-old container seedlings had significantly better survival than 2-year-old bareroot seedlings, while survival of the 1-year stocktypes was not significantly different. Two-year-old container seedlings had 52 percent higher survival than 2-year-old bareroot stock. Two-year-old bareroot seedlings had greater stem diameter and volume growth than the...

In July 2004, a large stand of red oak (Quercus rubra) was harvested in Phelps Township, North Bay District, North Bay, Ontario using the uniform shelterwood system. Most of the stand was harvested to retain 40 percent crown closure, while a very small portion was harvested to retain 70 percent crown closure. During tree marking, an active Northern Goshawk (Accipiter gentilis) nest was identified and the appropriate Area of Concern (AOC) prescription was applied. Within the modified cut portion of the AOC, the group selection silvicultural system was used with two different size group...

The most recent computer program upgrade for the nursery was completed in 1992. It was time for a change. Technology changes at a rapid pace, and a 12-year-old program could use improvement. The nursery program went through a total overhaul. This paper outlines steps taken to complete this process.

Tree nurseries, by their very nature, provide key components of the disease triangle (pathogen, host, and environment) simply by the widespread planting of susceptible host(s) grown under optimal conditions. Pathogens can severely impact the quality and quantity of seedling stock, making pest management a high priority in successful nursery practice. Careful inspections for symptoms and signs of fungal agents can improve the precision of cultural, chemical, and biological management strategies, as well as alert growers to newly emerging pests of concern. The purpose of this presentation is...

This paper discusses the potential to use X-ray image analysis as a rapid and nondestructive test of viability of northern red oak (Quercus rubra L.) acorns and the methodology to do so. Acorns are sensitive to desiccation and lose viability as moisture content (MC) decreases, so we examined X-ray images for cotyledon damage in dried acorns to predict seed viability and early seedling growth. When compared to greenhouse growth measurements, the X-ray image analysis proved to be related to seed germination and early seedling growth, even more so than MC. These results suggest that X-ray...

This paper reviews general literature, research studies, field observations, and standard Forest Service survival surveys of high-elevation whitebark pine plantations and presents a set of guidelines for outplanting prescriptions. When planting whitebark pine, the recommendations are: 1) reduce overstory competition; 2) reduce understory vegetation, especially grasses and sedges; 3) avoid outplanting in swales or frost pocket areas; 4) provide shade protection; 5) plant where there is protection from heavy snow loading; and 6) provide adequate growing space.